feat(safety): remote e-stop over 4G MQTT (Issue #63)

STM32 firmware:
- safety.h/c: EstopSource enum, safety_remote_estop/clear/get/active()
  CDC 'E'=ESTOP_REMOTE, 'F'=ESTOP_CELLULAR_TIMEOUT, 'Z'=clear latch
- usbd_cdc_if: cdc_estop_request/cdc_estop_clear_request volatile flags
- status: status_update() +remote_estop param; both LEDs fast-blink 200ms
- main.c: immediate motor cutoff highest-priority; arming gated by
  !safety_remote_estop_active(); motor estop auto-clear gated; telemetry
  'es' field 0-4; status_update() updated to 5 args

Safety: IMMEDIATE motor cutoff, latched until explicit Z + DISARMED,
cannot re-arm via MQTT alone (requires RC arm hold). IWDG-safe.

Jetson bridge:
- remote_estop_node.py: paho-mqtt + pyserial, cellular watchdog 5s
- estop_params.yaml, remote_estop.launch.py
- setup.py / package.xml: register node + paho-mqtt dep
- docker-compose.yml: remote-estop service
- test_remote_estop.py: kill/clear/watchdog/latency unit tests

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

chassis/antenna_mount.scad

@@ -0,0 +1,309 @@
+// ============================================================
+// antenna_mount.scad — LTE + GNSS Antenna Brackets  Rev A
+// 2026-03-01  sl-mechanical
+// ============================================================
+// Stem-mounted brackets for the SIM7600X cellular/GPS system.
+//
+//   lte_bracket()      25 mm stem clamp + arm with 2× SMA
+//                      bulkhead holes (LTE main + diversity).
+//                      Antennas point skyward.
+//
+//   gnss_platform()    25 mm stem clamp + upward-facing tray
+//                      for active GNSS patch antenna (≤40×40 mm).
+//
+// Recommended stem positions (above base plate):
+//   LTE bracket        500–600 mm (above battery carousel)
+//   GNSS platform      750–800 mm (below sensor head, clear sky)
+//
+// Both use the same split-collar design:
+//   M4 clamping bolts + M4 set screw (height lock).
+//   Cable-tie slot on rear half for u.FL pigtail management.
+//
+// u.FL → SMA pigtail cables route down stem to SIM7600X HAT.
+//
+// ⚠  VERIFY:  MAWB_HOLE_X / MAWB_HOLE_Y for any M2.5 pattern
+//             SMA_D for your SMA bulkhead thread OD
+//
+// RENDER options:
+//   "lte_assembly"    LTE bracket view (default)
+//   "lte_front"       LTE collar front half for slicing
+//   "lte_rear"        LTE collar rear half
+//   "lte_arm"         LTE SMA arm for slicing (print flat)
+//   "gnss_assembly"   GNSS platform view
+//   "gnss_front"      GNSS collar front half
+//   "gnss_rear"       GNSS collar rear half
+//   "gnss_tray"       GNSS patch-antenna tray for slicing
+//   "full_stem"       both brackets on 400 mm stem stub
+// ============================================================
+
+RENDER = "lte_assembly";
+
+// ── Stem ─────────────────────────────────────────────────────
+STEM_OD   = 25.0;
+STEM_BORE = 25.4;   // +0.4 clearance
+
+// ── Collar (shared) ──────────────────────────────────────────
+COL_OD      = 52.0;
+COL_H       = 28.0;
+COL_BOLT_X  = 19.0;   // M4 clamping bolt CL from stem axis
+COL_BOLT_D  =  4.5;   // M4 clearance hole
+COL_NUT_W   =  7.0;   // M4 hex nut A/F
+COL_NUT_H   =  3.4;
+
+// Cable-tie slot on rear half outer face (for pigtail routing)
+TIE_W       =  5.0;
+TIE_D       =  3.0;
+TIE_Z1      = COL_H * 0.35;
+TIE_Z2      = COL_H * 0.70;
+
+// ── LTE SMA arm ──────────────────────────────────────────────
+// 2× SMA bulkhead connectors pointing skyward
+SMA_D       =  6.6;   // SMA bulkhead clearance hole (6.35 mm thread)
+SMA_NUT_AF  = 10.2;   // SMA hex-nut capture across-flats
+SMA_NUT_H   =  4.5;   // hex-nut pocket depth (bottom of arm)
+SMA_SPACING = 22.0;   // centre-to-centre between 2 SMA positions
+LTE_ARM_L   = 40.0;   // arm length (from collar OD to SMA CL)
+LTE_ARM_W   = SMA_SPACING + 18.0;  // arm width
+LTE_ARM_H   =  9.0;   // arm thickness
+LTE_SMA_Y   = LTE_ARM_L * 0.65;    // SMA position along arm
+
+// Pigtail cable relief (semi-circular groove on arm underside)
+PIGTAIL_D   =  4.5;
+
+// M3 attachment bolts (arm → collar boss)
+M3_D        =  3.3;
+
+// ── GNSS patch-antenna tray ───────────────────────────────────
+GNSS_PATCH  = 40.0;   // maximum patch antenna side (fits 25, 35, 40 mm)
+GNSS_LIP_T  =  2.2;   // lip wall thickness
+GNSS_LIP_H  =  3.0;   // lip height above tray surface
+GNSS_TRAY_T =  3.0;   // tray base thickness
+
+// Optional M2 bolt-down pattern for larger patch antennas
+GNSS_M2_SP  = 30.0;   // M2 spacing (verify with your patch antenna)
+M2_D        =  2.2;
+
+// Coax cable slot (centre of tray, through base)
+GNSS_COAX_W =  5.5;
+
+// Arm connecting tray to collar
+GNSS_ARM_L  = 28.0;
+GNSS_ARM_W  = 22.0;
+GNSS_ARM_H  =  7.0;
+
+// Spacing between LTE and GNSS collars on stem
+STEM_SPACING = 80.0;
+
+$fn = 64;
+e   = 0.01;
+
+// ─────────────────────────────────────────────────────────────
+// collar_half(side, arm_type)
+//   arm_type: "lte" | "gnss" | "none"
+//   Print flat-face-down.
+// ─────────────────────────────────────────────────────────────
+module collar_half(side="front", arm_type="lte") {
+    y_front = (side == "front");
+    has_arm = y_front && (arm_type != "none");
+
+    arm_w = (arm_type == "lte") ? LTE_ARM_W : GNSS_ARM_W;
+    arm_l = (arm_type == "lte") ? LTE_ARM_L : GNSS_ARM_L;
+    arm_h = (arm_type == "lte") ? LTE_ARM_H : GNSS_ARM_H;
+    arm_z = COL_H/2 - arm_h/2;
+
+    difference() {
+        union() {
+            // D-shaped collar half
+            intersection() {
+                cylinder(d=COL_OD, h=COL_H);
+                translate([-COL_OD/2, y_front ? 0 : -COL_OD/2, 0])
+                    cube([COL_OD, COL_OD/2, COL_H]);
+            }
+
+            // Arm boss integrated into front half
+            if (has_arm)
+                translate([-arm_w/2, COL_OD/2, arm_z])
+                    cube([arm_w, arm_l, arm_h]);
+        }
+
+        // Stem bore
+        translate([0, 0, -e])
+            cylinder(d=STEM_BORE, h=COL_H + 2*e);
+
+        // M4 clamping bolt holes (Y direction)
+        for (bx=[-COL_BOLT_X, COL_BOLT_X])
+            translate([bx, y_front ? COL_OD/2 : 0, COL_H/2])
+                rotate([90,0,0])
+                    cylinder(d=COL_BOLT_D, h=COL_OD/2 + e);
+
+        // M4 hex nut pockets (rear half only)
+        if (!y_front)
+            for (bx=[-COL_BOLT_X, COL_BOLT_X])
+                translate([bx, -(COL_OD/4 + e), COL_H/2])
+                    rotate([90,0,0])
+                        cylinder(d=COL_NUT_W/cos(30), h=COL_NUT_H+e,
+                                 $fn=6);
+
+        // M4 set screw (height lock, front half outer face)
+        if (y_front)
+            translate([0, COL_OD/2, COL_H * 0.75])
+                rotate([90,0,0])
+                    cylinder(d=COL_BOLT_D,
+                             h=COL_OD/2 - STEM_BORE/2 + e);
+
+        // Cable-tie grooves on rear half outer surface (2×)
+        if (!y_front)
+            for (tz=[TIE_Z1, TIE_Z2])
+                translate([-COL_OD/2 - e, -TIE_W/2, tz])
+                    cube([TIE_D + e, TIE_W, TIE_W]);
+
+        // M3 attachment holes through arm boss (2×)
+        if (has_arm)
+            for (dx=[-arm_w/4, arm_w/4])
+                translate([dx, COL_OD/2 + arm_l * 0.45, arm_z - e])
+                    cylinder(d=M3_D, h=arm_h + 2*e);
+    }
+}
+
+// ─────────────────────────────────────────────────────────────
+// lte_sma_arm()
+//   Separate arm piece bolts to collar front boss.
+//   2× SMA bulkheads point upward.  Pigtail grooves on underside.
+//   Print: lay flat on bottom face.
+// ─────────────────────────────────────────────────────────────
+module lte_sma_arm() {
+    difference() {
+        translate([-LTE_ARM_W/2, 0, 0])
+            cube([LTE_ARM_W, LTE_ARM_L, LTE_ARM_H]);
+
+        // 2× SMA bulkhead through-holes (vertical)
+        for (dx=[-SMA_SPACING/2, SMA_SPACING/2]) {
+            translate([dx, LTE_SMA_Y, -e])
+                cylinder(d=SMA_D, h=LTE_ARM_H + 2*e);
+            // Hex-nut pocket from bottom face
+            translate([dx, LTE_SMA_Y, -e])
+                cylinder(d=SMA_NUT_AF/cos(30), h=SMA_NUT_H + e,
+                         $fn=6);
+        }
+
+        // u.FL pigtail relief grooves on underside
+        for (dx=[-SMA_SPACING/2, SMA_SPACING/2])
+            translate([dx, 0, -e])
+                rotate([0, 0, 0])
+                    linear_extrude(PIGTAIL_D/2 + e)
+                        translate([0, LTE_ARM_L/2])
+                            circle(d=PIGTAIL_D);
+
+        // M3 attachment holes (collar boss)
+        for (dx=[-LTE_ARM_W/4, LTE_ARM_W/4])
+            translate([dx, LTE_ARM_L * 0.45, -e])
+                cylinder(d=M3_D, h=LTE_ARM_H + 2*e);
+    }
+}
+
+// ─────────────────────────────────────────────────────────────
+// gnss_tray()
+//   Horizontal tray faces skyward.  Retention lip on all 4 sides.
+//   Central coax slot + optional M2 bolt holes.
+//   Print: top face on bed (tray upside-down → no supports needed).
+// ─────────────────────────────────────────────────────────────
+module gnss_tray() {
+    outer = GNSS_PATCH + 2 * GNSS_LIP_T;
+
+    difference() {
+        union() {
+            // Base plate
+            translate([-outer/2, 0, 0])
+                cube([outer, outer, GNSS_TRAY_T]);
+            // Retention lip (4 walls)
+            translate([-outer/2, 0, GNSS_TRAY_T])
+                difference() {
+                    cube([outer, outer, GNSS_LIP_H]);
+                    translate([GNSS_LIP_T, GNSS_LIP_T, -e])
+                        cube([GNSS_PATCH, GNSS_PATCH, GNSS_LIP_H + 2*e]);
+                }
+            // Arm connecting to collar
+            translate([-GNSS_ARM_W/2, -GNSS_ARM_L, 0])
+                cube([GNSS_ARM_W, GNSS_ARM_L, GNSS_ARM_H]);
+        }
+
+        // GNSS coax cable slot (centre, through base)
+        translate([-GNSS_COAX_W/2, outer/2 - GNSS_COAX_W/2, -e])
+            cube([GNSS_COAX_W, GNSS_COAX_W, GNSS_TRAY_T + 2*e]);
+
+        // M2 bolt-down holes (30×30 mm pattern, centred in tray)
+        tray_cx = 0;
+        tray_cy = outer/2;
+        for (dx=[-GNSS_M2_SP/2, GNSS_M2_SP/2])
+            for (dy=[-GNSS_M2_SP/2, GNSS_M2_SP/2])
+                translate([tray_cx + dx, tray_cy + dy, -e])
+                    cylinder(d=M2_D, h=GNSS_TRAY_T + 2*e);
+
+        // M3 bolt holes (arm → collar)
+        for (dx=[-GNSS_ARM_W/4, GNSS_ARM_W/4])
+            translate([dx, -GNSS_ARM_L * 0.45, -e])
+                cylinder(d=M3_D, h=GNSS_ARM_H + 2*e);
+    }
+}
+
+// ─────────────────────────────────────────────────────────────
+// lte_bracket_assembly() / gnss_bracket_assembly()
+// ─────────────────────────────────────────────────────────────
+module lte_bracket_assembly() {
+    color("SteelBlue",      0.9) collar_half("front", "lte");
+    color("CornflowerBlue", 0.9) mirror([0,1,0]) collar_half("rear", "none");
+    color("LightSteelBlue", 0.85)
+        translate([0, COL_OD/2, COL_H/2 - LTE_ARM_H/2])
+            lte_sma_arm();
+    // Phantom SMA stub antennas
+    for (dx=[-SMA_SPACING/2, SMA_SPACING/2])
+        color("DimGray", 0.5)
+            translate([dx, COL_OD/2 + LTE_SMA_Y,
+                       COL_H/2 + LTE_ARM_H/2])
+                cylinder(d=7, h=60);
+}
+
+module gnss_bracket_assembly() {
+    color("Teal",     0.9) collar_half("front", "gnss");
+    color("DarkCyan", 0.9) mirror([0,1,0]) collar_half("rear", "none");
+    // Tray: arm at Y−, tray faces +Z
+    color("LightCyan", 0.85)
+        translate([0, COL_OD/2 + GNSS_ARM_L,
+                   COL_H/2 - GNSS_ARM_H/2])
+            rotate([90, 0, 0])
+                gnss_tray();
+    // Phantom GNSS patch
+    color("Gold", 0.35)
+        translate([-GNSS_PATCH/2,
+                   COL_OD/2 + GNSS_ARM_L + GNSS_LIP_T,
+                   COL_H/2 + GNSS_ARM_H/2 + GNSS_TRAY_T])
+            cube([GNSS_PATCH, GNSS_PATCH, 8]);
+}
+
+// ─────────────────────────────────────────────────────────────
+// Render selector
+// ─────────────────────────────────────────────────────────────
+if (RENDER == "lte_assembly") {
+    lte_bracket_assembly();
+} else if (RENDER == "lte_front") {
+    collar_half("front", "lte");
+} else if (RENDER == "lte_rear") {
+    collar_half("rear", "none");
+} else if (RENDER == "lte_arm") {
+    translate([0, 0, LTE_ARM_H]) rotate([180,0,0]) lte_sma_arm();
+} else if (RENDER == "gnss_assembly") {
+    gnss_bracket_assembly();
+} else if (RENDER == "gnss_front") {
+    collar_half("front", "gnss");
+} else if (RENDER == "gnss_rear") {
+    collar_half("rear", "none");
+} else if (RENDER == "gnss_tray") {
+    gnss_tray();
+} else if (RENDER == "full_stem") {
+    color("Silver", 0.2)
+        translate([0,0,-40])
+            cylinder(d=STEM_OD, h=STEM_SPACING + COL_H + 80);
+    lte_bracket_assembly();
+    translate([0, 0, STEM_SPACING])
+        gnss_bracket_assembly();
+}

chassis/sim7600x_mount.scad

@@ -0,0 +1,169 @@
+// ============================================================
+// sim7600x_mount.scad — Waveshare SIM7600X 4G HAT Bracket
+// Rev A  2026-03-01  sl-mechanical
+// ============================================================
+// Mounts the SIM7600X HAT near the Jetson Orin on the base plate.
+//
+// PCB: 65 × 56 mm, 4× M2.5 mounting holes (RPi HAT std pattern).
+//
+// SIM card access without disassembly:
+//   The Y− edge of the bracket platform is fully open — a notch
+//   in the floor plate is wider than the SIM tray so the card
+//   inserts / ejects with the board fully installed.
+//
+// Base plate attachment: 4× M3 flat-head countersunk holes at
+// bracket corners.  Drill M3 clearance holes in base plate and
+// use M3 nyloc nuts underneath, or use captured M3 T-nuts.
+//
+// ⚠  VERIFY WITH CALIPERS BEFORE PRINTING:
+//    HAT_L, HAT_W             PCB dimensions
+//    HAT_HOLE_X, HAT_HOLE_Y   M2.5 hole spacing
+//    HAT_HOLE_OX, HAT_HOLE_OY hole inset from PCB corners
+//    SIM_X, SIM_W             SIM slot centre & width on Y− edge
+//    USB_X, USB_W, USB_H      USB port on Y− edge
+//
+// RENDER options:
+//   "assembly"     bracket + phantom PCB (default)
+//   "bracket"      print-ready bracket
+//   "bracket_2d"   floor projection → DXF for base-plate layout
+// ============================================================
+
+RENDER = "assembly";
+
+// ── ⚠ Verify before printing ─────────────────────────────────
+// Waveshare SIM7600X-H 4G HAT
+HAT_L       = 65.0;   // PCB length (X)
+HAT_W       = 56.0;   // PCB width  (Y) — SIM slot on Y=0 edge
+HAT_H_BELOW =  3.0;   // tallest component on PCB underside (verify)
+
+// RPi HAT standard M2.5 hole pattern
+HAT_HOLE_X  = 58.0;   // X span between hole pairs
+HAT_HOLE_Y  = 49.0;   // Y span between hole pairs
+HAT_HOLE_OX =  3.5;   // hole inset from X− edge of PCB
+HAT_HOLE_OY =  3.5;   // hole inset from Y− edge of PCB
+M25_D       =  2.7;   // M2.5 clearance (loose, for alignment)
+M25_OD      =  5.0;   // standoff post outer diameter
+
+// SIM card slot (Y− edge, verify position from left/X− corner)
+SIM_X       = 42.0;   // SIM slot centre from PCB X− edge
+SIM_W       = 17.0;   // SIM slot width
+SIM_H_NOTCH =  4.5;   // notch height for tray travel + eject pin
+
+// USB Micro-B port (Y− edge, verify — may differ by HAT version)
+USB_X       = 11.0;   // USB port centre from PCB X− edge
+USB_W       = 10.5;   // USB port width
+USB_H       =  7.0;   // USB port height
+
+// u.FL pigtail exit slot (Y+ wall)
+UFL_SLOT_W  = 12.0;
+UFL_SLOT_H  =  5.0;
+
+// ── Bracket geometry ─────────────────────────────────────────
+STNDFF_H    = HAT_H_BELOW + 4.0;   // standoff height (clears underside)
+PLAT_T      =  3.5;   // floor plate thickness
+WALL_T      =  2.5;   // side wall thickness
+
+PAD_X       =  5.0;   // platform extends PAD_X beyond PCB on X± sides
+PAD_Y_PLUS  =  8.0;   // platform extends PAD_Y_PLUS beyond PCB on Y+ side
+// Y− side: open (no wall, no floor overhang) — SIM/USB access
+
+PLAT_L      = HAT_L + 2 * PAD_X;
+PLAT_W      = HAT_W + PAD_Y_PLUS;   // Y− edge flush with PCB Y=0
+
+// PCB sits with Y=0 edge flush with bracket Y=0 face
+PCB_X0      = PAD_X;   // X offset of PCB within bracket
+
+// M3 base-plate mounting holes
+M3_D        =  3.4;
+M3_CS_D     =  6.2;   // flat-head countersink diameter
+M3_CS_H     =  3.0;   // countersink depth (from bottom face)
+M3_INSET    =  5.0;   // hole inset from bracket corner
+
+// Side wall height (for cable containment)
+WALL_H      = STNDFF_H + 4.0;
+
+$fn = 48;
+e   = 0.01;
+
+// ─────────────────────────────────────────────────────────────
+module sim7600x_bracket() {
+    difference() {
+        union() {
+            // ── Floor plate ──────────────────────────────────
+            cube([PLAT_L, PLAT_W, PLAT_T]);
+
+            // ── Side walls: X−, X+, Y+ only (Y− open) ───────
+            translate([0, 0, 0])
+                cube([WALL_T, PLAT_W, WALL_H]);
+            translate([PLAT_L - WALL_T, 0, 0])
+                cube([WALL_T, PLAT_W, WALL_H]);
+            translate([0, PLAT_W - WALL_T, 0])
+                cube([PLAT_L, WALL_T, WALL_H]);
+
+            // ── M2.5 standoff posts (×4) ─────────────────────
+            for (hx=[0, HAT_HOLE_X], hy=[0, HAT_HOLE_Y])
+                translate([PCB_X0 + HAT_HOLE_OX + hx,
+                           HAT_HOLE_OY + hy,
+                           PLAT_T])
+                    cylinder(d=M25_OD, h=STNDFF_H);
+        }
+
+        // ── M2.5 clearance bores through standoffs ───────────
+        for (hx=[0, HAT_HOLE_X], hy=[0, HAT_HOLE_Y])
+            translate([PCB_X0 + HAT_HOLE_OX + hx,
+                       HAT_HOLE_OY + hy, -e])
+                cylinder(d=M25_D, h=PLAT_T + STNDFF_H + e);
+
+        // ── SIM card access notch (Y− face of floor) ─────────
+        // Notch 4 mm wider than SIM slot each side
+        translate([PCB_X0 + SIM_X - SIM_W/2 - 4, -e, -e])
+            cube([SIM_W + 8, WALL_T + e, PLAT_T + SIM_H_NOTCH + e]);
+
+        // ── USB port access notch (Y− face of X− wall) ───────
+        translate([PCB_X0 + USB_X - USB_W/2, -e,
+                   PLAT_T + STNDFF_H/2 - USB_H/2])
+            cube([USB_W, WALL_T + 2*e, USB_H]);
+
+        // ── u.FL pigtail exit slot (Y+ wall, upper zone) ─────
+        translate([PLAT_L/2 - UFL_SLOT_W/2,
+                   PLAT_W - WALL_T - e,
+                   PLAT_T + STNDFF_H - UFL_SLOT_H])
+            cube([UFL_SLOT_W, WALL_T + 2*e, UFL_SLOT_H + e]);
+
+        // ── M3 base-plate mounting holes (×4, countersunk) ───
+        for (cx=[M3_INSET, PLAT_L - M3_INSET])
+            for (cy=[M3_INSET, PLAT_W - M3_INSET]) {
+                translate([cx, cy, -e])
+                    cylinder(d=M3_D, h=PLAT_T + 2*e);
+                // Countersink from bottom face
+                translate([cx, cy, -e])
+                    cylinder(d1=M3_CS_D, d2=M3_D,
+                             h=M3_CS_H + e);
+            }
+
+        // ── Cable relief notch in X+ wall ────────────────────
+        translate([PLAT_L - WALL_T - e, PLAT_W * 0.35, PLAT_T + 2])
+            cube([WALL_T + 2*e, 9, 5]);
+    }
+}
+
+// ─────────────────────────────────────────────────────────────
+if (RENDER == "assembly") {
+    color("DimGray", 0.92) sim7600x_bracket();
+    // Phantom PCB
+    color("ForestGreen", 0.3)
+        translate([PCB_X0, 0, PLAT_T + STNDFF_H])
+            cube([HAT_L, HAT_W, 1.6]);
+    // SIM access marker (yellow arrow zone)
+    color("Gold", 0.7)
+        translate([PCB_X0 + SIM_X - 10, -8, 0])
+            cube([20, 8, 2]);
+
+} else if (RENDER == "bracket") {
+    sim7600x_bracket();
+
+} else if (RENDER == "bracket_2d") {
+    projection(cut=true)
+        translate([0, 0, -PLAT_T/2])
+            sim7600x_bracket();
+}

include/safety.h

@@ -12,8 +12,17 @@
  *  - RC signal timeout monitoring
  *  - Tilt fault alert via buzzer
  *  - Arm hold interlock (must hold arm for ARMING_HOLD_MS)
+ *  - Remote e-stop over 4G MQTT (CDC 'E'/'F'/'Z' commands)
  */
 
+typedef enum {
+    ESTOP_CLEAR            = 0,
+    ESTOP_TILT             = 1,
+    ESTOP_RC_KILL          = 2,
+    ESTOP_REMOTE           = 3,
+    ESTOP_CELLULAR_TIMEOUT = 4,
+} EstopSource;
+
 /*
  * safety_init() — call once in main() after HAL_Init().
  * Starts IWDG with WATCHDOG_TIMEOUT_MS timeout from config.h.
@@ -48,4 +57,9 @@ void safety_arm_start(uint32_t now);  /* Call when arm requested */
 bool safety_arm_ready(uint32_t now);  /* Poll until true, then arm */
 void safety_arm_cancel(void);         /* Cancel pending arm */
 
+void        safety_remote_estop(EstopSource src);
+void        safety_remote_estop_clear(void);
+EstopSource safety_get_estop(void);
+bool        safety_remote_estop_active(void);
+
 #endif /* SAFETY_H */

include/status.h

@@ -13,7 +13,8 @@ void status_boot_beep(void);
  *  LED1 solid + LED2 off  → disarmed, IMU OK
  *  LED1 solid + LED2 solid → armed
  *  Both slow blink         → tilt fault
+ *  Both fast blink (200ms) -- remote e-stop active (highest priority)
  *  LED1 slow blink + LED2 solid → IMU error (solid LED2 = always-on indicator)
  */
-void status_update(uint32_t tick, int imu_ok, int armed, int tilt_fault);
+void status_update(uint32_t tick, int imu_ok, int armed, int tilt_fault, int remote_estop);
 #endif

jetson/docker-compose.yml

@@ -14,44 +14,30 @@ services:
       dockerfile: Dockerfile
     container_name: saltybot-ros2
     restart: unless-stopped
-    runtime: nvidia                 # JetPack NVIDIA runtime
-    privileged: false               # use device passthrough instead
-    network_mode: host              # ROS2 DDS multicast needs host networking
-
+    runtime: nvidia
+    privileged: false
+    network_mode: host
     environment:
       - NVIDIA_VISIBLE_DEVICES=all
       - NVIDIA_DRIVER_CAPABILITIES=all
       - RMW_IMPLEMENTATION=rmw_cyclonedds_cpp
       - ROS_DOMAIN_ID=42
-      - DISPLAY=${DISPLAY:-:0}      # for RViz2 on host X11
-
+      - DISPLAY=${DISPLAY:-:0}
     volumes:
-      # X11 socket for RViz2
       - /tmp/.X11-unix:/tmp/.X11-unix:rw
-      # ROS2 workspace (host-mounted for live dev)
       - ./ros2_ws/src:/ros2_ws/src:rw
-      # Persistent SLAM maps on NVMe
       - /mnt/nvme/saltybot/maps:/maps
-      # NVMe data volume
       - /mnt/nvme/saltybot:/data:rw
-      # Config files
       - ./config:/config:ro
-
     devices:
-      # RPLIDAR A1M8 — stable symlink via udev
       - /dev/rplidar:/dev/rplidar
-      # STM32 USB CDC bridge — stable symlink via udev
       - /dev/stm32-bridge:/dev/stm32-bridge
-      # RealSense D435i — USB3 device, needs udev rules
       - /dev/bus/usb:/dev/bus/usb
-      # I2C bus (Orin Nano i2c-7 = 40-pin header pins 3/5)
       - /dev/i2c-7:/dev/i2c-7
-      # CSI cameras via V4L2
       - /dev/video0:/dev/video0
       - /dev/video2:/dev/video2
       - /dev/video4:/dev/video4
       - /dev/video6:/dev/video6
-
     command: >
       bash -c "
         source /opt/ros/humble/setup.bash &&
@@ -111,7 +97,7 @@ services:
           rgb_camera.profile:=640x480x30
       "
 
-  # ── STM32 bridge node (bidirectional serial↔ROS2) ─────────────────────────
+  # ── STM32 bridge node (bidirectional serial<->ROS2) ────────────────────────
   stm32-bridge:
     image: saltybot/ros2-humble:jetson-orin
     build:
@@ -134,7 +120,7 @@ services:
           serial_port:=/dev/stm32-bridge
       "
 
-  # ── 4× IMX219 CSI cameras ─────────────────────────────────────────────────
+  # ── 4x IMX219 CSI cameras ──────────────────────────────────────────────────
   csi-cameras:
     image: saltybot/ros2-humble:jetson-orin
     build:
@@ -144,7 +130,7 @@ services:
     restart: unless-stopped
     runtime: nvidia
     network_mode: host
-    privileged: true                # CSI camera access requires elevated perms
+    privileged: true
     environment:
       - ROS_DOMAIN_ID=42
       - RMW_IMPLEMENTATION=rmw_cyclonedds_cpp
@@ -164,22 +150,8 @@ services:
           fps:=30
       "
 
-  # ── Surround vision — 360° bird's-eye view + Nav2 camera obstacle layer ─────
+  # ── Surround vision — 360 bird's-eye view + Nav2 camera obstacle layer ─────
   saltybot-surround:
-
-  # ── rosbridge WebSocket server ────────────────────────────────────────────
-  # Serves ROS2 topics to the web dashboard (roslibjs) on ws://jetson:9090
-  #
-  # Topics exposed (whitelist in ros2_ws/src/saltybot_bringup/config/rosbridge_params.yaml):
-  #   /map  /scan  /tf  /tf_static  /saltybot/imu  /saltybot/balance_state
-  #   /cmd_vel  /person/*  /camera/*/image_raw/compressed
-  #
-  # Also runs image_transport/republish nodes to compress 4× CSI camera streams.
-  # Raw 640×480 YUYV → JPEG-compressed sensor_msgs/CompressedImage.
-  #
-  # Install (already in image): apt install ros-humble-rosbridge-server
-  #                                         ros-humble-image-transport-plugins
-  rosbridge:
     image: saltybot/ros2-humble:jetson-orin
     build:
       context: .
@@ -189,7 +161,7 @@ services:
     runtime: nvidia
     network_mode: host
     depends_on:
-      - csi-cameras                 # IMX219 /camera/*/image_raw must be publishing
+      - csi-cameras
     environment:
       - NVIDIA_VISIBLE_DEVICES=all
       - NVIDIA_DRIVER_CAPABILITIES=all
@@ -201,28 +173,33 @@ services:
     command: >
       bash -c "
         source /opt/ros/humble/setup.bash &&
+        source /ros2_ws/install/local_setup.bash 2>/dev/null || true &&
         ros2 launch saltybot_surround surround_vision.launch.py
           start_cameras:=false
           camera_height:=0.30
           publish_rate:=5.0
+      "
 
+  # ── rosbridge WebSocket server — ws://jetson:9090 ──────────────────────────
+  rosbridge:
+    image: saltybot/ros2-humble:jetson-orin
+    build:
+      context: .
+      dockerfile: Dockerfile
     container_name: saltybot-rosbridge
     restart: unless-stopped
     runtime: nvidia
-    network_mode: host            # port 9090 is directly reachable on host
+    network_mode: host
     depends_on:
-      - saltybot-ros2             # needs /map, /tf published
-      - stm32-bridge              # needs /saltybot/imu, /saltybot/balance_state
-      - csi-cameras               # needs /camera/*/image_raw for compression
+      - saltybot-ros2
+      - stm32-bridge
+      - csi-cameras
     environment:
       - ROS_DOMAIN_ID=42
       - RMW_IMPLEMENTATION=rmw_cyclonedds_cpp
     volumes:
       - ./ros2_ws/src:/ros2_ws/src:rw
       - ./config:/config:ro
-    # Port 9090 is accessible on all host interfaces via network_mode: host.
-    # To restrict to a specific interface, set host: "192.168.x.x" in
-    # rosbridge_params.yaml instead of using Docker port mappings.
     command: >
       bash -c "
         source /opt/ros/humble/setup.bash &&
@@ -230,7 +207,38 @@ services:
         ros2 launch saltybot_bringup rosbridge.launch.py
       "
 
-  # ── Nav2 autonomous navigation stack ────────────────────────────────────────
+
+  # -- Remote e-stop bridge (MQTT over 4G -> STM32 CDC) ----------------------
+  # Subscribes to saltybot/estop MQTT topic. {"kill":true} -> 'E\r\n' to STM32.
+  # Cellular watchdog: 5s MQTT drop in AUTO mode -> 'F\r\n' (ESTOP_CELLULAR_TIMEOUT).
+  remote-estop:
+    image: saltybot/ros2-humble:jetson-orin
+    build:
+      context: .
+      dockerfile: Dockerfile
+    container_name: saltybot-remote-estop
+    restart: unless-stopped
+    runtime: nvidia
+    network_mode: host
+    depends_on:
+      - stm32-bridge
+    environment:
+      - ROS_DOMAIN_ID=42
+      - RMW_IMPLEMENTATION=rmw_cyclonedds_cpp
+    devices:
+      - /dev/stm32-bridge:/dev/stm32-bridge
+    volumes:
+      - ./ros2_ws/src:/ros2_ws/src:rw
+      - ./config:/config:ro
+    command: >
+      bash -c "
+        source /opt/ros/humble/setup.bash &&
+        source /ros2_ws/install/local_setup.bash 2>/dev/null || true &&
+        pip install paho-mqtt --quiet 2>/dev/null || true &&
+        ros2 launch saltybot_bridge remote_estop.launch.py
+      "
+
+  # ── Nav2 autonomous navigation stack ──────────────────────────────────────
   saltybot-nav2:
     image: saltybot/ros2-humble:jetson-orin
     build:
@@ -241,7 +249,7 @@ services:
     runtime: nvidia
     network_mode: host
     depends_on:
-      - saltybot-ros2               # RTAB-Map + sensors must be running first
+      - saltybot-ros2
     environment:
       - NVIDIA_VISIBLE_DEVICES=all
       - NVIDIA_DRIVER_CAPABILITIES=all
@@ -253,9 +261,47 @@ services:
     command: >
       bash -c "
         source /opt/ros/humble/setup.bash &&
+        source /ros2_ws/install/local_setup.bash 2>/dev/null || true &&
         ros2 launch saltybot_bringup nav2.launch.py
       "
 
+  # ── Outdoor navigation — OSM routing + GPS waypoints + geofence ───────────
+  # Start only for outdoor missions. Usage:
+  #   ros2 param set /osm_router goal_lat 37.7749
+  #   ros2 param set /osm_router goal_lon -122.4194
+  #   ros2 service call /outdoor/plan_route std_srvs/srv/Trigger '{}'
+  #   ros2 service call /outdoor/start_navigation std_srvs/srv/Trigger '{}'
+  saltybot-outdoor:
+    image: saltybot/ros2-humble:jetson-orin
+    build:
+      context: .
+      dockerfile: Dockerfile
+    container_name: saltybot-outdoor
+    restart: unless-stopped
+    runtime: nvidia
+    network_mode: host
+    depends_on:
+      - saltybot-nav2
+    environment:
+      - NVIDIA_VISIBLE_DEVICES=all
+      - NVIDIA_DRIVER_CAPABILITIES=all
+      - RMW_IMPLEMENTATION=rmw_cyclonedds_cpp
+      - ROS_DOMAIN_ID=42
+    volumes:
+      - ./ros2_ws/src:/ros2_ws/src:rw
+      - ./config:/config:ro
+      - /mnt/nvme/saltybot/osm_cache:/data/osm_cache:rw
+    devices:
+      - /dev/sim7600:/dev/sim7600
+    command: >
+      bash -c "
+        source /opt/ros/humble/setup.bash &&
+        source /ros2_ws/install/local_setup.bash 2>/dev/null || true &&
+        ros2 launch saltybot_outdoor outdoor_nav.launch.py
+          use_rtk:=false
+          fence_active:=true
+      "
+
 volumes:
   saltybot-maps:
     driver: local

jetson/ros2_ws/src/saltybot_bridge/config/estop_params.yaml

@@ -0,0 +1,12 @@
+remote_estop_node:
+  ros__parameters:
+    serial_port:               /dev/stm32-bridge
+    baud_rate:                 921600
+    mqtt_host:                 "mqtt.example.com"
+    mqtt_port:                 1883
+    mqtt_user:                 "saltybot"
+    mqtt_password:             ""
+    mqtt_topic:                "saltybot/estop"
+    cellular_timeout_s:        5.0
+    auto_estop_on_disconnect:  true
+    mqtt_keepalive:            10

jetson/ros2_ws/src/saltybot_bridge/launch/remote_estop.launch.py

@@ -0,0 +1,18 @@
+from launch import LaunchDescription
+from launch_ros.actions import Node
+import os
+from ament_index_python.packages import get_package_share_directory
+
+
+def generate_launch_description():
+    pkg = get_package_share_directory('saltybot_bridge')
+    params_file = os.path.join(pkg, 'config', 'estop_params.yaml')
+    return LaunchDescription([
+        Node(
+            package='saltybot_bridge',
+            executable='remote_estop_node',
+            name='remote_estop_node',
+            parameters=[params_file],
+            output='screen',
+        ),
+    ])

jetson/ros2_ws/src/saltybot_bridge/package.xml

@@ -12,6 +12,7 @@
   <license>MIT</license>
 
   <depend>rclpy</depend>
+  <depend>python3-paho-mqtt</depend>
   <depend>sensor_msgs</depend>
   <depend>std_msgs</depend>
   <depend>diagnostic_msgs</depend>

jetson/ros2_ws/src/saltybot_bridge/saltybot_bridge/remote_estop_node.py

@@ -0,0 +1,167 @@
+"""
+remote_estop_node.py -- Remote e-stop bridge: MQTT -> STM32 USB CDC
+
+{"kill": true}  -> writes 'E\n' to STM32 (ESTOP_REMOTE, immediate motor cutoff)
+{"kill": false} -> writes 'Z\n' to STM32 (clear latch, robot can re-arm)
+
+Cellular watchdog: if MQTT link drops for > cellular_timeout_s while in
+AUTO mode, automatically sends 'F\n' (ESTOP_CELLULAR_TIMEOUT).
+
+Publishes /saltybot/estop_active (std_msgs/Bool).
+"""
+
+import json
+import time
+import threading
+
+import rclpy
+from rclpy.node import Node
+from std_msgs.msg import Bool, String
+
+import paho.mqtt.client as mqtt
+import serial
+
+
+class RemoteEstopNode(Node):
+    def __init__(self):
+        super().__init__('remote_estop_node')
+
+        self.declare_parameter('serial_port', '/dev/stm32-bridge')
+        self.declare_parameter('baud_rate', 921600)
+        self.declare_parameter('mqtt_host', 'mqtt.example.com')
+        self.declare_parameter('mqtt_port', 1883)
+        self.declare_parameter('mqtt_user', 'saltybot')
+        self.declare_parameter('mqtt_password', '')
+        self.declare_parameter('mqtt_topic', 'saltybot/estop')
+        self.declare_parameter('cellular_timeout_s', 5.0)
+        self.declare_parameter('auto_estop_on_disconnect', True)
+        self.declare_parameter('mqtt_keepalive', 10)
+
+        self._serial_port = self.get_parameter('serial_port').value
+        self._baud_rate = self.get_parameter('baud_rate').value
+        self._mqtt_host = self.get_parameter('mqtt_host').value
+        self._mqtt_port = self.get_parameter('mqtt_port').value
+        self._mqtt_user = self.get_parameter('mqtt_user').value
+        self._mqtt_password = self.get_parameter('mqtt_password').value
+        self._mqtt_topic = self.get_parameter('mqtt_topic').value
+        self._cellular_timeout_s = self.get_parameter('cellular_timeout_s').value
+        self._auto_estop_on_disconnect = self.get_parameter('auto_estop_on_disconnect').value
+        self._mqtt_keepalive = self.get_parameter('mqtt_keepalive').value
+
+        self._ser = serial.Serial(self._serial_port, self._baud_rate, timeout=0.1)
+        self._estop_pub = self.create_publisher(Bool, '/saltybot/estop_active', 10)
+        self._mode_sub = self.create_subscription(
+            String, '/saltybot/balance_state', self._balance_state_cb, 10)
+        self._auto_mode = False
+        self._estop_active = False
+        self._last_mqtt_ok = time.monotonic()
+        self._watchdog_fired = False
+        self._lock = threading.Lock()
+
+        self._mqtt = mqtt.Client(client_id='saltybot-estop')
+        self._mqtt.username_pw_set(self._mqtt_user, self._mqtt_password)
+        self._mqtt.on_connect = self._on_mqtt_connect
+        self._mqtt.on_disconnect = self._on_mqtt_disconnect
+        self._mqtt.on_message = self._on_mqtt_message
+        self._mqtt.will_set(self._mqtt_topic + '/status', 'OFFLINE', qos=1, retain=True)
+        try:
+            self._mqtt.connect_async(self._mqtt_host, self._mqtt_port, self._mqtt_keepalive)
+            self._mqtt.loop_start()
+        except Exception as e:
+            self.get_logger().error(f'MQTT connect failed: {e}')
+
+        self.create_timer(1.0, self._watchdog_cb)
+        self.get_logger().info(
+            f'remote_estop_node started -- MQTT {self._mqtt_host}:{self._mqtt_port}')
+
+    def _on_mqtt_connect(self, client, userdata, flags, rc):
+        if rc == 0:
+            client.subscribe(self._mqtt_topic, qos=1)
+            with self._lock:
+                self._last_mqtt_ok = time.monotonic()
+                self._watchdog_fired = False
+        else:
+            self.get_logger().warning(f'MQTT connect refused rc={rc}')
+
+    def _on_mqtt_disconnect(self, client, userdata, rc):
+        self.get_logger().warning(f'MQTT disconnected rc={rc}')
+
+    def _on_mqtt_message(self, client, userdata, msg):
+        with self._lock:
+            self._last_mqtt_ok = time.monotonic()
+            self._watchdog_fired = False
+        try:
+            payload = json.loads(msg.payload.decode('utf-8'))
+            kill = payload.get('kill', False)
+        except (json.JSONDecodeError, UnicodeDecodeError) as e:
+            self.get_logger().error(f'Bad MQTT payload: {e}')
+            return
+        if kill:
+            self._send_estop('E')
+            self.get_logger().warning('MQTT kill=true -> ESTOP_REMOTE')
+        else:
+            self._send_clear()
+            self.get_logger().info('MQTT kill=false -> estop clear')
+
+    def _balance_state_cb(self, msg: String):
+        self._auto_mode = '"md":2' in msg.data
+
+    def _watchdog_cb(self):
+        if not self._auto_estop_on_disconnect:
+            return
+        with self._lock:
+            elapsed = time.monotonic() - self._last_mqtt_ok
+            fired = self._watchdog_fired
+        if self._auto_mode and elapsed > self._cellular_timeout_s and not fired:
+            with self._lock:
+                self._watchdog_fired = True
+            self.get_logger().error(
+                f'Cellular link lost {elapsed:.1f}s in AUTO mode -> ESTOP_CELLULAR_TIMEOUT')
+            self._send_estop('F')
+
+    def _send_estop(self, cmd: str):
+        try:
+            self._ser.write(f'{cmd}\n'.encode())
+            self._ser.flush()
+        except serial.SerialException as e:
+            self.get_logger().error(f'Serial write error: {e}')
+        with self._lock:
+            self._estop_active = True
+        msg = Bool()
+        msg.data = True
+        self._estop_pub.publish(msg)
+
+    def _send_clear(self):
+        try:
+            self._ser.write(b'Z\n')
+            self._ser.flush()
+        except serial.SerialException as e:
+            self.get_logger().error(f'Serial write error: {e}')
+        with self._lock:
+            self._estop_active = False
+        msg = Bool()
+        msg.data = False
+        self._estop_pub.publish(msg)
+
+    def destroy_node(self):
+        self._mqtt.loop_stop()
+        self._mqtt.disconnect()
+        if self._ser.is_open:
+            self._ser.close()
+        super().destroy_node()
+
+
+def main(args=None):
+    rclpy.init(args=args)
+    node = RemoteEstopNode()
+    try:
+        rclpy.spin(node)
+    except KeyboardInterrupt:
+        pass
+    finally:
+        node.destroy_node()
+        rclpy.shutdown()
+
+
+if __name__ == '__main__':
+    main()

jetson/ros2_ws/src/saltybot_bridge/setup.py

@@ -12,10 +12,12 @@ setup(
         (f"share/{package_name}/launch", [
             "launch/bridge.launch.py",
             "launch/cmd_vel_bridge.launch.py",
+            "launch/remote_estop.launch.py",
         ]),
         (f"share/{package_name}/config", [
             "config/bridge_params.yaml",
             "config/cmd_vel_bridge_params.yaml",
+            "config/estop_params.yaml",
         ]),
     ],
     install_requires=["setuptools", "pyserial"],
@@ -33,6 +35,7 @@ setup(
             "saltybot_cmd_node  = saltybot_bridge.saltybot_cmd_node:main",
             # Nav2 cmd_vel bridge: velocity limits + ramp + deadman + mode gate
             "cmd_vel_bridge_node = saltybot_bridge.cmd_vel_bridge_node:main",
+            "remote_estop_node = saltybot_bridge.remote_estop_node:main",
         ],
     },
 )

jetson/ros2_ws/src/saltybot_bridge/test/test_remote_estop.py

@@ -0,0 +1,105 @@
+"""Unit tests for remote_estop_node."""
+
+import json
+import time
+import threading
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+
+def make_node(auto_estop=True, timeout=0.2):
+    with patch("saltybot_bridge.remote_estop_node.serial.Serial"), \
+         patch("saltybot_bridge.remote_estop_node.mqtt.Client"), \
+         patch("saltybot_bridge.remote_estop_node.rclpy"), \
+         patch("saltybot_bridge.remote_estop_node.Node.__init__", return_value=None):
+
+        from saltybot_bridge.remote_estop_node import RemoteEstopNode
+        node = RemoteEstopNode.__new__(RemoteEstopNode)
+        node._ser = MagicMock()
+        node._ser.is_open = True
+        node._mqtt = MagicMock()
+        node._mqtt_host = "localhost"
+        node._mqtt_port = 1883
+        node._mqtt_user = "test"
+        node._mqtt_password = ""
+        node._mqtt_topic = "test/estop"
+        node._mqtt_keepalive = 10
+        node._cellular_timeout_s = timeout
+        node._auto_estop_on_disconnect = auto_estop
+        node._auto_mode = False
+        node._estop_active = False
+        node._last_mqtt_ok = time.monotonic()
+        node._watchdog_fired = False
+        node._lock = threading.Lock()
+        node._estop_pub = MagicMock()
+        node.get_logger = MagicMock(return_value=MagicMock(
+            info=MagicMock(), warning=MagicMock(), error=MagicMock()))
+        return node
+
+
+def mqtt_msg(payload_dict):
+    msg = MagicMock()
+    msg.payload = json.dumps(payload_dict).encode()
+    return msg
+
+
+def test_kill_true_sends_E():
+    node = make_node()
+    t0 = time.monotonic()
+    node._on_mqtt_message(None, None, mqtt_msg({"kill": True}))
+    assert (time.monotonic() - t0) < 0.5
+    node._ser.write.assert_called_once_with(b'E\n')
+
+
+def test_kill_false_sends_Z():
+    node = make_node()
+    node._on_mqtt_message(None, None, mqtt_msg({"kill": False}))
+    node._ser.write.assert_called_once_with(b'Z\n')
+
+
+def test_kill_true_publishes_active_true():
+    node = make_node()
+    node._on_mqtt_message(None, None, mqtt_msg({"kill": True}))
+    assert node._estop_pub.publish.call_args[0][0].data is True
+
+
+def test_bad_json_no_write():
+    node = make_node()
+    bad = MagicMock()
+    bad.payload = b"NOT JSON"
+    node._on_mqtt_message(None, None, bad)
+    node._ser.write.assert_not_called()
+
+
+def test_watchdog_fires_F_in_auto_after_timeout():
+    node = make_node(auto_estop=True, timeout=0.05)
+    node._auto_mode = True
+    node._last_mqtt_ok = time.monotonic() - 1.0
+    node._watchdog_cb()
+    node._ser.write.assert_called_once_with(b'F\n')
+
+
+def test_watchdog_no_fire_if_not_auto():
+    node = make_node(auto_estop=True, timeout=0.05)
+    node._auto_mode = False
+    node._last_mqtt_ok = time.monotonic() - 1.0
+    node._watchdog_cb()
+    node._ser.write.assert_not_called()
+
+
+def test_watchdog_only_fires_once():
+    node = make_node(auto_estop=True, timeout=0.05)
+    node._auto_mode = True
+    node._last_mqtt_ok = time.monotonic() - 1.0
+    node._watchdog_cb()
+    node._watchdog_cb()
+    assert node._ser.write.call_count == 1
+
+
+def test_watchdog_disabled_by_param():
+    node = make_node(auto_estop=False, timeout=0.05)
+    node._auto_mode = True
+    node._last_mqtt_ok = time.monotonic() - 1.0
+    node._watchdog_cb()
+    node._ser.write.assert_not_called()

jetson/ros2_ws/src/saltybot_bringup/launch/full_stack.launch.py

@@ -0,0 +1,472 @@
+"""
+full_stack.launch.py — One-command full autonomous stack bringup for SaltyBot.
+
+Launches the ENTIRE software stack in dependency order with configurable modes.
+
+Usage
+─────
+  # Full indoor autonomous (SLAM + Nav2 + person follow + UWB):
+  ros2 launch saltybot_bringup full_stack.launch.py
+
+  # Person-follow only (no SLAM, no Nav2 — living room demo):
+  ros2 launch saltybot_bringup full_stack.launch.py mode:=follow
+
+  # Outdoor GPS nav + person follow:
+  ros2 launch saltybot_bringup full_stack.launch.py mode:=outdoor
+
+  # Indoor, no CSI cameras (RealSense + RPLIDAR only):
+  ros2 launch saltybot_bringup full_stack.launch.py mode:=indoor enable_csi_cameras:=false
+
+  # Simulation / rosbag replay:
+  ros2 launch saltybot_bringup full_stack.launch.py use_sim_time:=true enable_bridge:=false
+
+Modes
+─────
+  indoor  (default)
+    ─ RPLIDAR + RealSense D435i sensors
+    ─ RTAB-Map SLAM (RGB-D + LIDAR, fresh map each boot)
+    ─ Nav2 navigation stack (planners, controllers, BT navigator)
+    ─ CSI 4× IMX219 surround cameras (optional, default on)
+    ─ UWB driver (2-anchor DW3000, publishes /uwb/target)
+    ─ YOLOv8n person detection (TensorRT)
+    ─ Person follower with UWB+camera fusion
+    ─ cmd_vel bridge → STM32 (deadman + ramp + AUTONOMOUS gate)
+    ─ rosbridge WebSocket (port 9090)
+
+  outdoor
+    ─ RPLIDAR + RealSense D435i sensors (no SLAM)
+    ─ GPS-based outdoor navigation (robot_localization EKF + Nav2)
+    ─ UWB + person detection + follower
+    ─ cmd_vel bridge + rosbridge
+
+  follow
+    ─ RealSense D435i + RPLIDAR only (no SLAM, no Nav2)
+    ─ UWB + person detection + follower
+    ─ cmd_vel bridge + rosbridge
+    ─ Note: obstacle avoidance disabled (no Nav2 local costmap)
+
+Launch sequence (wall-clock delays — conservative for cold start)
+─────────────────────────────────────────────────────────────────
+   t= 0s  robot_description   (URDF + TF tree)
+   t= 0s  STM32 bridge        (serial port owner — must be first)
+   t= 2s  cmd_vel bridge      (consumes /cmd_vel, needs STM32 bridge up)
+   t= 2s  sensors             (RPLIDAR + RealSense)
+   t= 4s  UWB driver          (independent serial device)
+   t= 4s  CSI cameras         (optional, independent)
+   t= 6s  SLAM / outdoor nav  (needs sensors; indoor/outdoor mode only)
+   t= 6s  person detection    (needs RealSense up)
+   t=14s  Nav2                (needs SLAM to have partial map; indoor only)
+   t= 9s  person follower     (needs perception + UWB)
+   t=17s  rosbridge           (last — exposes all topics over WebSocket)
+
+Safety wiring
+─────────────
+  • STM32 bridge must be up before cmd_vel bridge sends any command.
+  • cmd_vel bridge has 500ms deadman: stops robot if /cmd_vel goes silent.
+  • STM32 AUTONOMOUS mode gate (md=2) in cmd_vel bridge — robot stays still
+    until STM32 firmware is in AUTONOMOUS mode regardless of /cmd_vel.
+  • follow_enabled:=false disables person follower without stopping the node.
+  • To e-stop at runtime: ros2 topic pub /saltybot/estop std_msgs/Bool '{data: true}'
+
+Topics published by this stack
+───────────────────────────────
+  /scan                            RPLIDAR LaserScan
+  /camera/color/image_raw          RealSense RGB
+  /camera/depth/image_rect_raw     RealSense depth
+  /camera/imu                      RealSense IMU
+  /rtabmap/map                     OccupancyGrid  (indoor only)
+  /rtabmap/odom                    Odometry       (indoor only)
+  /uwb/target                      PoseStamped    (UWB position, base_link)
+  /uwb/ranges                      UwbRangeArray  (raw anchor ranges)
+  /person/target                   PoseStamped    (camera position, base_link)
+  /person/detections               Detection2DArray
+  /cmd_vel                         Twist          (from follower or Nav2)
+  /saltybot/cmd                    String         (to STM32)
+  /saltybot/imu                    Imu
+  /saltybot/balance_state          String
+"""
+
+import os
+
+from ament_index_python.packages import get_package_share_directory
+from launch import LaunchDescription
+from launch.actions import (
+    DeclareLaunchArgument,
+    GroupAction,
+    IncludeLaunchDescription,
+    LogInfo,
+    TimerAction,
+)
+from launch.conditions import IfCondition
+from launch.launch_description_sources import PythonLaunchDescriptionSource
+from launch.substitutions import LaunchConfiguration, PythonExpression
+
+
+# ── Convenience: package share paths ──────────────────────────────────────────
+
+def _pkg(name: str) -> str:
+    return get_package_share_directory(name)
+
+
+def _launch(pkg: str, *parts: str) -> PythonLaunchDescriptionSource:
+    return PythonLaunchDescriptionSource(os.path.join(_pkg(pkg), *parts))
+
+
+# ── Mode helpers ───────────────────────────────────────────────────────────────
+
+def _mode_is(mode_str: str):
+    """IfCondition: true when 'mode' arg == mode_str."""
+    return IfCondition(
+        PythonExpression(["'", LaunchConfiguration("mode"), f"' == '{mode_str}'"])
+    )
+
+
+def _mode_in(*modes):
+    """IfCondition: true when 'mode' arg is one of the given strings."""
+    mode_set = repr(set(modes))
+    return IfCondition(
+        PythonExpression(["'", LaunchConfiguration("mode"), f"' in {mode_set}"])
+    )
+
+
+# ── Main ──────────────────────────────────────────────────────────────────────
+
+def generate_launch_description():
+
+    # ── Launch arguments ──────────────────────────────────────────────────────
+
+    mode_arg = DeclareLaunchArgument(
+        "mode",
+        default_value="indoor",
+        choices=["indoor", "outdoor", "follow"],
+        description=(
+            "Stack mode — indoor: SLAM+Nav2+follow; "
+            "outdoor: GPS nav+follow; "
+            "follow: sensors+UWB+perception+follower only"
+        ),
+    )
+
+    use_sim_time_arg = DeclareLaunchArgument(
+        "use_sim_time",
+        default_value="false",
+        description="Use /clock from rosbag/simulator instead of wall clock",
+    )
+
+    enable_csi_cameras_arg = DeclareLaunchArgument(
+        "enable_csi_cameras",
+        default_value="true",
+        description="Launch 4× IMX219 CSI surround cameras",
+    )
+
+    enable_uwb_arg = DeclareLaunchArgument(
+        "enable_uwb",
+        default_value="true",
+        description="Launch UWB driver (requires MaUWB anchors on USB)",
+    )
+
+    enable_perception_arg = DeclareLaunchArgument(
+        "enable_perception",
+        default_value="true",
+        description="Launch YOLOv8n person detection (TensorRT)",
+    )
+
+    enable_follower_arg = DeclareLaunchArgument(
+        "enable_follower",
+        default_value="true",
+        description="Launch proportional person-follower controller",
+    )
+
+    enable_bridge_arg = DeclareLaunchArgument(
+        "enable_bridge",
+        default_value="true",
+        description="Launch STM32 serial bridge + cmd_vel bridge (disable for sim/rosbag)",
+    )
+
+    enable_rosbridge_arg = DeclareLaunchArgument(
+        "enable_rosbridge",
+        default_value="true",
+        description="Launch rosbridge WebSocket server (port 9090)",
+    )
+
+    follow_distance_arg = DeclareLaunchArgument(
+        "follow_distance",
+        default_value="1.5",
+        description="Person-follower target distance (m)",
+    )
+
+    max_linear_vel_arg = DeclareLaunchArgument(
+        "max_linear_vel",
+        default_value="0.5",
+        description="Max forward velocity cap (m/s) — forwarded to both follower and cmd_vel bridge",
+    )
+
+    uwb_port_a_arg = DeclareLaunchArgument(
+        "uwb_port_a",
+        default_value="/dev/uwb-anchor0",
+        description="UWB anchor-0 serial port (port/left side)",
+    )
+
+    uwb_port_b_arg = DeclareLaunchArgument(
+        "uwb_port_b",
+        default_value="/dev/uwb-anchor1",
+        description="UWB anchor-1 serial port (starboard/right side)",
+    )
+
+    stm32_port_arg = DeclareLaunchArgument(
+        "stm32_port",
+        default_value="/dev/stm32-bridge",
+        description="STM32 USB CDC serial port",
+    )
+
+    # ── Shared substitution handles ───────────────────────────────────────────
+    mode            = LaunchConfiguration("mode")
+    use_sim_time    = LaunchConfiguration("use_sim_time")
+    follow_distance = LaunchConfiguration("follow_distance")
+    max_linear_vel  = LaunchConfiguration("max_linear_vel")
+    uwb_port_a      = LaunchConfiguration("uwb_port_a")
+    uwb_port_b      = LaunchConfiguration("uwb_port_b")
+    stm32_port      = LaunchConfiguration("stm32_port")
+
+    # ── t=0s  Robot description (URDF + TF tree) ──────────────────────────────
+    robot_description = IncludeLaunchDescription(
+        _launch("saltybot_description", "launch", "robot_description.launch.py"),
+        launch_arguments={"use_sim_time": use_sim_time}.items(),
+    )
+
+    # ── t=0s  STM32 bidirectional serial bridge ────────────────────────────────
+    stm32_bridge = GroupAction(
+        condition=IfCondition(LaunchConfiguration("enable_bridge")),
+        actions=[
+            IncludeLaunchDescription(
+                _launch("saltybot_bridge", "launch", "bridge.launch.py"),
+                launch_arguments={
+                    "mode":        "bidirectional",
+                    "serial_port": stm32_port,
+                }.items(),
+            ),
+        ],
+    )
+
+    # ── t=2s  cmd_vel safety bridge (depends on STM32 bridge) ────────────────
+    cmd_vel_bridge = TimerAction(
+        period=2.0,
+        actions=[
+            GroupAction(
+                condition=IfCondition(LaunchConfiguration("enable_bridge")),
+                actions=[
+                    IncludeLaunchDescription(
+                        _launch("saltybot_bridge", "launch", "cmd_vel_bridge.launch.py"),
+                        launch_arguments={
+                            "max_linear_vel": max_linear_vel,
+                        }.items(),
+                    ),
+                ],
+            ),
+        ],
+    )
+
+    # ── t=2s  Sensors: RPLIDAR + RealSense D435i ──────────────────────────────
+    sensors = TimerAction(
+        period=2.0,
+        actions=[
+            IncludeLaunchDescription(
+                _launch("saltybot_bringup", "launch", "sensors.launch.py"),
+            ),
+        ],
+    )
+
+    # ── t=4s  Optional: 4× IMX219 CSI surround cameras ───────────────────────
+    csi_cameras = TimerAction(
+        period=4.0,
+        actions=[
+            GroupAction(
+                condition=IfCondition(LaunchConfiguration("enable_csi_cameras")),
+                actions=[
+                    IncludeLaunchDescription(
+                        _launch("saltybot_cameras", "launch", "csi_cameras.launch.py"),
+                    ),
+                ],
+            ),
+        ],
+    )
+
+    # ── t=4s  UWB driver (independent serial — can start early) ──────────────
+    uwb_driver = TimerAction(
+        period=4.0,
+        actions=[
+            GroupAction(
+                condition=IfCondition(LaunchConfiguration("enable_uwb")),
+                actions=[
+                    IncludeLaunchDescription(
+                        _launch("saltybot_uwb", "launch", "uwb.launch.py"),
+                        launch_arguments={
+                            "port_a": uwb_port_a,
+                            "port_b": uwb_port_b,
+                        }.items(),
+                    ),
+                ],
+            ),
+        ],
+    )
+
+    # ── t=6s  SLAM — RTAB-Map (indoor only; needs sensors up for ~4s) ─────────
+    slam = TimerAction(
+        period=6.0,
+        actions=[
+            GroupAction(
+                condition=_mode_is("indoor"),
+                actions=[
+                    LogInfo(msg="[full_stack] Starting RTAB-Map SLAM (indoor mode)"),
+                    IncludeLaunchDescription(
+                        _launch("saltybot_bringup", "launch", "slam_rtabmap.launch.py"),
+                        launch_arguments={
+                            "use_sim_time": use_sim_time,
+                        }.items(),
+                    ),
+                ],
+            ),
+        ],
+    )
+
+    # ── t=6s  Outdoor navigation (outdoor only; no SLAM) ─────────────────────
+    outdoor_nav = TimerAction(
+        period=6.0,
+        actions=[
+            GroupAction(
+                condition=_mode_is("outdoor"),
+                actions=[
+                    LogInfo(msg="[full_stack] Starting outdoor GPS navigation"),
+                    IncludeLaunchDescription(
+                        _launch("saltybot_outdoor", "launch", "outdoor_nav.launch.py"),
+                        launch_arguments={
+                            "use_sim_time": use_sim_time,
+                        }.items(),
+                    ),
+                ],
+            ),
+        ],
+    )
+
+    # ── t=6s  Person detection (needs RealSense up for ~4s) ──────────────────
+    perception = TimerAction(
+        period=6.0,
+        actions=[
+            GroupAction(
+                condition=IfCondition(LaunchConfiguration("enable_perception")),
+                actions=[
+                    LogInfo(msg="[full_stack] Starting YOLOv8n person detection"),
+                    IncludeLaunchDescription(
+                        _launch("saltybot_perception", "launch", "person_detection.launch.py"),
+                        launch_arguments={
+                            "use_sim_time": use_sim_time,
+                        }.items(),
+                    ),
+                ],
+            ),
+        ],
+    )
+
+    # ── t=9s  Person follower (needs perception + UWB; ~3s after both start) ─
+    follower = TimerAction(
+        period=9.0,
+        actions=[
+            GroupAction(
+                condition=IfCondition(LaunchConfiguration("enable_follower")),
+                actions=[
+                    LogInfo(msg="[full_stack] Starting person follower"),
+                    IncludeLaunchDescription(
+                        _launch("saltybot_follower", "launch", "person_follower.launch.py"),
+                        launch_arguments={
+                            "follow_distance": follow_distance,
+                            "max_linear_vel":  max_linear_vel,
+                        }.items(),
+                    ),
+                ],
+            ),
+        ],
+    )
+
+    # ── t=14s  Nav2 (indoor only; SLAM needs ~8s to build initial map) ────────
+    nav2 = TimerAction(
+        period=14.0,
+        actions=[
+            GroupAction(
+                condition=_mode_is("indoor"),
+                actions=[
+                    LogInfo(msg="[full_stack] Starting Nav2 navigation stack"),
+                    IncludeLaunchDescription(
+                        _launch("saltybot_bringup", "launch", "nav2.launch.py"),
+                    ),
+                ],
+            ),
+        ],
+    )
+
+    # ── t=17s  rosbridge WebSocket (last — all topics must be alive) ──────────
+    rosbridge = TimerAction(
+        period=17.0,
+        actions=[
+            GroupAction(
+                condition=IfCondition(LaunchConfiguration("enable_rosbridge")),
+                actions=[
+                    LogInfo(msg="[full_stack] Starting rosbridge (ws://0.0.0.0:9090)"),
+                    IncludeLaunchDescription(
+                        _launch("saltybot_bringup", "launch", "rosbridge.launch.py"),
+                    ),
+                ],
+            ),
+        ],
+    )
+
+    # ── Startup banner ────────────────────────────────────────────────────────
+    banner = LogInfo(
+        msg=["[full_stack] SaltyBot bringup starting — mode=", mode,
+             "  sim_time=", use_sim_time]
+    )
+
+    # ── Assemble ──────────────────────────────────────────────────────────────
+    return LaunchDescription([
+        # Arguments
+        mode_arg,
+        use_sim_time_arg,
+        enable_csi_cameras_arg,
+        enable_uwb_arg,
+        enable_perception_arg,
+        enable_follower_arg,
+        enable_bridge_arg,
+        enable_rosbridge_arg,
+        follow_distance_arg,
+        max_linear_vel_arg,
+        uwb_port_a_arg,
+        uwb_port_b_arg,
+        stm32_port_arg,
+
+        # Startup banner
+        banner,
+
+        # t=0s
+        robot_description,
+        stm32_bridge,
+
+        # t=2s
+        sensors,
+        cmd_vel_bridge,
+
+        # t=4s
+        csi_cameras,
+        uwb_driver,
+
+        # t=6s
+        slam,
+        outdoor_nav,
+        perception,
+
+        # t=9s
+        follower,
+
+        # t=14s
+        nav2,
+
+        # t=17s
+        rosbridge,
+    ])

jetson/ros2_ws/src/saltybot_bringup/package.xml

@@ -3,8 +3,8 @@
 <package format="3">
   <name>saltybot_bringup</name>
   <version>0.1.0</version>
-  <description>SaltyBot launch files — RealSense D435i + RPLIDAR A1M8 sensor bringup and SLAM integration</description>
-  <maintainer email="sl-perception@saltylab.local">sl-perception</maintainer>
+  <description>SaltyBot launch files — full autonomous stack bringup (sensors, SLAM, Nav2, UWB, perception, follower)</description>
+  <maintainer email="sl-jetson@saltylab.local">sl-jetson</maintainer>
   <license>MIT</license>
 
   <exec_depend>rplidar_ros</exec_depend>
@@ -18,6 +18,14 @@
   <exec_depend>rosbridge_server</exec_depend>
   <exec_depend>image_transport</exec_depend>
   <exec_depend>image_transport_plugins</exec_depend>
+  <!-- SaltyBot packages included by full_stack.launch.py -->
+  <exec_depend>saltybot_bridge</exec_depend>
+  <exec_depend>saltybot_cameras</exec_depend>
+  <exec_depend>saltybot_description</exec_depend>
+  <exec_depend>saltybot_follower</exec_depend>
+  <exec_depend>saltybot_outdoor</exec_depend>
+  <exec_depend>saltybot_perception</exec_depend>
+  <exec_depend>saltybot_uwb</exec_depend>
 
   <buildtool_depend>ament_python</buildtool_depend>
 

jetson/ros2_ws/src/saltybot_outdoor/config/ekf_outdoor.yaml

@@ -0,0 +1,92 @@
+# ekf_outdoor.yaml — robot_localization EKF config for outdoor GPS navigation
+#
+# Two EKF instances + navsat_transform_node:
+#
+#   ekf_filter_node_odom  — local EKF: wheel odom + IMU → /odometry/local (odom frame)
+#   ekf_filter_node_map   — global EKF: /odometry/local + GPS odometry → /odometry/global (map frame)
+#   navsat_transform_node — converts /gps/fix + /imu/data → /odometry/gps (map-frame odometry)
+#
+# Frame hierarchy:
+#   map ← (global EKF) ← odom ← (local EKF) ← base_link
+#
+# Hardware:
+#   IMU:  RealSense D435i BMI055 → /imu/data
+#   GPS:  SIM7600X cellular     → /gps/fix  (±2.5 m CEP)
+#   Odom: STM32 wheel encoders  → /odom
+#   RTK:  ZED-F9P (optional)    → /gps/fix  (±2 cm CEP when use_rtk: true)
+
+# ── Local EKF: fuses wheel odometry + IMU in odom frame ──────────────────────
+ekf_filter_node_odom:
+  ros__parameters:
+    frequency:               30.0
+    sensor_timeout:          0.1
+    two_d_mode:              true
+    publish_tf:              true
+    map_frame:               map
+    odom_frame:              odom
+    base_link_frame:         base_link
+    world_frame:             odom
+
+    odom0:                   /odom
+    odom0_config: [true,  true,  false,
+                   false, false, false,
+                   true,  true,  false,
+                   false, false, true,
+                   false, false, false]
+    odom0_differential:      false
+    odom0_relative:          false
+    odom0_queue_size:        5
+
+    imu0:                    /imu/data
+    imu0_config: [false, false, false,
+                  true,  true,  true,
+                  false, false, false,
+                  true,  true,  true,
+                  true,  true,  false]
+    imu0_differential:       false
+    imu0_relative:           false
+    imu0_remove_gravitational_acceleration: true
+    imu0_queue_size:         10
+
+# ── Global EKF: fuses local odometry + GPS odometry in map frame ──────────────
+ekf_filter_node_map:
+  ros__parameters:
+    frequency:               15.0
+    sensor_timeout:          0.5
+    two_d_mode:              true
+    publish_tf:              true
+    map_frame:               map
+    odom_frame:              odom
+    base_link_frame:         base_link
+    world_frame:             map
+
+    odom0:                   /odometry/local
+    odom0_config: [false, false, false,
+                   false, false, false,
+                   true,  true,  false,
+                   false, false, true,
+                   false, false, false]
+    odom0_differential:      false
+    odom0_queue_size:        5
+
+    odom1:                   /odometry/gps
+    odom1_config: [true,  true,  false,
+                   false, false, false,
+                   false, false, false,
+                   false, false, false,
+                   false, false, false]
+    odom1_differential:      false
+    odom1_queue_size:        5
+
+# ── navsat_transform_node — GPS NavSatFix → map-frame Odometry ────────────────
+navsat_transform:
+  ros__parameters:
+    frequency:                   10.0
+    delay:                       3.0
+    magnetic_declination_radians: 0.0
+    yaw_offset:                  0.0
+    zero_altitude:               true
+    broadcast_utm_transform:     false
+    publish_filtered_gps:        false
+    use_odometry_yaw:            false
+    wait_for_datum:              false

jetson/ros2_ws/src/saltybot_outdoor/config/geofence_vertices.yaml

@@ -0,0 +1,35 @@
+# geofence_vertices.yaml — GPS polygon safety boundary for outdoor navigation
+#
+# Format: fence_vertices is a flat list [lat0, lon0, lat1, lon1, ..., latN, lonN]
+# Minimum 3 vertex pairs (6 values). Leave empty [] to disable geofence.
+#
+# ── How to set your fence ────────────────────────────────────────────────────
+# 1. Go to https://geojson.io and mark your safe operating area corners
+# 2. Replace the example values below with real coordinates
+# 3. Reload at runtime: ros2 service call /outdoor/reload_fence std_srvs/srv/Trigger '{}'
+#
+# ── Unit conversions ─────────────────────────────────────────────────────────
+#   d_lat_deg = d_metres / 111320
+#   d_lon_deg = d_metres / (111320 * cos(lat_radians))
+#
+geofence:
+  ros__parameters:
+    # Empty = geofence inactive (WARNING: no safety boundary without a fence)
+    fence_vertices: []
+    check_rate_hz:  2.0
+    stop_on_exit:   true
+    map_frame:      "map"
+
+# ── EXAMPLE (uncomment and edit with real coordinates) ───────────────────────
+# geofence:
+#   ros__parameters:
+#     # SW → SE → NE → NW corners of a ~100m × 80m rectangle
+#     fence_vertices:
+#       - 37.774900   # SW lat
+#       - -122.419400 # SW lon
+#       - 37.774900   # SE lat
+#       - -122.418500 # SE lon
+#       - 37.775800   # NE lat
+#       - -122.418500 # NE lon
+#       - 37.775800   # NW lat
+#       - -122.419400 # NW lon

jetson/ros2_ws/src/saltybot_outdoor/config/outdoor_nav_params.yaml

@@ -0,0 +1,98 @@
+# outdoor_nav_params.yaml — Outdoor navigation configuration for SaltyBot
+#
+# Hardware: Jetson Orin Nano Super / SIM7600X cellular GPS (±2.5 m CEP)
+# RTK upgrade: u-blox ZED-F9P → ±2 cm CEP (set use_rtk: true when installed)
+#
+# ── GPS quality notes ────────────────────────────────────────────────────────
+# SIM7600X reports STATUS_FIX (0) in open sky, STATUS_NO_FIX (-1) indoors.
+# RTK ZED-F9P reports STATUS_GBAS_FIX (2) when corrections received.
+# Goal tolerance automatically tightens from 2.0m (cellular) to 0.3m (RTK).
+#
+# ── RTK upgrade procedure ────────────────────────────────────────────────────
+# 1. Connect ZED-F9P to /dev/ttyTHS0 (Orin 40-pin UART, pins 8/10)
+# 2. Set NTRIP credentials in rtk_gps.launch.py
+# 3. Run: ros2 launch saltybot_outdoor rtk_gps.launch.py
+# 4. Verify: ros2 topic echo /gps/fix | grep status
+#    → status.status == 2 (STATUS_GBAS_FIX) = RTK fixed
+#
+# References:
+#   SparkFun RTK Express: https://docs.sparkfun.com/SparkFun_RTK_Everywhere_Firmware/
+#   NTRIP caster list: https://rtk2go.com/sample-map/
+# ─────────────────────────────────────────────────────────────────────────────
+
+osm_router:
+  ros__parameters:
+    overpass_url:       "https://overpass-api.de/api/interpreter"
+    query_radius_m:     1500.0      # fetch OSM ways within this radius of midpoint
+    simplify_eps_m:     5.0         # Douglas–Peucker waypoint spacing (metres)
+    cache_dir:          "/data/osm_cache"
+    use_cache:          true
+    map_frame:          "map"
+    # Default goal — override at launch or via parameter set:
+    #   ros2 param set /osm_router goal_lat 48.8566
+    #   ros2 param set /osm_router goal_lon 2.3522
+    goal_lat:           0.0
+    goal_lon:           0.0
+
+gps_waypoint_follower:
+  ros__parameters:
+    map_frame:            "map"
+    min_fix_status:       0         # 0=STATUS_FIX; -1=NO_FIX; 2=RTK_FIXED
+    # Goal tolerance for SIM7600X (±2.5m CEP) — auto-tightens with RTK
+    goal_tolerance_xy:    2.0       # metres (outdoor vs 0.25m indoor)
+    goal_tolerance_yaw:   3.14159   # radians — don't constrain heading outdoors
+    nav_timeout_s:        300.0     # 5 min max per navigate_through_poses call
+    waypoint_spacing_m:   5.0       # skip waypoints closer than this
+
+geofence:
+  ros__parameters:
+    check_rate_hz:  2.0
+    stop_on_exit:   true
+    # fence_vertices: flat list of lat,lon pairs forming the boundary polygon.
+    # Leave empty to disable geofence (WARNING: no safety boundary).
+    # Example — 100m × 100m test square (replace with real boundary):
+    fence_vertices: []
+    map_frame: "map"
+
+# ── Outdoor Nav2 parameter overrides ────────────────────────────────────────
+# These supplement jetson/config/nav2_params.yaml for outdoor operation.
+# Apply by passing this file as an additional params_file to nav2.launch.py.
+#
+# Key differences from indoor config:
+#   - No static_layer (no SLAM map — GPS provides global position only)
+#   - Wider inflation radius (outdoor = wider obstacles / kerbs)
+#   - Higher max velocity (clear sidewalks vs cluttered indoor)
+#   - GPS costmap uses wider observation sources
+# ─────────────────────────────────────────────────────────────────────────────
+
+# Outdoor controller overrides
+controller_server:
+  ros__parameters:
+    FollowPath:
+      max_vel_x:   1.5      # m/s (indoor: 1.0)
+      max_speed_xy: 1.5
+      sim_time:    2.0      # seconds lookahead (longer for faster speeds)
+      # Larger goal tolerance at waypoints (GPS ±2.5m)
+    general_goal_checker:
+      xy_goal_tolerance:  2.0    # metres (indoor: 0.25)
+      yaw_goal_tolerance: 3.14   # don't constrain heading at GPS waypoints
+
+# Outdoor local costmap overrides
+local_costmap:
+  local_costmap:
+    ros__parameters:
+      width:  5        # metres (wider window for outdoor speeds)
+      height: 5
+      inflation_layer:
+        inflation_radius: 0.50   # metres (indoor: 0.55, similar but explicit)
+
+# Outdoor global costmap overrides
+# Key: remove static_layer (no SLAM map), keep obstacle layers
+global_costmap:
+  global_costmap:
+    ros__parameters:
+      plugins: ["obstacle_layer", "inflation_layer"]  # no static_layer outdoors
+      inflation_layer:
+        inflation_radius: 0.50
+      obstacle_layer:
+        observation_sources: scan surround_cameras

jetson/ros2_ws/src/saltybot_outdoor/launch/outdoor_nav.launch.py

@@ -0,0 +1,122 @@
+"""
+outdoor_nav.launch.py — Full outdoor navigation stack for SaltyBot
+
+Services started:
+  osm_router_node         — Overpass API OSM routing → /outdoor/waypoints
+  gps_waypoint_follower   — /outdoor/waypoints → Nav2 navigate_through_poses
+  geofence_node           — GPS polygon safety boundary
+  navsat_transform_node   — robot_localization GPS→map projection (EKF)
+  ekf_filter_node_odom    — local EKF (odom frame)
+  ekf_filter_node_map     — global EKF (map frame, GPS-fused)
+
+Nav2 is NOT started here — it must already be running (saltybot-nav2 container).
+
+Outdoor mode: uses GPS for global localisation instead of RTAB-Map.
+Indoor mode:  use slam_rtabmap.launch.py instead (RTAB-Map provides map→odom).
+
+Arguments:
+  use_rtk         (default false) — set true when ZED-F9P RTK module installed
+  fence_active    (default true)  — enable geofence safety boundary
+  goal_lat        (default 0.0)   — navigation goal latitude
+  goal_lon        (default 0.0)   — navigation goal longitude
+"""
+
+import os
+from ament_index_python.packages import get_package_share_directory
+
+from launch import LaunchDescription
+from launch.actions import DeclareLaunchArgument
+from launch.substitutions import LaunchConfiguration
+from launch_ros.actions import Node
+
+
+def generate_launch_description():
+    pkg_dir = get_package_share_directory('saltybot_outdoor')
+    params_file    = os.path.join(pkg_dir, 'config', 'outdoor_nav_params.yaml')
+    ekf_file       = os.path.join(pkg_dir, 'config', 'ekf_outdoor.yaml')
+    geofence_file  = os.path.join(pkg_dir, 'config', 'geofence_vertices.yaml')
+
+    args = [
+        DeclareLaunchArgument('use_rtk',      default_value='false'),
+        DeclareLaunchArgument('fence_active', default_value='true'),
+        DeclareLaunchArgument('goal_lat',     default_value='0.0'),
+        DeclareLaunchArgument('goal_lon',     default_value='0.0'),
+    ]
+
+    # ── robot_localization: local EKF (odom frame) ───────────────────────────
+    ekf_local = Node(
+        package='robot_localization',
+        executable='ekf_node',
+        name='ekf_filter_node_odom',
+        output='screen',
+        parameters=[ekf_file, {'use_sim_time': False}],
+        remappings=[('odometry/filtered', '/odometry/local')],
+    )
+
+    # ── robot_localization: global EKF (map frame, GPS-fused) ────────────────
+    ekf_global = Node(
+        package='robot_localization',
+        executable='ekf_node',
+        name='ekf_filter_node_map',
+        output='screen',
+        parameters=[ekf_file, {'use_sim_time': False}],
+        remappings=[('odometry/filtered', '/odometry/global')],
+    )
+
+    # ── navsat_transform_node — GPS (NavSatFix) → map-frame Odometry ─────────
+    navsat = Node(
+        package='robot_localization',
+        executable='navsat_transform_node',
+        name='navsat_transform',
+        output='screen',
+        parameters=[ekf_file, {'use_sim_time': False}],
+        remappings=[
+            ('imu/data',       '/imu/data'),
+            ('gps/fix',        '/gps/fix'),
+            ('odometry/filtered', '/odometry/global'),
+            ('odometry/gps',   '/odometry/gps'),
+        ],
+    )
+
+    # ── OSM router ───────────────────────────────────────────────────────────
+    osm_router = Node(
+        package='saltybot_outdoor',
+        executable='osm_router_node',
+        name='osm_router',
+        output='screen',
+        parameters=[
+            params_file,
+            {
+                'goal_lat': LaunchConfiguration('goal_lat'),
+                'goal_lon': LaunchConfiguration('goal_lon'),
+            },
+        ],
+    )
+
+    # ── GPS waypoint follower ─────────────────────────────────────────────────
+    gps_follower = Node(
+        package='saltybot_outdoor',
+        executable='gps_waypoint_follower',
+        name='gps_waypoint_follower',
+        output='screen',
+        parameters=[params_file],
+    )
+
+    # ── Geofence ──────────────────────────────────────────────────────────────
+    geofence = Node(
+        package='saltybot_outdoor',
+        executable='geofence_node',
+        name='geofence',
+        output='screen',
+        parameters=[geofence_file],
+    )
+
+    return LaunchDescription([
+        *args,
+        ekf_local,
+        ekf_global,
+        navsat,
+        osm_router,
+        gps_follower,
+        geofence,
+    ])

jetson/ros2_ws/src/saltybot_outdoor/package.xml

@@ -0,0 +1,30 @@
+<?xml version="1.0"?>
+<?xml-model href="http://download.ros.org/schema/package_format3.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?>
+<package format="3">
+  <name>saltybot_outdoor</name>
+  <version>0.1.0</version>
+  <description>Outdoor navigation for SaltyBot — OSM routing, GPS waypoint following, geofence</description>
+  <maintainer email="seb@saltylab.io">seb</maintainer>
+  <license>MIT</license>
+
+  <buildtool_depend>ament_python</buildtool_depend>
+
+  <depend>rclpy</depend>
+  <depend>sensor_msgs</depend>
+  <depend>geometry_msgs</depend>
+  <depend>nav_msgs</depend>
+  <depend>std_msgs</depend>
+  <depend>std_srvs</depend>
+  <depend>nav2_msgs</depend>
+
+  <exec_depend>robot_localization</exec_depend>
+  <exec_depend>nav2_bringup</exec_depend>
+
+  <test_depend>ament_copyright</test_depend>
+  <test_depend>ament_flake8</test_depend>
+  <test_depend>ament_pep257</test_depend>
+
+  <export>
+    <build_type>ament_python</build_type>
+  </export>
+</package>

jetson/ros2_ws/src/saltybot_outdoor/saltybot_outdoor/geofence_node.py

@@ -0,0 +1,197 @@
+"""
+geofence_node — GPS polygon safety boundary for outdoor navigation
+
+Monitors /gps/fix and checks the robot's position against a configurable
+polygon of GPS vertices. If the robot exits the fence OR a requested waypoint
+lies outside the fence, this node:
+  1. Publishes /outdoor/abort True → gps_waypoint_follower cancels Nav2
+  2. Publishes /cmd_vel zero twist (emergency stop)
+  3. Publishes /outdoor/fence_violation with details
+
+The fence polygon is defined in geofence_vertices.yaml as a list of
+{lat, lon} pairs forming a closed polygon (first = last not required).
+Point-in-polygon test uses the ray-casting algorithm.
+
+Topics subscribed:
+  /gps/fix               sensor_msgs/NavSatFix
+  /outdoor/waypoints     geometry_msgs/PoseArray  — pre-navigation check
+
+Topics published:
+  /outdoor/abort         std_msgs/Bool            — True when fence violated
+  /outdoor/fence_status  std_msgs/String          — 'inside' | 'outside:<lat>,<lon>'
+  /cmd_vel               geometry_msgs/Twist      — zero-velocity on violation
+
+Services:
+  /outdoor/reload_fence  std_srvs/Trigger         — re-read geofence_vertices.yaml
+"""
+
+import math
+from typing import Optional
+
+import rclpy
+from rclpy.node import Node
+from rclpy.qos import QoSProfile, ReliabilityPolicy, HistoryPolicy
+
+from sensor_msgs.msg import NavSatFix
+from geometry_msgs.msg import PoseArray, Twist
+from std_msgs.msg import Bool, String
+from std_srvs.srv import Trigger
+
+
+def _point_in_polygon(lat: float, lon: float, polygon: list) -> bool:
+    """Ray-casting point-in-polygon test. polygon = [(lat, lon), ...]."""
+    n = len(polygon)
+    inside = False
+    j = n - 1
+    for i in range(n):
+        xi, yi = polygon[i]
+        xj, yj = polygon[j]
+        if ((yi > lon) != (yj > lon)) and (lat < (xj - xi) * (lon - yi) / (yj - yi) + xi):
+            inside = not inside
+        j = i
+    return inside
+
+
+def _polygon_area_m2(polygon: list) -> float:
+    """Approximate polygon area in m² using shoelace on flat-earth coords."""
+    if len(polygon) < 3:
+        return 0.0
+    lat0, lon0 = polygon[0]
+    cos0 = math.cos(math.radians(lat0))
+    pts = [
+        ((lat - lat0) * 111_320.0, (lon - lon0) * 111_320.0 * cos0)
+        for lat, lon in polygon
+    ]
+    n = len(pts)
+    area = 0.0
+    for i in range(n):
+        j = (i + 1) % n
+        area += pts[i][0] * pts[j][1]
+        area -= pts[j][0] * pts[i][1]
+    return abs(area) / 2.0
+
+
+class GeofenceNode(Node):
+
+    def __init__(self):
+        super().__init__('geofence')
+
+        self.declare_parameter('fence_vertices',  [])        # flat list: lat0,lon0,lat1,lon1,...
+        self.declare_parameter('check_rate_hz',   2.0)
+        self.declare_parameter('stop_on_exit',    True)      # publish zero /cmd_vel
+        self.declare_parameter('map_frame',       'map')
+
+        self._polygon: list[tuple[float, float]] = []
+        self._fix:     Optional[NavSatFix]        = None
+        self._violated = False
+
+        self._load_fence()
+
+        # ── Subscriptions ────────────────────────────────────────────────────
+        self.create_subscription(NavSatFix, '/gps/fix',           self._fix_cb,  10)
+        self.create_subscription(PoseArray, '/outdoor/waypoints', self._wps_cb,  10)
+
+        # ── Publishers ───────────────────────────────────────────────────────
+        self._abort_pub  = self.create_publisher(Bool,   '/outdoor/abort',        10)
+        self._status_pub = self.create_publisher(String, '/outdoor/fence_status', 10)
+        self._vel_pub    = self.create_publisher(Twist,  '/cmd_vel',              10)
+
+        # ── Service ──────────────────────────────────────────────────────────
+        self.create_service(Trigger, '/outdoor/reload_fence', self._reload_cb)
+
+        rate = self.get_parameter('check_rate_hz').value
+        self.create_timer(1.0 / rate, self._check)
+
+        area = _polygon_area_m2(self._polygon) if self._polygon else 0.0
+        self.get_logger().info(
+            f'geofence: {len(self._polygon)}-vertex polygon, area≈{area:.0f} m²'
+        )
+
+    # ── Callbacks ─────────────────────────────────────────────────────────────
+
+    def _fix_cb(self, msg: NavSatFix) -> None:
+        self._fix = msg
+
+    def _wps_cb(self, msg: PoseArray) -> None:
+        """Pre-check: warn if any map-frame waypoint is suspiciously far out."""
+        # In V1 we can't easily reverse-project map→GPS here without TF/EKF,
+        # so we just log the waypoint count and rely on the robot fix check.
+        self.get_logger().info(
+            f'geofence: {len(msg.poses)} waypoints received (pre-flight GPS check pending)'
+        )
+
+    def _reload_cb(self, _req, response):
+        self._load_fence()
+        response.success = True
+        response.message = f'Fence reloaded: {len(self._polygon)} vertices'
+        return response
+
+    # ── Fence check ───────────────────────────────────────────────────────────
+
+    def _check(self) -> None:
+        if not self._polygon:
+            self._pub_status('no_fence_configured')
+            return
+        if self._fix is None:
+            self._pub_status('no_gps')
+            return
+        if self._fix.status.status < 0:
+            return   # no fix — don't trigger on bad data
+
+        lat, lon = self._fix.latitude, self._fix.longitude
+        inside = _point_in_polygon(lat, lon, self._polygon)
+
+        if inside:
+            self._violated = False
+            self._pub_status('inside')
+        else:
+            if not self._violated:
+                self.get_logger().warn(
+                    f'GEOFENCE VIOLATION: robot at ({lat:.6f}, {lon:.6f}) is outside fence'
+                )
+                self._violated = True
+
+            self._pub_status(f'outside:{lat:.6f},{lon:.6f}')
+
+            # Publish abort
+            abort = Bool()
+            abort.data = True
+            self._abort_pub.publish(abort)
+
+            # Emergency stop
+            if self.get_parameter('stop_on_exit').value:
+                self._vel_pub.publish(Twist())   # zero twist = stop
+
+    # ── Helpers ───────────────────────────────────────────────────────────────
+
+    def _load_fence(self) -> None:
+        """Parse fence_vertices parameter: flat [lat0, lon0, lat1, lon1, ...]."""
+        raw = self.get_parameter('fence_vertices').value
+        if not raw or len(raw) < 6:
+            self._polygon = []
+            self.get_logger().warn('geofence: no valid fence_vertices — geofence inactive')
+            return
+        pairs = list(raw)
+        self._polygon = [(pairs[i], pairs[i + 1]) for i in range(0, len(pairs) - 1, 2)]
+        self.get_logger().info(f'geofence: loaded {len(self._polygon)}-vertex polygon')
+
+    def _pub_status(self, s: str) -> None:
+        msg = String()
+        msg.data = s
+        self._status_pub.publish(msg)
+
+
+def main(args=None):
+    rclpy.init(args=args)
+    node = GeofenceNode()
+    try:
+        rclpy.spin(node)
+    except KeyboardInterrupt:
+        pass
+    finally:
+        node.destroy_node()
+        rclpy.try_shutdown()
+
+
+if __name__ == '__main__':
+    main()

jetson/ros2_ws/src/saltybot_outdoor/saltybot_outdoor/gps_waypoint_follower_node.py

@@ -0,0 +1,287 @@
+"""
+gps_waypoint_follower_node — GPS-to-Nav2 waypoint bridge for outdoor navigation
+
+Subscribes to the OSM router's waypoint output (/outdoor/waypoints) and the
+robot's GPS fix (/gps/fix), converts each waypoint to map-frame via
+robot_localization's navsat_transform_node, then sends the full list to Nav2's
+navigate_through_poses action server.
+
+GPS quality handling:
+  SIM7600X cellular GPS: ±2.5 m CEP — uses wider goal tolerances (2 m)
+  RTK upgrade (ZED-F9P): ±0.02 m CEP — tolerances tighten automatically
+
+GPS status thresholds (sensor_msgs/NavSatStatus):
+  STATUS_NO_FIX    (-1) → reject all goals, log error
+  STATUS_FIX       (0)  → standard GPS, use but warn
+  STATUS_SBAS_FIX  (1)  → SBAS-corrected, OK
+  STATUS_GBAS_FIX  (2)  → RTK fixed, best quality, tighten tolerance
+
+Topics subscribed:
+  /gps/fix              sensor_msgs/NavSatFix
+  /outdoor/waypoints    geometry_msgs/PoseArray (from osm_router_node, map frame)
+  /outdoor/abort        std_msgs/Bool           (external stop signal)
+
+Topics published:
+  /outdoor/gps_status   std_msgs/String   — current GPS quality description
+  /outdoor/nav_status   std_msgs/String   — navigation state machine status
+
+Actions called:
+  /navigate_through_poses  nav2_msgs/action/NavigateThroughPoses
+
+Services:
+  /outdoor/start_navigation  std_srvs/Trigger — begin executing /outdoor/waypoints
+  /outdoor/stop_navigation   std_srvs/Trigger — cancel in-progress navigation
+"""
+
+import math
+from typing import Optional
+
+import rclpy
+from rclpy.node import Node
+from rclpy.action import ActionClient
+from rclpy.callback_groups import ReentrantCallbackGroup
+from rclpy.executors import MultiThreadedExecutor
+
+from sensor_msgs.msg import NavSatFix, NavSatStatus
+from geometry_msgs.msg import PoseArray, PoseStamped
+from std_msgs.msg import String, Bool
+from std_srvs.srv import Trigger
+
+from nav2_msgs.action import NavigateThroughPoses
+
+
+# GPS fix quality thresholds
+_MIN_FIX_STATUS = NavSatStatus.STATUS_FIX   # reject STATUS_NO_FIX (-1)
+_RTK_FIX_STATUS = NavSatStatus.STATUS_GBAS_FIX
+
+# Goal tolerance (metres) by GPS quality
+_TOLERANCE_STANDARD_GPS = 2.0    # SIM7600X ±2.5 m CEP
+_TOLERANCE_RTK          = 0.30   # ZED-F9P ±2 cm RTK
+
+
+class GpsWaypointFollowerNode(Node):
+
+    def __init__(self):
+        super().__init__('gps_waypoint_follower')
+
+        self.declare_parameter('map_frame',           'map')
+        self.declare_parameter('min_fix_status',      _MIN_FIX_STATUS)
+        self.declare_parameter('goal_tolerance_xy',   _TOLERANCE_STANDARD_GPS)
+        self.declare_parameter('goal_tolerance_yaw',  3.14)    # don't care about heading
+        self.declare_parameter('nav_timeout_s',       300.0)   # 5 min per waypoint batch
+        self.declare_parameter('waypoint_spacing_m',  5.0)     # skip closer waypoints
+
+        self._fix:       Optional[NavSatFix]  = None
+        self._waypoints: Optional[PoseArray]  = None
+        self._nav_active = False
+        self._cb_group   = ReentrantCallbackGroup()
+
+        # ── Subscriptions ────────────────────────────────────────────────────
+        self.create_subscription(NavSatFix,  '/gps/fix',           self._fix_cb,       10)
+        self.create_subscription(PoseArray,  '/outdoor/waypoints', self._waypoints_cb, 10)
+        self.create_subscription(Bool,       '/outdoor/abort',     self._abort_cb,     10)
+
+        # ── Publishers ───────────────────────────────────────────────────────
+        self._gps_status_pub = self.create_publisher(String, '/outdoor/gps_status', 10)
+        self._nav_status_pub = self.create_publisher(String, '/outdoor/nav_status',  10)
+
+        # ── Services ─────────────────────────────────────────────────────────
+        self.create_service(Trigger, '/outdoor/start_navigation', self._start_cb,
+                            callback_group=self._cb_group)
+        self.create_service(Trigger, '/outdoor/stop_navigation',  self._stop_cb,
+                            callback_group=self._cb_group)
+
+        # ── Nav2 action client ───────────────────────────────────────────────
+        self._nav_client = ActionClient(
+            self, NavigateThroughPoses, '/navigate_through_poses',
+            callback_group=self._cb_group,
+        )
+
+        # ── Status timer ─────────────────────────────────────────────────────
+        self.create_timer(2.0, self._publish_gps_status)
+
+        self._nav_goal_handle = None
+        self._publish_nav_status('idle')
+        self.get_logger().info('gps_waypoint_follower: ready. Call /outdoor/start_navigation.')
+
+    # ── Callbacks ─────────────────────────────────────────────────────────────
+
+    def _fix_cb(self, msg: NavSatFix) -> None:
+        self._fix = msg
+
+    def _waypoints_cb(self, msg: PoseArray) -> None:
+        self._waypoints = msg
+        self.get_logger().info(f'Received {len(msg.poses)} outdoor waypoints')
+
+    def _abort_cb(self, msg: Bool) -> None:
+        if msg.data:
+            self._cancel_navigation('abort signal received')
+
+    def _start_cb(self, _req, response):
+        if self._nav_active:
+            response.success = False
+            response.message = 'Navigation already active'
+            return response
+
+        if self._fix is None:
+            response.success = False
+            response.message = 'No GPS fix'
+            return response
+
+        fix_status = self._fix.status.status
+        min_status = self.get_parameter('min_fix_status').value
+        if fix_status < min_status:
+            response.success = False
+            response.message = f'GPS quality too low: status={fix_status}'
+            return response
+
+        if self._waypoints is None or len(self._waypoints.poses) == 0:
+            response.success = False
+            response.message = 'No waypoints loaded — call /outdoor/plan_route first'
+            return response
+
+        # Send waypoints to Nav2 asynchronously
+        self.create_timer(0.1, self._send_nav_goal, callback_group=self._cb_group)
+        response.success = True
+        response.message = f'Starting navigation with {len(self._waypoints.poses)} waypoints'
+        return response
+
+    def _stop_cb(self, _req, response):
+        self._cancel_navigation('stop requested')
+        response.success = True
+        response.message = 'Navigation cancelled'
+        return response
+
+    # ── Navigation ────────────────────────────────────────────────────────────
+
+    def _send_nav_goal(self) -> None:
+        """One-shot timer callback: send waypoints to Nav2."""
+        # Cancel the timer that called us
+        self.destroy_timer(list(self.timers)[-1])
+
+        if not self._nav_client.wait_for_server(timeout_sec=5.0):
+            self.get_logger().error('Nav2 navigate_through_poses action not available')
+            self._publish_nav_status('error:nav2_unavailable')
+            return
+
+        # Adjust goal tolerance by GPS quality
+        fix_status = self._fix.status.status if self._fix else _MIN_FIX_STATUS
+        if fix_status >= _RTK_FIX_STATUS:
+            tol = _TOLERANCE_RTK
+            self.get_logger().info('RTK fix detected — using tight tolerance (0.30 m)')
+        else:
+            tol = self.get_parameter('goal_tolerance_xy').value
+            self.get_logger().info(f'Standard GPS — tolerance = {tol:.1f} m')
+
+        # Build goal: PoseStamped list from PoseArray
+        goal = NavigateThroughPoses.Goal()
+        frame = self.get_parameter('map_frame').value
+        now   = self.get_clock().now().to_msg()
+
+        poses = self._filter_waypoints(self._waypoints.poses)
+        for pose in poses:
+            ps = PoseStamped()
+            ps.header.stamp    = now
+            ps.header.frame_id = frame
+            ps.pose = pose
+            goal.poses.append(ps)
+
+        self.get_logger().info(f'Sending {len(goal.poses)} waypoints to Nav2')
+        self._publish_nav_status(f'navigating:{len(goal.poses)}_waypoints')
+        self._nav_active = True
+
+        send_future = self._nav_client.send_goal_async(
+            goal,
+            feedback_callback=self._nav_feedback_cb,
+        )
+        send_future.add_done_callback(self._nav_goal_response_cb)
+
+    def _nav_goal_response_cb(self, future) -> None:
+        self._nav_goal_handle = future.result()
+        if not self._nav_goal_handle.accepted:
+            self.get_logger().error('Nav2 rejected navigation goal')
+            self._nav_active = False
+            self._publish_nav_status('error:goal_rejected')
+            return
+        result_future = self._nav_goal_handle.get_result_async()
+        result_future.add_done_callback(self._nav_result_cb)
+
+    def _nav_feedback_cb(self, feedback) -> None:
+        fb = feedback.feedback
+        remaining = getattr(fb, 'number_of_poses_remaining', '?')
+        self.get_logger().info(
+            f'Nav2 feedback: {remaining} waypoints remaining',
+            throttle_duration_sec=10.0,
+        )
+
+    def _nav_result_cb(self, future) -> None:
+        self._nav_active = False
+        result = future.result()
+        if result.status == 4:   # SUCCEEDED
+            self.get_logger().info('Outdoor navigation completed successfully')
+            self._publish_nav_status('completed')
+        else:
+            self.get_logger().warn(f'Navigation ended with status {result.status}')
+            self._publish_nav_status(f'failed:status={result.status}')
+
+    def _cancel_navigation(self, reason: str) -> None:
+        if self._nav_goal_handle is not None and self._nav_active:
+            self.get_logger().info(f'Cancelling navigation: {reason}')
+            self._nav_goal_handle.cancel_goal_async()
+        self._nav_active = False
+        self._publish_nav_status(f'cancelled:{reason}')
+
+    # ── Helpers ───────────────────────────────────────────────────────────────
+
+    def _filter_waypoints(self, poses: list) -> list:
+        """Remove waypoints closer than waypoint_spacing_m to previous."""
+        spacing = self.get_parameter('waypoint_spacing_m').value
+        out = [poses[0]]
+        for p in poses[1:]:
+            prev = out[-1]
+            d = math.hypot(
+                p.position.x - prev.position.x,
+                p.position.y - prev.position.y,
+            )
+            if d >= spacing:
+                out.append(p)
+        return out
+
+    def _publish_gps_status(self) -> None:
+        if self._fix is None:
+            status = 'no_fix'
+        elif self._fix.status.status < 0:
+            status = 'no_fix'
+        elif self._fix.status.status >= _RTK_FIX_STATUS:
+            status = f'rtk_fixed lat={self._fix.latitude:.6f} lon={self._fix.longitude:.6f}'
+        elif self._fix.status.status >= NavSatStatus.STATUS_FIX:
+            cov = self._fix.position_covariance[0] ** 0.5 if self._fix.position_covariance[0] > 0 else 2.5
+            status = f'fix_ok cep~{cov:.1f}m lat={self._fix.latitude:.6f} lon={self._fix.longitude:.6f}'
+        else:
+            status = f'poor_fix status={self._fix.status.status}'
+        msg = String()
+        msg.data = status
+        self._gps_status_pub.publish(msg)
+
+    def _publish_nav_status(self, s: str) -> None:
+        msg = String()
+        msg.data = s
+        self._nav_status_pub.publish(msg)
+
+
+def main(args=None):
+    rclpy.init(args=args)
+    node = GpsWaypointFollowerNode()
+    executor = MultiThreadedExecutor()
+    executor.add_node(node)
+    try:
+        executor.spin()
+    except KeyboardInterrupt:
+        pass
+    finally:
+        node.destroy_node()
+        rclpy.try_shutdown()
+
+
+if __name__ == '__main__':
+    main()

jetson/ros2_ws/src/saltybot_outdoor/saltybot_outdoor/osm_router_node.py

@@ -0,0 +1,371 @@
+"""
+osm_router_node — OpenStreetMap sidewalk/bike-lane route planner
+
+Given a start and goal GPS coordinate, this node:
+  1. Queries the Overpass API for pedestrian/cycleway ways within a
+     configurable radius around the midpoint
+  2. Builds a weighted graph (edge weight = haversine distance)
+  3. Runs A* (Dijkstra fallback) to find the shortest walkable path
+  4. Simplifies the waypoint list (Douglas–Peucker, ~5m spacing)
+  5. Converts lat/lon waypoints to map-frame PoseStamped via
+     robot_localization's /fromLL service
+  6. Publishes the route as nav_msgs/Path for RViz visualisation
+  7. Returns the PoseArray to the GPS waypoint follower
+
+ROS services:
+  /outdoor/plan_route  (saltybot_outdoor_msgs or std_srvs — see PlanRoute below)
+
+Topics published:
+  /outdoor/route   nav_msgs/Path    — map-frame path for RViz
+  /outdoor/status  std_msgs/String  — 'idle' | 'planning' | 'ready' | 'error:<msg>'
+
+Topics subscribed:
+  /gps/fix   sensor_msgs/NavSatFix  — current robot position
+
+Hardware:
+  SIM7600X cellular module publishes /gps/fix at ~1 Hz (±2.5 m CEP)
+  RTK upgrade path: swap to ZED-F9P for ±2 cm (see config/outdoor_nav_params.yaml)
+
+Overpass query: fetches highway=footway|cycleway|path|pedestrian|living_street
+within a bounding box, then prunes to walking-accessible ways only.
+
+Dependencies:
+  pip3 install requests   (Overpass HTTP)
+  No osmnx required — native JSON parsing keeps Docker image lean.
+"""
+
+import json
+import math
+import heapq
+import time
+from typing import Optional
+
+import rclpy
+from rclpy.node import Node
+from rclpy.callback_groups import ReentrantCallbackGroup
+
+from sensor_msgs.msg import NavSatFix
+from nav_msgs.msg import Path
+from geometry_msgs.msg import PoseStamped, PoseArray, Pose, Point
+from std_msgs.msg import String
+from std_srvs.srv import Trigger
+
+try:
+    import requests
+    _REQUESTS_OK = True
+except ImportError:
+    _REQUESTS_OK = False
+
+
+# OSM highway types considered walkable
+_WALKABLE = frozenset([
+    'footway', 'cycleway', 'path', 'pedestrian',
+    'living_street', 'residential', 'service',
+    'track', 'steps',
+])
+
+_OVERPASS_URL = 'https://overpass-api.de/api/interpreter'
+_OVERPASS_TIMEOUT = 20   # seconds
+
+
+# ── Haversine distance ────────────────────────────────────────────────────────
+
+def _haversine(lat1: float, lon1: float, lat2: float, lon2: float) -> float:
+    """Great-circle distance in metres."""
+    R = 6_371_000.0
+    phi1, phi2 = math.radians(lat1), math.radians(lat2)
+    dphi = math.radians(lat2 - lat1)
+    dlam = math.radians(lon2 - lon1)
+    a = math.sin(dphi / 2) ** 2 + math.cos(phi1) * math.cos(phi2) * math.sin(dlam / 2) ** 2
+    return R * 2 * math.atan2(math.sqrt(a), math.sqrt(1 - a))
+
+
+# ── Douglas–Peucker polyline simplification ───────────────────────────────────
+
+def _perp_dist(pt, line_a, line_b):
+    """Cross-track distance from pt to segment a–b (all in lat/lon)."""
+    lat, lon = pt
+    la, lo_a = line_a
+    lb, lo_b = line_b
+    dx, dy = lb - la, lo_b - lo_a
+    if dx == 0 and dy == 0:
+        return _haversine(lat, lon, la, lo_a)
+    t = ((lat - la) * dx + (lon - lo_a) * dy) / (dx * dx + dy * dy)
+    t = max(0.0, min(1.0, t))
+    return _haversine(lat, lon, la + t * dx, lo_a + t * dy)
+
+
+def _douglas_peucker(points: list, epsilon_m: float) -> list:
+    """Reduce waypoints, keeping points > epsilon_m from simplified line."""
+    if len(points) <= 2:
+        return points
+    dmax, idx = 0.0, 0
+    end = points[-1]
+    for i in range(1, len(points) - 1):
+        d = _perp_dist(points[i], points[0], end)
+        if d > dmax:
+            dmax, idx = d, i
+    if dmax > epsilon_m:
+        left  = _douglas_peucker(points[:idx + 1], epsilon_m)
+        right = _douglas_peucker(points[idx:],     epsilon_m)
+        return left[:-1] + right
+    return [points[0], points[-1]]
+
+
+# ── A* on OSM graph ───────────────────────────────────────────────────────────
+
+def _astar(graph: dict, start: int, goal: int, coords: dict) -> Optional[list]:
+    """A* over OSM node graph. Returns list of node IDs or None."""
+    if start not in graph or goal not in graph:
+        return None
+    glat, glon = coords[goal]
+
+    def h(n):
+        return _haversine(coords[n][0], coords[n][1], glat, glon)
+
+    open_heap = [(h(start), 0.0, start, [start])]
+    visited = set()
+    while open_heap:
+        f, g, node, path = heapq.heappop(open_heap)
+        if node in visited:
+            continue
+        visited.add(node)
+        if node == goal:
+            return path
+        for nb, w in graph[node]:
+            if nb not in visited:
+                ng = g + w
+                heapq.heappush(open_heap, (ng + h(nb), ng, nb, path + [nb]))
+    return None
+
+
+# ── OSM graph builder ─────────────────────────────────────────────────────────
+
+def _build_graph(elements: list) -> tuple[dict, dict]:
+    """Parse Overpass JSON elements into adjacency list + coordinate dict."""
+    node_coords: dict[int, tuple[float, float]] = {}
+    graph: dict[int, list] = {}
+
+    for el in elements:
+        if el['type'] == 'node':
+            node_coords[el['id']] = (el['lat'], el['lon'])
+
+    for el in elements:
+        if el['type'] != 'way':
+            continue
+        highway = el.get('tags', {}).get('highway', '')
+        if highway not in _WALKABLE:
+            continue
+        nodes = el['nodes']
+        for i in range(len(nodes) - 1):
+            a, b = nodes[i], nodes[i + 1]
+            if a not in node_coords or b not in node_coords:
+                continue
+            w = _haversine(*node_coords[a], *node_coords[b])
+            graph.setdefault(a, []).append((b, w))
+            graph.setdefault(b, []).append((a, w))   # bidirectional
+
+    return graph, node_coords
+
+
+def _nearest_node(lat: float, lon: float, coords: dict) -> int:
+    """Return ID of OSM node nearest to (lat, lon)."""
+    return min(coords, key=lambda n: _haversine(lat, lon, *coords[n]))
+
+
+# ── ROS node ──────────────────────────────────────────────────────────────────
+
+class OsmRouterNode(Node):
+
+    def __init__(self):
+        super().__init__('osm_router')
+
+        self.declare_parameter('overpass_url',      _OVERPASS_URL)
+        self.declare_parameter('query_radius_m',    1500.0)   # area to fetch
+        self.declare_parameter('simplify_eps_m',    5.0)      # waypoint spacing
+        self.declare_parameter('cache_dir',         '/data/osm_cache')
+        self.declare_parameter('use_cache',         True)
+        self.declare_parameter('map_frame',         'map')
+
+        self._fix: Optional[NavSatFix] = None
+        self._cb_group = ReentrantCallbackGroup()
+
+        # ── Subscriptions ────────────────────────────────────────────────────
+        self.create_subscription(NavSatFix, '/gps/fix', self._fix_cb, 10)
+
+        # ── Publishers ───────────────────────────────────────────────────────
+        self._path_pub   = self.create_publisher(Path,        '/outdoor/route',  10)
+        self._status_pub = self.create_publisher(String,      '/outdoor/status', 10)
+        self._poses_pub  = self.create_publisher(PoseArray,   '/outdoor/waypoints', 10)
+
+        # ── Services ─────────────────────────────────────────────────────────
+        # /outdoor/plan_route — not yet triggered, called externally with goal.
+        # Goal lat/lon passed as parameter overrides for simplicity in V1.
+        self.declare_parameter('goal_lat', 0.0)
+        self.declare_parameter('goal_lon', 0.0)
+        self.create_service(
+            Trigger, '/outdoor/plan_route',
+            self._plan_route_cb,
+            callback_group=self._cb_group,
+        )
+
+        self._publish_status('idle')
+        self.get_logger().info('osm_router: ready. Call /outdoor/plan_route to start.')
+
+    # ── Callbacks ─────────────────────────────────────────────────────────────
+
+    def _fix_cb(self, msg: NavSatFix) -> None:
+        self._fix = msg
+
+    def _plan_route_cb(self, _req, response):
+        if self._fix is None:
+            response.success = False
+            response.message = 'No GPS fix yet'
+            return response
+
+        goal_lat = self.get_parameter('goal_lat').value
+        goal_lon = self.get_parameter('goal_lon').value
+        if goal_lat == 0.0 and goal_lon == 0.0:
+            response.success = False
+            response.message = 'goal_lat/goal_lon not set'
+            return response
+
+        self._publish_status('planning')
+        try:
+            path_msg, pose_array = self._plan(
+                self._fix.latitude, self._fix.longitude,
+                goal_lat, goal_lon,
+            )
+            self._path_pub.publish(path_msg)
+            self._poses_pub.publish(pose_array)
+            self._publish_status('ready')
+            response.success = True
+            response.message = f'{len(pose_array.poses)} waypoints planned'
+        except Exception as exc:
+            self.get_logger().error(f'Route planning failed: {exc}')
+            self._publish_status(f'error:{exc}')
+            response.success = False
+            response.message = str(exc)
+        return response
+
+    # ── Planning ──────────────────────────────────────────────────────────────
+
+    def _plan(self, slat, slon, glat, glon) -> tuple[Path, PoseArray]:
+        radius = self.get_parameter('query_radius_m').value
+        eps    = self.get_parameter('simplify_eps_m').value
+        frame  = self.get_parameter('map_frame').value
+
+        # Bounding box centred on midpoint
+        mlat = (slat + glat) / 2
+        mlon = (slon + glon) / 2
+        d_deg = (radius / 111_320.0) * 1.5   # pad
+        bbox = (mlat - d_deg, mlon - d_deg, mlat + d_deg, mlon + d_deg)
+
+        elements = self._fetch_osm(bbox)
+        graph, coords = _build_graph(elements)
+
+        if not coords:
+            raise RuntimeError('No walkable OSM nodes in query area')
+
+        start_node = _nearest_node(slat, slon, coords)
+        goal_node  = _nearest_node(glat, glon, coords)
+
+        node_path = _astar(graph, start_node, goal_node, coords)
+        if node_path is None:
+            raise RuntimeError('No walkable path found between start and goal')
+
+        raw_pts = [coords[n] for n in node_path]
+        simplified = _douglas_peucker(raw_pts, eps)
+
+        self.get_logger().info(
+            f'Route: {len(raw_pts)} → {len(simplified)} waypoints after simplification'
+        )
+
+        # Build nav_msgs/Path in map frame using ENU approximation.
+        # navsat_transform_node provides the GPS→map projection; here we use
+        # a local flat-earth approximation centred on the start position.
+        # Replace with /fromLL service call when robot_localization is running.
+        path_msg  = Path()
+        pose_arr  = PoseArray()
+        now = self.get_clock().now().to_msg()
+        path_msg.header.stamp = now
+        path_msg.header.frame_id = frame
+        pose_arr.header = path_msg.header
+
+        lat0, lon0 = slat, slon
+        for lat, lon in simplified:
+            x, y = _latlon_to_enu(lat, lon, lat0, lon0)
+            ps = PoseStamped()
+            ps.header = path_msg.header
+            ps.pose.position.x = x
+            ps.pose.position.y = y
+            ps.pose.orientation.w = 1.0
+            path_msg.poses.append(ps)
+
+            p = Pose()
+            p.position.x = x
+            p.position.y = y
+            p.orientation.w = 1.0
+            pose_arr.poses.append(p)
+
+        return path_msg, pose_arr
+
+    # ── Overpass fetch ────────────────────────────────────────────────────────
+
+    def _fetch_osm(self, bbox: tuple) -> list:
+        """Query Overpass for walkable ways in bbox. Returns element list."""
+        if not _REQUESTS_OK:
+            raise RuntimeError('requests library not installed (pip3 install requests)')
+
+        s, w, n, e = bbox
+        query = f"""
+[out:json][timeout:{_OVERPASS_TIMEOUT}];
+(
+  way["highway"~"^(footway|cycleway|path|pedestrian|living_street|residential|service|track|steps)$"]
+     ({s:.6f},{w:.6f},{n:.6f},{e:.6f});
+);
+out body;
+>;
+out skel qt;
+"""
+        url = self.get_parameter('overpass_url').value
+        self.get_logger().info(f'Querying Overpass: bbox={s:.4f},{w:.4f},{n:.4f},{e:.4f}')
+        resp = requests.post(url, data={'data': query}, timeout=_OVERPASS_TIMEOUT + 5)
+        resp.raise_for_status()
+        data = resp.json()
+        elements = data.get('elements', [])
+        self.get_logger().info(f'Overpass returned {len(elements)} elements')
+        return elements
+
+    # ── Helpers ───────────────────────────────────────────────────────────────
+
+    def _publish_status(self, msg: str) -> None:
+        s = String()
+        s.data = msg
+        self._status_pub.publish(s)
+
+
+def _latlon_to_enu(lat: float, lon: float, lat0: float, lon0: float) -> tuple[float, float]:
+    """Flat-earth ENU approximation (valid within ~10 km)."""
+    dlat = math.radians(lat - lat0)
+    dlon = math.radians(lon - lon0)
+    cos0 = math.cos(math.radians(lat0))
+    x = dlon * cos0 * 6_371_000.0   # East
+    y = dlat * 6_371_000.0           # North
+    return x, y
+
+
+def main(args=None):
+    rclpy.init(args=args)
+    node = OsmRouterNode()
+    try:
+        rclpy.spin(node)
+    except KeyboardInterrupt:
+        pass
+    finally:
+        node.destroy_node()
+        rclpy.try_shutdown()
+
+
+if __name__ == '__main__':
+    main()

jetson/ros2_ws/src/saltybot_outdoor/setup.cfg

@@ -0,0 +1,4 @@
+[develop]
+script_dir=$base/lib/saltybot_outdoor
+[install]
+install_scripts=$base/lib/saltybot_outdoor

jetson/ros2_ws/src/saltybot_outdoor/setup.py

@@ -0,0 +1,34 @@
+import os
+from glob import glob
+from setuptools import find_packages, setup
+
+package_name = 'saltybot_outdoor'
+
+setup(
+    name=package_name,
+    version='0.1.0',
+    packages=find_packages(exclude=['test']),
+    data_files=[
+        ('share/ament_index/resource_index/packages',
+         ['resource/' + package_name]),
+        ('share/' + package_name, ['package.xml']),
+        (os.path.join('share', package_name, 'launch'),
+         glob('launch/*.py')),
+        (os.path.join('share', package_name, 'config'),
+         glob('config/*.yaml')),
+    ],
+    install_requires=['setuptools'],
+    zip_safe=True,
+    maintainer='seb',
+    maintainer_email='seb@saltylab.io',
+    description='Outdoor navigation: OSM routing, GPS waypoint following, geofence',
+    license='MIT',
+    tests_require=['pytest'],
+    entry_points={
+        'console_scripts': [
+            'osm_router_node       = saltybot_outdoor.osm_router_node:main',
+            'gps_waypoint_follower = saltybot_outdoor.gps_waypoint_follower_node:main',
+            'geofence_node         = saltybot_outdoor.geofence_node:main',
+        ],
+    },
+)

jetson/ros2_ws/src/saltybot_routes/config/route_params.yaml

@@ -0,0 +1,83 @@
+# route_params.yaml — Route recording and replay configuration for SaltyBot
+#
+# "Ride once, replay forever."
+#
+# Flow:
+#   1. Tee rides EUC, SaltyBot follows via UWB follow-me (PR #66)
+#   2. route_recorder_node samples GPS + odom → /data/routes/<name>.jsonl
+#   3. Next ride: route_replayer_node loads file → Nav2 navigate_through_poses
+#
+# GPS source: SIM7600X → /gps/fix (NavSatFix, ±2.5m CEP) — PR #65
+# Heading:    D435i IMU → /imu/data, converted yaw → route waypoint heading_deg
+# Odometry:   STM32 wheel encoders → /odom
+# UWB:        /uwb/target (follow-me reference, logged for context)
+
+route_recorder:
+  ros__parameters:
+    save_dir:           "/data/routes"
+    route_name:         "route"            # override via param or launch arg
+    waypoint_spacing_m: 2.0               # skip GPS samples closer than this
+    sample_rate_hz:     1.0               # max recording frequency (GPS ~1Hz)
+    min_fix_status:     0                 # 0=STATUS_FIX; reject STATUS_NO_FIX (-1)
+
+route_replayer:
+  ros__parameters:
+    save_dir:             "/data/routes"
+    route_name:           "route"
+    replay_spacing_m:     3.0             # subsample waypoints for Nav2 (3m spacing)
+    goal_tolerance_xy:    2.0             # metres — matches SIM7600X ±2.5m CEP
+    replay_speed_factor:  1.0             # 1.0 = same speed as recorded
+    map_frame:            "map"
+    nav_timeout_s:        600.0           # 10 min max per nav batch
+
+route_manager:
+  ros__parameters:
+    save_dir:    "/data/routes"
+    route_name:  "route"
+
+# ── Operational notes ─────────────────────────────────────────────────────────
+#
+# Recording a route (EUC follow-me session):
+#   ros2 param set /route_recorder route_name "friday_loop"
+#   ros2 service call /route/start_recording std_srvs/srv/Trigger '{}'
+#   # ... follow Tee for the full route ...
+#   ros2 service call /route/stop_recording std_srvs/srv/Trigger '{}'
+#   ros2 service call /route/save std_srvs/srv/Trigger '{}'
+#
+# Replaying a route (autonomous):
+#   ros2 param set /route_replayer route_name "friday_loop"
+#   ros2 service call /route/load std_srvs/srv/Trigger '{}'
+#   ros2 service call /route/start_replay std_srvs/srv/Trigger '{}'
+#   ros2 topic echo /route/replay_status
+#
+# Listing routes:
+#   ros2 service call /route/list std_srvs/srv/Trigger '{}'
+#
+# Route info:
+#   ros2 param set /route_manager route_name "friday_loop"
+#   ros2 service call /route/info std_srvs/srv/Trigger '{}'
+#
+# Delete route:
+#   ros2 param set /route_manager route_name "friday_loop"
+#   ros2 service call /route/delete std_srvs/srv/Trigger '{}'
+#
+# Emergency stop during replay:
+#   ros2 service call /route/stop std_srvs/srv/Trigger '{}'
+#   # or: ros2 topic pub /route/pause_cmd std_msgs/msg/Bool '{data: true}'
+#
+# ── File format (JSON Lines, .jsonl) ─────────────────────────────────────────
+#
+# {
+#   "version": 1,
+#   "name": "friday_loop",
+#   "recorded_at": "2026-03-01T14:22:00+00:00",
+#   "waypoint_count": 142,
+#   "total_distance_m": 1240.5,
+#   "duration_s": 820.3,
+#   "waypoints": [
+#     {"t": 1740839000.1, "lat": 37.7749, "lon": -122.4194,
+#      "heading_deg": 45.0, "speed_mps": 1.2, "odom_x": 0.0, "odom_y": 0.0,
+#      "gps_status": 0},
+#     ...
+#   ]
+# }

jetson/ros2_ws/src/saltybot_routes/launch/route_system.launch.py

@@ -0,0 +1,99 @@
+"""
+route_system.launch.py — Route recording and replay system for SaltyBot
+
+Starts:
+  route_recorder_node  — records GPS + odom path during follow-me rides
+  route_replayer_node  — replays recorded routes autonomously via Nav2
+  route_manager_node   — list/delete/info for saved routes
+
+Depends on:
+  saltybot-nav2 container (Nav2 action server /navigate_through_poses)
+  saltybot_cellular (/gps/fix from SIM7600X GPS — PR #65)
+  saltybot_uwb (/uwb/target — PR #66, used for context during recording)
+  STM32 bridge (/odom from wheel encoders)
+  D435i (/imu/data for heading)
+
+Usage — record a route:
+  # Set name, start recording, ride with Tee, stop and save:
+  ros2 param set /route_recorder route_name "friday_loop"
+  ros2 service call /route/start_recording std_srvs/srv/Trigger '{}'
+  # ... ride the route ...
+  ros2 service call /route/stop_recording std_srvs/srv/Trigger '{}'
+  ros2 service call /route/save std_srvs/srv/Trigger '{}'
+
+Usage — replay a route:
+  ros2 param set /route_replayer route_name "friday_loop"
+  ros2 service call /route/load std_srvs/srv/Trigger '{}'
+  ros2 service call /route/start_replay std_srvs/srv/Trigger '{}'
+
+Arguments:
+  save_dir      (default /data/routes) — NVMe route storage
+  route_name    (default route)        — name for record/replay
+"""
+
+import os
+from ament_index_python.packages import get_package_share_directory
+
+from launch import LaunchDescription
+from launch.actions import DeclareLaunchArgument
+from launch.substitutions import LaunchConfiguration
+from launch_ros.actions import Node
+
+
+def generate_launch_description():
+    pkg_dir    = get_package_share_directory('saltybot_routes')
+    params_file = os.path.join(pkg_dir, 'config', 'route_params.yaml')
+
+    args = [
+        DeclareLaunchArgument('save_dir',   default_value='/data/routes'),
+        DeclareLaunchArgument('route_name', default_value='route'),
+    ]
+
+    recorder = Node(
+        package='saltybot_routes',
+        executable='route_recorder_node',
+        name='route_recorder',
+        output='screen',
+        parameters=[
+            params_file,
+            {
+                'save_dir':   LaunchConfiguration('save_dir'),
+                'route_name': LaunchConfiguration('route_name'),
+            },
+        ],
+    )
+
+    replayer = Node(
+        package='saltybot_routes',
+        executable='route_replayer_node',
+        name='route_replayer',
+        output='screen',
+        parameters=[
+            params_file,
+            {
+                'save_dir':   LaunchConfiguration('save_dir'),
+                'route_name': LaunchConfiguration('route_name'),
+            },
+        ],
+    )
+
+    manager = Node(
+        package='saltybot_routes',
+        executable='route_manager_node',
+        name='route_manager',
+        output='screen',
+        parameters=[
+            params_file,
+            {
+                'save_dir':   LaunchConfiguration('save_dir'),
+                'route_name': LaunchConfiguration('route_name'),
+            },
+        ],
+    )
+
+    return LaunchDescription([
+        *args,
+        recorder,
+        replayer,
+        manager,
+    ])

jetson/ros2_ws/src/saltybot_routes/package.xml

@@ -0,0 +1,31 @@
+<?xml version="1.0"?>
+<?xml-model href="http://download.ros.org/schema/package_format3.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?>
+<package format="3">
+  <name>saltybot_routes</name>
+  <version>0.1.0</version>
+  <description>Route recording and autonomous replay for SaltyBot — "Ride once, replay forever."</description>
+  <maintainer email="seb@saltylab.io">seb</maintainer>
+  <license>MIT</license>
+
+  <buildtool_depend>ament_python</buildtool_depend>
+
+  <depend>rclpy</depend>
+  <depend>sensor_msgs</depend>
+  <depend>geometry_msgs</depend>
+  <depend>nav_msgs</depend>
+  <depend>std_msgs</depend>
+  <depend>std_srvs</depend>
+  <depend>nav2_msgs</depend>
+
+  <exec_depend>robot_localization</exec_depend>
+  <exec_depend>nav2_bringup</exec_depend>
+
+  <test_depend>ament_copyright</test_depend>
+  <test_depend>ament_flake8</test_depend>
+  <test_depend>ament_pep257</test_depend>
+  <test_depend>pytest</test_depend>
+
+  <export>
+    <build_type>ament_python</build_type>
+  </export>
+</package>

jetson/ros2_ws/src/saltybot_routes/saltybot_routes/route_manager_node.py

@@ -0,0 +1,149 @@
+"""
+route_manager_node — List, inspect, and delete saved route files.
+
+Provides a management interface for the /data/routes/ directory.
+All routes are .jsonl files written by route_recorder_node.
+
+Services:
+  /route/list    std_srvs/Trigger  — returns JSON list of all routes in status message
+  /route/delete  std_srvs/Trigger  — delete route named by route_name param
+  /route/info    std_srvs/Trigger  — return metadata for route named by route_name param
+
+Parameters:
+  save_dir     (default /data/routes)
+  route_name   (default 'route')   — used by /route/delete and /route/info
+
+Topics published:
+  /route/manager_status  std_msgs/String  — last operation result
+
+Response format (in message field):
+  /route/list → JSON string: [{"name":..., "distance_m":..., "recorded_at":..., "waypoint_count":...}, ...]
+  /route/info → JSON string: {full metadata dict}
+  /route/delete → "Deleted: <name>"
+"""
+
+import json
+import os
+from datetime import datetime, timezone
+
+import rclpy
+from rclpy.node import Node
+
+from std_msgs.msg import String
+from std_srvs.srv import Trigger
+
+
+class RouteManagerNode(Node):
+
+    def __init__(self):
+        super().__init__('route_manager')
+
+        self.declare_parameter('save_dir',    '/data/routes')
+        self.declare_parameter('route_name',  'route')
+
+        self._status_pub = self.create_publisher(String, '/route/manager_status', 10)
+
+        self.create_service(Trigger, '/route/list',   self._list_cb)
+        self.create_service(Trigger, '/route/delete', self._delete_cb)
+        self.create_service(Trigger, '/route/info',   self._info_cb)
+
+        self.get_logger().info('route_manager: ready.')
+
+    # ── Service handlers ──────────────────────────────────────────────────────
+
+    def _list_cb(self, _req, response):
+        save_dir = self.get_parameter('save_dir').value
+        if not os.path.isdir(save_dir):
+            response.success = True
+            response.message = '[]'
+            return response
+
+        routes = []
+        for fname in sorted(os.listdir(save_dir)):
+            if not fname.endswith('.jsonl'):
+                continue
+            path = os.path.join(save_dir, fname)
+            try:
+                with open(path) as f:
+                    meta = json.load(f)
+                routes.append({
+                    'name':          meta.get('name', fname[:-6]),
+                    'distance_m':    meta.get('total_distance_m', 0.0),
+                    'duration_s':    meta.get('duration_s', 0.0),
+                    'recorded_at':   meta.get('recorded_at', ''),
+                    'waypoint_count': meta.get('waypoint_count', 0),
+                    'file':          fname,
+                })
+            except Exception as e:
+                self.get_logger().warn(f'route_manager: could not read {fname}: {e}')
+
+        result = json.dumps(routes)
+        self._pub_status(f'list:{len(routes)}_routes')
+        response.success = True
+        response.message = result
+        self.get_logger().info(f'route_manager: listed {len(routes)} routes')
+        return response
+
+    def _delete_cb(self, _req, response):
+        name     = self.get_parameter('route_name').value
+        save_dir = self.get_parameter('save_dir').value
+        path     = os.path.join(save_dir, f'{name}.jsonl')
+
+        if not os.path.exists(path):
+            response.success = False
+            response.message = f'Route not found: {name}'
+            return response
+
+        os.remove(path)
+        self._pub_status(f'deleted:{name}')
+        self.get_logger().info(f'route_manager: deleted "{name}"')
+        response.success = True
+        response.message = f'Deleted: {name}'
+        return response
+
+    def _info_cb(self, _req, response):
+        name     = self.get_parameter('route_name').value
+        save_dir = self.get_parameter('save_dir').value
+        path     = os.path.join(save_dir, f'{name}.jsonl')
+
+        if not os.path.exists(path):
+            response.success = False
+            response.message = f'Route not found: {name}'
+            return response
+
+        try:
+            with open(path) as f:
+                meta = json.load(f)
+            # Return metadata without the full waypoints array (can be large)
+            info = {k: v for k, v in meta.items() if k != 'waypoints'}
+            result = json.dumps(info, indent=2)
+            self._pub_status(f'info:{name}')
+            response.success = True
+            response.message = result
+        except Exception as e:
+            response.success = False
+            response.message = f'Error reading route: {e}'
+        return response
+
+    # ── Helpers ───────────────────────────────────────────────────────────────
+
+    def _pub_status(self, s: str) -> None:
+        msg = String()
+        msg.data = s
+        self._status_pub.publish(msg)
+
+
+def main(args=None):
+    rclpy.init(args=args)
+    node = RouteManagerNode()
+    try:
+        rclpy.spin(node)
+    except KeyboardInterrupt:
+        pass
+    finally:
+        node.destroy_node()
+        rclpy.try_shutdown()
+
+
+if __name__ == '__main__':
+    main()

jetson/ros2_ws/src/saltybot_routes/saltybot_routes/route_recorder_node.py

@@ -0,0 +1,317 @@
+"""
+route_recorder_node — Records GPS + odometry path during follow-me rides.
+
+"Ride once, replay forever." — During a UWB follow-me session, this node
+samples the robot's GPS position, heading, and speed into a timestamped
+JSON-Lines file. The result is a portable route file that route_replayer_node
+can load to autonomously repeat the ride.
+
+Recording strategy:
+  - Samples at up to 1 Hz (configurable)
+  - Skips waypoints within waypoint_spacing_m of the previous one
+  - Each waypoint: {t, lat, lon, heading_deg, speed_mps, x, y, source}
+  - source: 'gps' | 'odom' (used when GPS quality drops)
+
+JSON-Lines format (one JSON object per line, .jsonl):
+  {"version": 1, "name": "...", "recorded_at": "...", "waypoints": [...]}
+  Written as a single-line header on line 1 (metadata), then appended to.
+
+File location: /data/routes/<name>.jsonl
+
+Topics subscribed:
+  /gps/fix          sensor_msgs/NavSatFix   — GPS position (SIM7600X)
+  /odom             nav_msgs/Odometry       — wheel encoder odometry
+  /uwb/target       geometry_msgs/PoseStamped — UWB target position (for context)
+  /imu/data         sensor_msgs/Imu         — heading from IMU
+
+Topics published:
+  /route/status     std_msgs/String  — 'idle'|'recording:<name>'|'saved:<name>'
+
+Services:
+  /route/start_recording  std_srvs/Trigger  — begin recording (name via param)
+  /route/stop_recording   std_srvs/Trigger  — stop and buffer (don't save yet)
+  /route/save             std_srvs/Trigger  — flush buffer to disk
+  /route/discard          std_srvs/Trigger  — discard unsaved recording
+
+Parameters:
+  save_dir            (default /data/routes)
+  waypoint_spacing_m  (default 2.0) — skip closer waypoints
+  sample_rate_hz      (default 1.0) — max recording rate
+  route_name          (default 'route') — set before start_recording
+  min_fix_status      (default 0)  — reject STATUS_NO_FIX
+"""
+
+import json
+import math
+import os
+import time
+from datetime import datetime, timezone
+from typing import Optional
+
+import rclpy
+from rclpy.node import Node
+from rclpy.callback_groups import ReentrantCallbackGroup
+
+from sensor_msgs.msg import NavSatFix, NavSatStatus, Imu
+from nav_msgs.msg import Odometry
+from geometry_msgs.msg import PoseStamped
+from std_msgs.msg import String
+from std_srvs.srv import Trigger
+
+
+def _haversine(lat1: float, lon1: float, lat2: float, lon2: float) -> float:
+    """Great-circle distance in metres."""
+    R = 6_371_000.0
+    phi1, phi2 = math.radians(lat1), math.radians(lat2)
+    dphi = math.radians(lat2 - lat1)
+    dlam = math.radians(lon2 - lon1)
+    a = math.sin(dphi / 2) ** 2 + math.cos(phi1) * math.cos(phi2) * math.sin(dlam / 2) ** 2
+    return R * 2 * math.atan2(math.sqrt(a), math.sqrt(1 - a))
+
+
+def _quat_to_yaw_deg(q) -> float:
+    """Convert quaternion to yaw in degrees (-180..180)."""
+    siny = 2.0 * (q.w * q.z + q.x * q.y)
+    cosy = 1.0 - 2.0 * (q.y * q.y + q.z * q.z)
+    return math.degrees(math.atan2(siny, cosy))
+
+
+class RouteRecorderNode(Node):
+
+    def __init__(self):
+        super().__init__('route_recorder')
+
+        self.declare_parameter('save_dir',           '/data/routes')
+        self.declare_parameter('waypoint_spacing_m', 2.0)
+        self.declare_parameter('sample_rate_hz',     1.0)
+        self.declare_parameter('route_name',         'route')
+        self.declare_parameter('min_fix_status',     NavSatStatus.STATUS_FIX)
+
+        self._recording = False
+        self._waypoints: list[dict] = []
+        self._last_wp:   Optional[dict] = None
+        self._last_sample_t = 0.0
+
+        # Latest sensor state
+        self._fix:    Optional[NavSatFix]     = None
+        self._odom:   Optional[Odometry]      = None
+        self._imu:    Optional[Imu]           = None
+        self._uwb:    Optional[PoseStamped]   = None
+
+        self._cb_group = ReentrantCallbackGroup()
+
+        # ── Subscriptions ────────────────────────────────────────────────────
+        self.create_subscription(NavSatFix,    '/gps/fix',     self._fix_cb,  10)
+        self.create_subscription(Odometry,     '/odom',        self._odom_cb, 10)
+        self.create_subscription(Imu,          '/imu/data',    self._imu_cb,  10)
+        self.create_subscription(PoseStamped,  '/uwb/target',  self._uwb_cb,  10)
+
+        # ── Publishers ───────────────────────────────────────────────────────
+        self._status_pub = self.create_publisher(String, '/route/status', 10)
+
+        # ── Services ─────────────────────────────────────────────────────────
+        self.create_service(Trigger, '/route/start_recording', self._start_cb,
+                            callback_group=self._cb_group)
+        self.create_service(Trigger, '/route/stop_recording',  self._stop_cb,
+                            callback_group=self._cb_group)
+        self.create_service(Trigger, '/route/save',            self._save_cb,
+                            callback_group=self._cb_group)
+        self.create_service(Trigger, '/route/discard',         self._discard_cb,
+                            callback_group=self._cb_group)
+
+        # ── Sample timer ─────────────────────────────────────────────────────
+        rate = self.get_parameter('sample_rate_hz').value
+        self.create_timer(1.0 / rate, self._sample)
+
+        self._pub_status('idle')
+        self.get_logger().info('route_recorder: ready. Call /route/start_recording.')
+
+    # ── Sensor callbacks ──────────────────────────────────────────────────────
+
+    def _fix_cb(self, msg: NavSatFix) -> None:
+        self._fix = msg
+
+    def _odom_cb(self, msg: Odometry) -> None:
+        self._odom = msg
+
+    def _imu_cb(self, msg: Imu) -> None:
+        self._imu = msg
+
+    def _uwb_cb(self, msg: PoseStamped) -> None:
+        self._uwb = msg
+
+    # ── Service handlers ──────────────────────────────────────────────────────
+
+    def _start_cb(self, _req, response):
+        if self._recording:
+            response.success = False
+            response.message = 'Already recording'
+            return response
+
+        name = self.get_parameter('route_name').value
+        self._waypoints = []
+        self._last_wp = None
+        self._recording = True
+        self.get_logger().info(f'route_recorder: started recording "{name}"')
+        self._pub_status(f'recording:{name}')
+        response.success = True
+        response.message = f'Recording started: {name}'
+        return response
+
+    def _stop_cb(self, _req, response):
+        if not self._recording:
+            response.success = False
+            response.message = 'Not recording'
+            return response
+        self._recording = False
+        n = len(self._waypoints)
+        self.get_logger().info(f'route_recorder: stopped. {n} waypoints buffered.')
+        self._pub_status(f'stopped:{n}_waypoints')
+        response.success = True
+        response.message = f'Recording stopped. {n} waypoints buffered. Call /route/save.'
+        return response
+
+    def _save_cb(self, _req, response):
+        if not self._waypoints:
+            response.success = False
+            response.message = 'No waypoints to save'
+            return response
+
+        name = self.get_parameter('route_name').value
+        save_dir = self.get_parameter('save_dir').value
+        os.makedirs(save_dir, exist_ok=True)
+        path = os.path.join(save_dir, f'{name}.jsonl')
+
+        total_dist = self._total_distance_m()
+        meta = {
+            'version':      1,
+            'name':         name,
+            'recorded_at':  datetime.now(timezone.utc).isoformat(),
+            'waypoint_count': len(self._waypoints),
+            'total_distance_m': round(total_dist, 1),
+            'duration_s':   self._duration_s(),
+            'waypoints':    self._waypoints,
+        }
+        with open(path, 'w') as f:
+            json.dump(meta, f)
+            f.write('\n')
+
+        self.get_logger().info(
+            f'route_recorder: saved {len(self._waypoints)} waypoints → {path} '
+            f'({total_dist:.0f} m)'
+        )
+        self._pub_status(f'saved:{name}')
+        self._waypoints = []
+        response.success = True
+        response.message = f'Saved: {path} ({len(meta["waypoints"])} waypoints, {total_dist:.0f} m)'
+        return response
+
+    def _discard_cb(self, _req, response):
+        n = len(self._waypoints)
+        self._waypoints = []
+        self._recording = False
+        self._last_wp = None
+        self._pub_status('idle')
+        response.success = True
+        response.message = f'Discarded {n} waypoints'
+        return response
+
+    # ── Sample timer ──────────────────────────────────────────────────────────
+
+    def _sample(self) -> None:
+        if not self._recording:
+            return
+        if self._fix is None:
+            return
+
+        # GPS quality check
+        min_status = self.get_parameter('min_fix_status').value
+        if self._fix.status.status < min_status:
+            return
+
+        lat = self._fix.latitude
+        lon = self._fix.longitude
+
+        # Skip if too close to last waypoint
+        spacing = self.get_parameter('waypoint_spacing_m').value
+        if self._last_wp is not None:
+            d = _haversine(lat, lon, self._last_wp['lat'], self._last_wp['lon'])
+            if d < spacing:
+                return
+
+        # Heading: prefer IMU yaw, fall back to GPS bearing
+        heading_deg = 0.0
+        if self._imu is not None:
+            heading_deg = _quat_to_yaw_deg(self._imu.orientation)
+        elif self._last_wp is not None:
+            dlat = lat - self._last_wp['lat']
+            dlon = lon - self._last_wp['lon']
+            heading_deg = math.degrees(math.atan2(dlon, dlat))
+
+        # Speed from odometry
+        speed_mps = 0.0
+        odom_x, odom_y = 0.0, 0.0
+        if self._odom is not None:
+            vx = self._odom.twist.twist.linear.x
+            vy = self._odom.twist.twist.linear.y
+            speed_mps = math.hypot(vx, vy)
+            odom_x = self._odom.pose.pose.position.x
+            odom_y = self._odom.pose.pose.position.y
+
+        wp = {
+            't':           self.get_clock().now().nanoseconds / 1e9,
+            'lat':         lat,
+            'lon':         lon,
+            'heading_deg': round(heading_deg, 1),
+            'speed_mps':   round(speed_mps, 2),
+            'odom_x':      round(odom_x, 3),
+            'odom_y':      round(odom_y, 3),
+            'gps_status':  self._fix.status.status,
+        }
+
+        self._waypoints.append(wp)
+        self._last_wp = wp
+
+        name = self.get_parameter('route_name').value
+        self.get_logger().debug(
+            f'route_recorder: wp #{len(self._waypoints)} '
+            f'lat={lat:.6f} lon={lon:.6f} hdg={heading_deg:.0f}° spd={speed_mps:.1f}m/s'
+        )
+        self._pub_status(f'recording:{name}:{len(self._waypoints)}_wps')
+
+    # ── Helpers ───────────────────────────────────────────────────────────────
+
+    def _total_distance_m(self) -> float:
+        if len(self._waypoints) < 2:
+            return 0.0
+        total = 0.0
+        for i in range(1, len(self._waypoints)):
+            a, b = self._waypoints[i - 1], self._waypoints[i]
+            total += _haversine(a['lat'], a['lon'], b['lat'], b['lon'])
+        return total
+
+    def _duration_s(self) -> float:
+        if len(self._waypoints) < 2:
+            return 0.0
+        return self._waypoints[-1]['t'] - self._waypoints[0]['t']
+
+    def _pub_status(self, s: str) -> None:
+        msg = String()
+        msg.data = s
+        self._status_pub.publish(msg)
+
+
+def main(args=None):
+    rclpy.init(args=args)
+    node = RouteRecorderNode()
+    try:
+        rclpy.spin(node)
+    except KeyboardInterrupt:
+        pass
+    finally:
+        node.destroy_node()
+        rclpy.try_shutdown()
+
+
+if __name__ == '__main__':
+    main()

jetson/ros2_ws/src/saltybot_routes/saltybot_routes/route_replayer_node.py

@@ -0,0 +1,389 @@
+"""
+route_replayer_node — Loads and autonomously replays a recorded route.
+
+"Ride once, replay forever." — Loads a .jsonl route file, converts GPS
+waypoints to map-frame PoseStamped via robot_localization's flat-earth
+ENU projection, then sends batches to Nav2's navigate_through_poses action.
+
+Replay strategy:
+  1. Load route file → list of {lat, lon, heading_deg, ...}
+  2. Convert GPS → map-frame ENU (relative to first fix / datum)
+  3. Subsample waypoints by replay_spacing_m (default 3m)
+  4. Inject heading from recorded data (preserved via quaternion)
+  5. Send full waypoint list to Nav2 navigate_through_poses
+  6. Monitor feedback; pause/resume on demand
+  7. Odometry correction: compare current odom position to expected odom
+     position and log drift for future closed-loop correction (V1: log only)
+
+GPS drift handling:
+  - Use wider goal tolerance (2m default — matches SIM7600X CEP)
+  - Slow down near waypoints (Nav2 DWB sim_time reduces automatically)
+  - Report GPS covariance in status so operator can monitor quality
+
+Topics subscribed:
+  /gps/fix          sensor_msgs/NavSatFix
+  /odom             nav_msgs/Odometry
+  /route/pause_cmd  std_msgs/Bool  — True=pause, False=resume
+
+Topics published:
+  /route/replay_status  std_msgs/String  — state machine status
+  /route/progress       std_msgs/String  — 'N/M waypoints, D m remaining'
+
+Actions called:
+  /navigate_through_poses  nav2_msgs/action/NavigateThroughPoses
+
+Services:
+  /route/load          std_srvs/Trigger  — load route named by route_name param
+  /route/start_replay  std_srvs/Trigger  — begin replay
+  /route/pause         std_srvs/Trigger  — pause (cancel Nav2 goal, hold position)
+  /route/stop          std_srvs/Trigger  — abort replay
+"""
+
+import json
+import math
+import os
+from typing import Optional
+
+import rclpy
+from rclpy.node import Node
+from rclpy.action import ActionClient
+from rclpy.callback_groups import ReentrantCallbackGroup
+from rclpy.executors import MultiThreadedExecutor
+
+from sensor_msgs.msg import NavSatFix, NavSatStatus
+from nav_msgs.msg import Odometry
+from geometry_msgs.msg import PoseStamped, PoseArray, Pose
+from std_msgs.msg import String, Bool
+from std_srvs.srv import Trigger
+
+from nav2_msgs.action import NavigateThroughPoses
+
+
+def _haversine(lat1, lon1, lat2, lon2) -> float:
+    R = 6_371_000.0
+    phi1, phi2 = math.radians(lat1), math.radians(lat2)
+    dphi = math.radians(lat2 - lat1)
+    dlam = math.radians(lon2 - lon1)
+    a = math.sin(dphi / 2) ** 2 + math.cos(phi1) * math.cos(phi2) * math.sin(dlam / 2) ** 2
+    return R * 2 * math.atan2(math.sqrt(a), math.sqrt(1 - a))
+
+
+def _latlon_to_enu(lat: float, lon: float, lat0: float, lon0: float):
+    """Flat-earth ENU approximation (valid ~10 km)."""
+    dlat = math.radians(lat - lat0)
+    dlon = math.radians(lon - lon0)
+    cos0 = math.cos(math.radians(lat0))
+    x = dlon * cos0 * 6_371_000.0
+    y = dlat * 6_371_000.0
+    return x, y
+
+
+def _heading_to_quat(heading_deg: float) -> tuple:
+    """Convert heading (degrees, 0=North, CW) to ENU quaternion (0=East, CCW)."""
+    # In ENU: x=East, y=North. yaw=0 → facing East.
+    # Heading: 0=North, 90=East. Convert: yaw_enu = 90 - heading_deg
+    yaw = math.radians(90.0 - heading_deg)
+    return (0.0, 0.0, math.sin(yaw / 2), math.cos(yaw / 2))   # x, y, z, w
+
+
+class RouteReplayerNode(Node):
+
+    def __init__(self):
+        super().__init__('route_replayer')
+
+        self.declare_parameter('save_dir',          '/data/routes')
+        self.declare_parameter('route_name',        'route')
+        self.declare_parameter('replay_spacing_m',  3.0)   # subsample spacing
+        self.declare_parameter('goal_tolerance_xy', 2.0)   # GPS ±2.5m CEP
+        self.declare_parameter('replay_speed_factor', 1.0) # 1.0 = same speed as recorded
+        self.declare_parameter('map_frame',         'map')
+        self.declare_parameter('nav_timeout_s',     600.0) # 10 min
+
+        self._route:    Optional[dict]         = None   # loaded route metadata
+        self._fix:      Optional[NavSatFix]    = None
+        self._odom:     Optional[Odometry]     = None
+        self._paused    = False
+        self._active    = False
+        self._nav_goal_handle = None
+
+        self._cb_group = ReentrantCallbackGroup()
+
+        # ── Subscriptions ────────────────────────────────────────────────────
+        self.create_subscription(NavSatFix, '/gps/fix',         self._fix_cb,   10)
+        self.create_subscription(Odometry,  '/odom',            self._odom_cb,  10)
+        self.create_subscription(Bool,      '/route/pause_cmd', self._pause_cb, 10)
+
+        # ── Publishers ───────────────────────────────────────────────────────
+        self._status_pub   = self.create_publisher(String, '/route/replay_status', 10)
+        self._progress_pub = self.create_publisher(String, '/route/progress',      10)
+
+        # ── Services ─────────────────────────────────────────────────────────
+        self.create_service(Trigger, '/route/load',          self._load_cb,
+                            callback_group=self._cb_group)
+        self.create_service(Trigger, '/route/start_replay',  self._start_cb,
+                            callback_group=self._cb_group)
+        self.create_service(Trigger, '/route/pause',         self._pause_svc_cb,
+                            callback_group=self._cb_group)
+        self.create_service(Trigger, '/route/stop',          self._stop_cb,
+                            callback_group=self._cb_group)
+
+        # ── Nav2 action client ───────────────────────────────────────────────
+        self._nav_client = ActionClient(
+            self, NavigateThroughPoses, '/navigate_through_poses',
+            callback_group=self._cb_group,
+        )
+
+        # ── Progress timer ────────────────────────────────────────────────────
+        self.create_timer(2.0, self._publish_progress)
+
+        self._pub_status('idle')
+        self.get_logger().info('route_replayer: ready. Call /route/load then /route/start_replay.')
+
+    # ── Sensor callbacks ──────────────────────────────────────────────────────
+
+    def _fix_cb(self, msg: NavSatFix) -> None:
+        self._fix = msg
+
+    def _odom_cb(self, msg: Odometry) -> None:
+        self._odom = msg
+
+    def _pause_cb(self, msg: Bool) -> None:
+        if msg.data and not self._paused:
+            self._pause_replay()
+        elif not msg.data and self._paused:
+            self._resume_replay()
+
+    # ── Service handlers ──────────────────────────────────────────────────────
+
+    def _load_cb(self, _req, response):
+        name    = self.get_parameter('route_name').value
+        dir_    = self.get_parameter('save_dir').value
+        path    = os.path.join(dir_, f'{name}.jsonl')
+
+        if not os.path.exists(path):
+            response.success = False
+            response.message = f'Route file not found: {path}'
+            return response
+
+        with open(path) as f:
+            self._route = json.load(f)
+
+        n    = self._route.get('waypoint_count', len(self._route.get('waypoints', [])))
+        dist = self._route.get('total_distance_m', 0.0)
+        dur  = self._route.get('duration_s', 0.0)
+
+        self.get_logger().info(
+            f'route_replayer: loaded "{name}" — {n} waypoints, '
+            f'{dist:.0f} m, {dur:.0f} s'
+        )
+        self._pub_status(f'loaded:{name}:{n}_waypoints:{dist:.0f}m')
+        response.success = True
+        response.message = f'Loaded: {name} ({n} waypoints, {dist:.0f} m, {dur:.0f} s)'
+        return response
+
+    def _start_cb(self, _req, response):
+        if self._route is None:
+            response.success = False
+            response.message = 'No route loaded — call /route/load first'
+            return response
+
+        if self._active:
+            response.success = False
+            response.message = 'Replay already active'
+            return response
+
+        if self._fix is None:
+            response.success = False
+            response.message = 'No GPS fix'
+            return response
+
+        if self._fix.status.status < NavSatStatus.STATUS_FIX:
+            response.success = False
+            response.message = f'GPS quality too low: status={self._fix.status.status}'
+            return response
+
+        # Kick off async nav
+        self.create_timer(0.1, self._send_nav_goal, callback_group=self._cb_group)
+        response.success = True
+        name = self._route.get('name', '?')
+        response.message = f'Starting replay of "{name}"'
+        return response
+
+    def _pause_svc_cb(self, _req, response):
+        if self._paused:
+            self._resume_replay()
+            response.message = 'Replay resumed'
+        else:
+            self._pause_replay()
+            response.message = 'Replay paused'
+        response.success = True
+        return response
+
+    def _stop_cb(self, _req, response):
+        self._cancel_nav('stop requested')
+        response.success = True
+        response.message = 'Replay stopped'
+        return response
+
+    # ── Navigation ────────────────────────────────────────────────────────────
+
+    def _send_nav_goal(self) -> None:
+        """One-shot timer: convert route waypoints → Nav2 goal."""
+        self.destroy_timer(list(self.timers)[-1])
+
+        if not self._nav_client.wait_for_server(timeout_sec=5.0):
+            self.get_logger().error('Nav2 not available')
+            self._pub_status('error:nav2_unavailable')
+            return
+
+        waypoints = self._route.get('waypoints', [])
+        if not waypoints:
+            self.get_logger().error('Route has no waypoints')
+            self._pub_status('error:empty_route')
+            return
+
+        # Use current GPS fix as datum for ENU origin
+        lat0 = self._fix.latitude
+        lon0 = self._fix.longitude
+
+        # Subsample by spacing
+        spacing = self.get_parameter('replay_spacing_m').value
+        sampled = self._subsample_waypoints(waypoints, spacing)
+
+        frame = self.get_parameter('map_frame').value
+        now   = self.get_clock().now().to_msg()
+        goal  = NavigateThroughPoses.Goal()
+
+        for wp in sampled:
+            x, y = _latlon_to_enu(wp['lat'], wp['lon'], lat0, lon0)
+            qx, qy, qz, qw = _heading_to_quat(wp.get('heading_deg', 0.0))
+
+            ps = PoseStamped()
+            ps.header.stamp    = now
+            ps.header.frame_id = frame
+            ps.pose.position.x = x
+            ps.pose.position.y = y
+            ps.pose.orientation.x = qx
+            ps.pose.orientation.y = qy
+            ps.pose.orientation.z = qz
+            ps.pose.orientation.w = qw
+            goal.poses.append(ps)
+
+        name = self._route.get('name', '?')
+        self.get_logger().info(
+            f'route_replayer: sending {len(goal.poses)} waypoints to Nav2 '
+            f'(from {len(waypoints)} recorded, datum={lat0:.6f},{lon0:.6f})'
+        )
+        self._pub_status(f'replaying:{name}:{len(goal.poses)}_waypoints')
+        self._active = True
+        self._paused = False
+
+        future = self._nav_client.send_goal_async(
+            goal,
+            feedback_callback=self._nav_feedback_cb,
+        )
+        future.add_done_callback(self._nav_goal_response_cb)
+
+    def _nav_goal_response_cb(self, future) -> None:
+        self._nav_goal_handle = future.result()
+        if not self._nav_goal_handle.accepted:
+            self.get_logger().error('Nav2 rejected replay goal')
+            self._active = False
+            self._pub_status('error:goal_rejected')
+            return
+        result_future = self._nav_goal_handle.get_result_async()
+        result_future.add_done_callback(self._nav_result_cb)
+
+    def _nav_feedback_cb(self, feedback) -> None:
+        fb = feedback.feedback
+        remaining = getattr(fb, 'number_of_poses_remaining', '?')
+        dist = getattr(fb, 'distance_remaining', None)
+        if dist is not None:
+            self.get_logger().info(
+                f'replay: {remaining} waypoints remaining, {dist:.1f} m to go',
+                throttle_duration_sec=10.0,
+            )
+
+    def _nav_result_cb(self, future) -> None:
+        self._active = False
+        result = future.result()
+        name   = self._route.get('name', '?') if self._route else '?'
+        if result.status == 4:
+            self.get_logger().info(f'Replay of "{name}" completed successfully')
+            self._pub_status(f'completed:{name}')
+        else:
+            self.get_logger().warn(f'Replay ended with status {result.status}')
+            self._pub_status(f'failed:{name}:status={result.status}')
+
+    def _pause_replay(self) -> None:
+        if self._nav_goal_handle and self._active:
+            self._nav_goal_handle.cancel_goal_async()
+        self._paused = True
+        self._active = False
+        self._pub_status('paused')
+        self.get_logger().info('route_replayer: paused')
+
+    def _resume_replay(self) -> None:
+        """Re-issue the nav goal from current position (simple re-start)."""
+        self._paused = False
+        if self._route:
+            self.create_timer(0.1, self._send_nav_goal, callback_group=self._cb_group)
+            self._pub_status('resuming')
+            self.get_logger().info('route_replayer: resuming')
+
+    def _cancel_nav(self, reason: str) -> None:
+        if self._nav_goal_handle and self._active:
+            self._nav_goal_handle.cancel_goal_async()
+        self._active = False
+        self._paused = False
+        self._pub_status(f'stopped:{reason}')
+        self.get_logger().info(f'route_replayer: stopped — {reason}')
+
+    # ── Helpers ───────────────────────────────────────────────────────────────
+
+    def _subsample_waypoints(self, waypoints: list, spacing_m: float) -> list:
+        """Keep waypoints at least spacing_m apart. Always keep first + last."""
+        if not waypoints:
+            return []
+        out = [waypoints[0]]
+        for wp in waypoints[1:-1]:
+            prev = out[-1]
+            d = _haversine(wp['lat'], wp['lon'], prev['lat'], prev['lon'])
+            if d >= spacing_m:
+                out.append(wp)
+        if len(waypoints) > 1:
+            out.append(waypoints[-1])
+        return out
+
+    def _publish_progress(self) -> None:
+        if not self._active or self._route is None:
+            return
+        name = self._route.get('name', '?')
+        n    = self._route.get('waypoint_count', '?')
+        dist = self._route.get('total_distance_m', 0.0)
+        msg = String()
+        msg.data = f'replaying:{name} total={n}wps dist={dist:.0f}m'
+        self._progress_pub.publish(msg)
+
+    def _pub_status(self, s: str) -> None:
+        msg = String()
+        msg.data = s
+        self._status_pub.publish(msg)
+
+
+def main(args=None):
+    rclpy.init(args=args)
+    node = RouteReplayerNode()
+    executor = MultiThreadedExecutor()
+    executor.add_node(node)
+    try:
+        executor.spin()
+    except KeyboardInterrupt:
+        pass
+    finally:
+        node.destroy_node()
+        rclpy.try_shutdown()
+
+
+if __name__ == '__main__':
+    main()

jetson/ros2_ws/src/saltybot_routes/setup.cfg

@@ -0,0 +1,4 @@
+[develop]
+script_dir=$base/lib/saltybot_routes
+[install]
+install_scripts=$base/lib/saltybot_routes

jetson/ros2_ws/src/saltybot_routes/setup.py

@@ -0,0 +1,34 @@
+import os
+from glob import glob
+from setuptools import find_packages, setup
+
+package_name = 'saltybot_routes'
+
+setup(
+    name=package_name,
+    version='0.1.0',
+    packages=find_packages(exclude=['test']),
+    data_files=[
+        ('share/ament_index/resource_index/packages',
+         ['resource/' + package_name]),
+        ('share/' + package_name, ['package.xml']),
+        (os.path.join('share', package_name, 'launch'),
+         glob('launch/*.py')),
+        (os.path.join('share', package_name, 'config'),
+         glob('config/*.yaml')),
+    ],
+    install_requires=['setuptools'],
+    zip_safe=True,
+    maintainer='seb',
+    maintainer_email='seb@saltylab.io',
+    description='Route recording and autonomous replay — ride once, replay forever.',
+    license='MIT',
+    tests_require=['pytest'],
+    entry_points={
+        'console_scripts': [
+            'route_recorder_node  = saltybot_routes.route_recorder_node:main',
+            'route_replayer_node  = saltybot_routes.route_replayer_node:main',
+            'route_manager_node   = saltybot_routes.route_manager_node:main',
+        ],
+    },
+)

jetson/ros2_ws/src/saltybot_segmentation/config/segmentation_params.yaml

@@ -0,0 +1,64 @@
+# segmentation_params.yaml — SaltyBot sidewalk semantic segmentation
+#
+# Run with:
+#   ros2 launch saltybot_segmentation sidewalk_segmentation.launch.py
+#
+# Build TRT engine first (run ONCE on the Jetson):
+#   python3 /opt/ros/humble/share/saltybot_segmentation/scripts/build_engine.py
+
+# ── Model paths ───────────────────────────────────────────────────────────────
+# Priority: TRT engine > ONNX > error (no inference)
+#
+# Build engine:
+#   python3 build_engine.py --model bisenetv2
+#   → /mnt/nvme/saltybot/models/bisenetv2_cityscapes_512x256.engine
+engine_path: /mnt/nvme/saltybot/models/bisenetv2_cityscapes_512x256.engine
+onnx_path:   /mnt/nvme/saltybot/models/bisenetv2_cityscapes_512x256.onnx
+
+# ── Model input size ──────────────────────────────────────────────────────────
+# Must match the engine. 512×256 maintains Cityscapes 2:1 aspect ratio.
+# RealSense 640×480 is letterboxed to 512×256 (pillarboxed, 32px each side).
+input_width:  512
+input_height: 256
+
+# ── Processing rate ───────────────────────────────────────────────────────────
+# process_every_n: run inference on 1 in N frames.
+#   1 = every frame  (~15fps if latency budget allows)
+#   2 = every 2nd frame (recommended — RealSense @ 30fps → ~15fps effective)
+#   3 = every 3rd frame (9fps — use if GPU is constrained by other tasks)
+#
+# RealSense color at 15fps → process_every_n:=1 gives ~15fps seg output.
+process_every_n: 1
+
+# ── Debug image ───────────────────────────────────────────────────────────────
+# Set true to publish /segmentation/debug_image (BGR colour overlay).
+# Adds ~1ms/frame overhead. Disable in production.
+publish_debug_image: false
+
+# ── Traversability overrides ──────────────────────────────────────────────────
+# unknown_as_obstacle: true → sky / unlabelled pixels → lethal (100).
+#   Use in dense urban environments where unknowns are likely vertical surfaces.
+#   Use false (default) in open spaces to allow exploration.
+unknown_as_obstacle: false
+
+# ── Costmap projection ────────────────────────────────────────────────────────
+# costmap_resolution: metres per cell in the output OccupancyGrid.
+#   Match or exceed Nav2 local_costmap resolution (default 0.05m).
+costmap_resolution: 0.05     # metres/cell
+
+# costmap_range_m: forward look-ahead distance for ground projection.
+#   5.0m covers 100 cells at 0.05m resolution.
+#   Increase for faster outdoor navigation; decrease for tight indoor spaces.
+costmap_range_m: 5.0         # metres
+
+# ── Camera geometry ───────────────────────────────────────────────────────────
+# These must match the RealSense mount position on the robot.
+# Used for inverse-perspective ground projection.
+#
+# camera_height_m: height of RealSense optical centre above ground (metres).
+#   saltybot: D435i mounted at ~0.15m above base_link origin.
+camera_height_m: 0.15        # metres
+
+# camera_pitch_deg: downward tilt of the camera (degrees, positive = tilted down).
+#   0 = horizontal. Typical outdoor deployment: 5–10° downward.
+camera_pitch_deg: 5.0        # degrees

jetson/ros2_ws/src/saltybot_segmentation/docs/training_guide.md

@@ -0,0 +1,268 @@
+# Sidewalk Segmentation — Training & Deployment Guide
+
+## Overview
+
+SaltyBot uses **BiSeNetV2** (default) or **DDRNet-23-slim** for real-time semantic
+segmentation, pre-trained on Cityscapes and optionally fine-tuned on site-specific data.
+
+The model runs at **>15fps on Orin Nano Super** via TensorRT FP16 at 512×256 input,
+publishing per-pixel traversability costs to Nav2.
+
+---
+
+## Traversability Classes
+
+| Class | ID | OccupancyGrid | Description |
+|-------|----|---------------|-------------|
+| Sidewalk | 0 | 0 (free) | Preferred navigation surface |
+| Grass/vegetation | 1 | 50 (medium) | Traversable but non-preferred |
+| Road | 2 | 90 (high cost) | Avoid but can cross |
+| Obstacle | 3 | 100 (lethal) | Person, car, building, fence |
+| Unknown | 4 | -1 (unknown) | Sky, unlabelled |
+
+---
+
+## Quick Start — Pretrained Cityscapes Model
+
+No training required for standard sidewalks in Western cities.
+
+```bash
+# 1. Build the TRT engine (once, on Orin):
+python3 /opt/ros/humble/share/saltybot_segmentation/scripts/build_engine.py
+
+# 2. Launch:
+ros2 launch saltybot_segmentation sidewalk_segmentation.launch.py
+
+# 3. Verify:
+ros2 topic hz /segmentation/mask        # expect ~15Hz
+ros2 topic hz /segmentation/costmap     # expect ~15Hz
+ros2 run rviz2 rviz2                    # add OccupancyGrid, topic=/segmentation/costmap
+```
+
+---
+
+## Model Benchmarks — Cityscapes Validation Set
+
+| Model | mIoU | Sidewalk IoU | Road IoU | FPS (Orin FP16) | Engine size |
+|-------|------|--------------|----------|-----------------|-------------|
+| BiSeNetV2 | 72.6% | 82.1% | 97.8% | ~50 fps | ~11 MB |
+| DDRNet-23-slim | 79.5% | 84.3% | 98.1% | ~40 fps | ~18 MB |
+
+Both exceed the **>15fps target** with headroom for additional ROS2 overhead.
+
+BiSeNetV2 is the default — faster, smaller, sufficient for traversability.
+Use DDRNet if mIoU matters more than latency (e.g., complex European city centres).
+
+---
+
+## Fine-Tuning on Custom Site Data
+
+### When is fine-tuning needed?
+
+The Cityscapes-trained model works well for:
+- European-style city sidewalks, curbs, roads
+- Standard pedestrian infrastructure
+
+Fine-tuning improves performance for:
+- Gravel/dirt paths (not in Cityscapes)
+- Unusual kerb styles or non-standard pavement markings
+- Indoor+outdoor transitions (garage exits, building entrances)
+- Non-Western road infrastructure
+
+### Step 1 — Collect data (walk the route)
+
+Record a ROS2 bag while walking the intended robot route:
+
+```bash
+# On Orin, record the front camera for 5–10 minutes of the target environment:
+ros2 bag record /camera/color/image_raw -o sidewalk_route_2024-01
+
+# Transfer to workstation for labelling:
+scp -r jetson:/home/ubuntu/sidewalk_route_2024-01 ~/datasets/
+```
+
+### Step 2 — Extract frames
+
+```bash
+python3 fine_tune.py \
+    --extract-frames ~/datasets/sidewalk_route_2024-01/ \
+    --output-dir ~/datasets/sidewalk_raw/ \
+    --every-n 5       # 1 frame per 5 = ~6fps from 30fps bag
+```
+
+This extracts ~200–400 frames from a 5-minute bag. You need to label **50–100 frames** minimum.
+
+### Step 3 — Label with LabelMe
+
+```bash
+pip install labelme
+labelme ~/datasets/sidewalk_raw/
+```
+
+**Class names to use** (must be exact):
+
+| What you see | LabelMe label |
+|--------------|---------------|
+| Footpath/pavement | `sidewalk` |
+| Road/tarmac | `road` |
+| Grass/lawn/verge | `vegetation` |
+| Gravel path | `terrain` |
+| Person | `person` |
+| Car/vehicle | `car` |
+| Building/wall | `building` |
+| Fence/gate | `fence` |
+
+**Labelling tips:**
+- Use **polygon** tool for precise boundaries
+- Focus on the ground plane (lower 60% of image) — that's what the costmap uses
+- 50 well-labelled frames beats 200 rushed ones
+- Vary conditions: sunny, overcast, morning, evening
+
+### Step 4 — Convert labels to masks
+
+```bash
+python3 fine_tune.py \
+    --convert-labels ~/datasets/sidewalk_raw/ \
+    --output-dir ~/datasets/sidewalk_masks/
+```
+
+Output: `<frame>_mask.png` per frame — 8-bit PNG with Cityscapes class IDs.
+Unlabelled pixels are set to 255 (ignored during training).
+
+### Step 5 — Fine-tune
+
+```bash
+# On Orin (or workstation with CUDA):
+python3 fine_tune.py --train \
+    --images  ~/datasets/sidewalk_raw/ \
+    --labels  ~/datasets/sidewalk_masks/ \
+    --weights /mnt/nvme/saltybot/models/bisenetv2_cityscapes.pth \
+    --output  /mnt/nvme/saltybot/models/bisenetv2_custom.pth \
+    --epochs  20 \
+    --lr      1e-4
+```
+
+Expected training time:
+- 50 images, 20 epochs, Orin: ~15 minutes
+- 100 images, 20 epochs, Orin: ~25 minutes
+
+### Step 6 — Evaluate mIoU
+
+```bash
+python3 fine_tune.py --eval \
+    --images ~/datasets/sidewalk_raw/ \
+    --labels ~/datasets/sidewalk_masks/ \
+    --weights /mnt/nvme/saltybot/models/bisenetv2_custom.pth
+```
+
+Target mIoU on custom classes: >70% on sidewalk/road/obstacle.
+
+### Step 7 — Build new TRT engine
+
+```bash
+python3 build_engine.py \
+    --weights /mnt/nvme/saltybot/models/bisenetv2_custom.pth \
+    --engine  /mnt/nvme/saltybot/models/bisenetv2_custom_512x256.engine
+```
+
+Update `segmentation_params.yaml`:
+```yaml
+engine_path: /mnt/nvme/saltybot/models/bisenetv2_custom_512x256.engine
+```
+
+---
+
+## Nav2 Integration — SegmentationCostmapLayer
+
+Add to `nav2_params.yaml`:
+
+```yaml
+local_costmap:
+  local_costmap:
+    ros__parameters:
+      plugins:
+        - "voxel_layer"
+        - "inflation_layer"
+        - "segmentation_layer"   # ← add this
+
+      segmentation_layer:
+        plugin: "saltybot_segmentation_costmap::SegmentationCostmapLayer"
+        enabled: true
+        topic: /segmentation/costmap
+        combination_method: max     # max | override | min
+```
+
+**combination_method:**
+- `max` (default) — keeps the worst-case cost between existing costmap and segmentation.
+  Most conservative; prevents Nav2 from overriding obstacle detections.
+- `override` — segmentation completely replaces existing cell costs.
+  Use when you trust the camera more than other sensors.
+- `min` — keeps the most permissive cost.
+  Use for exploratory navigation in open environments.
+
+---
+
+## Performance Tuning
+
+### Too slow (<15fps)
+
+1. **Reduce process_every_n** (e.g., `process_every_n: 2` → effective 15fps from 30fps camera)
+2. **Reduce input resolution** — edit `build_engine.py` to use 384×192 (2.2× faster)
+3. **Ensure nvpmodel is in MAXN mode**: `sudo nvpmodel -m 0 && sudo jetson_clocks`
+4. Check GPU is not throttled: `jtop` → GPU frequency should be 1024MHz
+
+### False road detections (sidewalk near road)
+
+- Lower `camera_pitch_deg` to look further ahead
+- Enable `unknown_as_obstacle: true` to be more cautious
+- Fine-tune with site-specific data (Step 5)
+
+### Costmap looks noisy
+
+- Increase `costmap_resolution` (0.1m cells reduce noise)
+- Reduce `costmap_range_m` to 3.0m (projection less accurate at far range)
+- Apply temporal smoothing in Nav2 inflation layer
+
+---
+
+## Datasets
+
+### Cityscapes (primary pre-training)
+- **2975 training / 500 validation** finely annotated images
+- 19 semantic classes (roads, sidewalks, people, vehicles, etc.)
+- License: Cityscapes Terms of Use (non-commercial research)
+- Download: https://www.cityscapes-dataset.com/
+- Required for training from scratch; BiSeNetV2 pretrained checkpoint (~25MB) available at:
+  https://github.com/CoinCheung/BiSeNet/releases
+
+### Mapillary Vistas (supplementary)
+- **18,000 training images** from diverse global street scenes
+- 124 semantic classes (broader coverage than Cityscapes)
+- Includes dirt paths, gravel, unusual sidewalk types
+- License: CC BY-SA 4.0
+- Download: https://www.mapillary.com/dataset/vistas
+- Useful for mapping to our traversability classes in non-European environments
+
+### Custom saltybot data
+- Collected per-deployment via `fine_tune.py --extract-frames`
+- 50–100 labelled frames typical for 80%+ mIoU on specific routes
+- Store in `/mnt/nvme/saltybot/training_data/`
+
+---
+
+## File Locations on Orin
+
+```
+/mnt/nvme/saltybot/
+├── models/
+│   ├── bisenetv2_cityscapes.pth              ← downloaded pretrained weights
+│   ├── bisenetv2_cityscapes_512x256.onnx     ← exported ONNX (FP32)
+│   ├── bisenetv2_cityscapes_512x256.engine   ← TRT FP16 engine (built on Orin)
+│   ├── bisenetv2_custom.pth                  ← fine-tuned weights (after step 5)
+│   └── bisenetv2_custom_512x256.engine       ← TRT FP16 engine (after step 7)
+├── training_data/
+│   ├── raw/                                  ← extracted JPEG frames
+│   └── labels/                              ← LabelMe JSON + converted PNG masks
+└── rosbags/
+    └── sidewalk_route_*/                     ← recorded ROS2 bags for labelling
+```

jetson/ros2_ws/src/saltybot_segmentation/launch/sidewalk_segmentation.launch.py

@@ -0,0 +1,58 @@
+"""
+sidewalk_segmentation.launch.py — Launch semantic sidewalk segmentation node.
+
+Usage:
+  ros2 launch saltybot_segmentation sidewalk_segmentation.launch.py
+  ros2 launch saltybot_segmentation sidewalk_segmentation.launch.py publish_debug_image:=true
+  ros2 launch saltybot_segmentation sidewalk_segmentation.launch.py engine_path:=/custom/model.engine
+"""
+
+import os
+from ament_index_python.packages import get_package_share_directory
+from launch import LaunchDescription
+from launch.actions import DeclareLaunchArgument
+from launch.substitutions import LaunchConfiguration
+from launch_ros.actions import Node
+
+
+def generate_launch_description():
+    pkg = get_package_share_directory("saltybot_segmentation")
+    cfg = os.path.join(pkg, "config", "segmentation_params.yaml")
+
+    return LaunchDescription([
+        DeclareLaunchArgument("engine_path",
+            default_value="/mnt/nvme/saltybot/models/bisenetv2_cityscapes_512x256.engine",
+            description="Path to TensorRT .engine file"),
+        DeclareLaunchArgument("onnx_path",
+            default_value="/mnt/nvme/saltybot/models/bisenetv2_cityscapes_512x256.onnx",
+            description="Path to ONNX fallback model"),
+        DeclareLaunchArgument("process_every_n", default_value="1",
+            description="Run inference every N frames (1=every frame)"),
+        DeclareLaunchArgument("publish_debug_image", default_value="false",
+            description="Publish colour-coded debug image on /segmentation/debug_image"),
+        DeclareLaunchArgument("unknown_as_obstacle", default_value="false",
+            description="Treat unknown pixels as lethal obstacles"),
+        DeclareLaunchArgument("costmap_range_m", default_value="5.0",
+            description="Forward look-ahead range for costmap projection (m)"),
+        DeclareLaunchArgument("camera_pitch_deg", default_value="5.0",
+            description="Camera downward pitch angle (degrees)"),
+
+        Node(
+            package="saltybot_segmentation",
+            executable="sidewalk_seg",
+            name="sidewalk_seg",
+            output="screen",
+            parameters=[
+                cfg,
+                {
+                    "engine_path":          LaunchConfiguration("engine_path"),
+                    "onnx_path":            LaunchConfiguration("onnx_path"),
+                    "process_every_n":      LaunchConfiguration("process_every_n"),
+                    "publish_debug_image":  LaunchConfiguration("publish_debug_image"),
+                    "unknown_as_obstacle":  LaunchConfiguration("unknown_as_obstacle"),
+                    "costmap_range_m":      LaunchConfiguration("costmap_range_m"),
+                    "camera_pitch_deg":     LaunchConfiguration("camera_pitch_deg"),
+                },
+            ],
+        ),
+    ])

jetson/ros2_ws/src/saltybot_segmentation/package.xml

@@ -0,0 +1,32 @@
+<?xml version="1.0"?>
+<?xml-model href="http://download.ros.org/schema/package_format3.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?>
+<package format="3">
+  <name>saltybot_segmentation</name>
+  <version>0.1.0</version>
+  <description>
+    Semantic sidewalk segmentation for SaltyBot outdoor autonomous navigation.
+    BiSeNetV2 / DDRNet-23-slim with TensorRT FP16 on Orin Nano Super.
+    Publishes traversability mask + Nav2 OccupancyGrid costmap.
+  </description>
+  <maintainer email="seb@vayrette.com">seb</maintainer>
+  <license>MIT</license>
+
+  <buildtool_depend>ament_python</buildtool_depend>
+
+  <depend>rclpy</depend>
+  <depend>sensor_msgs</depend>
+  <depend>nav_msgs</depend>
+  <depend>std_msgs</depend>
+  <depend>cv_bridge</depend>
+  <depend>python3-numpy</depend>
+  <depend>python3-opencv</depend>
+
+  <test_depend>ament_copyright</test_depend>
+  <test_depend>ament_flake8</test_depend>
+  <test_depend>ament_pep257</test_depend>
+  <test_depend>pytest</test_depend>
+
+  <export>
+    <build_type>ament_python</build_type>
+  </export>
+</package>

jetson/ros2_ws/src/saltybot_segmentation/saltybot_segmentation/seg_utils.py

@@ -0,0 +1,273 @@
+"""
+seg_utils.py — Pure helpers for semantic segmentation and traversability mapping.
+
+No ROS2, TensorRT, or PyTorch imports — fully testable without GPU or ROS2 install.
+
+Cityscapes 19-class → 5-class traversability mapping
+──────────────────────────────────────────────────────
+  Cityscapes ID → Traversability class → OccupancyGrid value
+
+  0  road         → ROAD      → 90   (high cost — don't drive on road)
+  1  sidewalk     → SIDEWALK  → 0    (free — preferred surface)
+  2  building     → OBSTACLE  → 100  (lethal)
+  3  wall         → OBSTACLE  → 100
+  4  fence        → OBSTACLE  → 100
+  5  pole         → OBSTACLE  → 100
+  6  traffic light→ OBSTACLE  → 100
+  7  traffic sign → OBSTACLE  → 100
+  8  vegetation   → GRASS     → 50   (medium — can traverse slowly)
+  9  terrain      → GRASS     → 50
+  10 sky          → UNKNOWN   → -1   (unknown)
+  11 person       → OBSTACLE  → 100  (lethal — safety critical)
+  12 rider        → OBSTACLE  → 100
+  13 car          → OBSTACLE  → 100
+  14 truck        → OBSTACLE  → 100
+  15 bus          → OBSTACLE  → 100
+  16 train        → OBSTACLE  → 100
+  17 motorcycle   → OBSTACLE  → 100
+  18 bicycle      → OBSTACLE  → 100
+
+Segmentation mask class IDs (published on /segmentation/mask)
+─────────────────────────────────────────────────────────────
+  TRAV_SIDEWALK = 0
+  TRAV_GRASS    = 1
+  TRAV_ROAD     = 2
+  TRAV_OBSTACLE = 3
+  TRAV_UNKNOWN  = 4
+"""
+
+import numpy as np
+
+# ── Traversability class constants ────────────────────────────────────────────
+
+TRAV_SIDEWALK = 0
+TRAV_GRASS    = 1
+TRAV_ROAD     = 2
+TRAV_OBSTACLE = 3
+TRAV_UNKNOWN  = 4
+
+NUM_TRAV_CLASSES = 5
+
+# ── OccupancyGrid cost values for each traversability class ───────────────────
+# Nav2 OccupancyGrid: 0=free, 1-99=cost, 100=lethal, -1=unknown
+
+TRAV_TO_COST = {
+    TRAV_SIDEWALK: 0,     # free — preferred surface
+    TRAV_GRASS:    50,    # medium cost — traversable but non-preferred
+    TRAV_ROAD:     90,    # high cost — avoid but can cross
+    TRAV_OBSTACLE: 100,   # lethal — never enter
+    TRAV_UNKNOWN:  -1,    # unknown — Nav2 treats as unknown cell
+}
+
+# ── Cityscapes 19-class → traversability lookup table ─────────────────────────
+# Index = Cityscapes training ID (0–18)
+
+_CITYSCAPES_TO_TRAV = np.array([
+    TRAV_ROAD,      # 0  road
+    TRAV_SIDEWALK,  # 1  sidewalk
+    TRAV_OBSTACLE,  # 2  building
+    TRAV_OBSTACLE,  # 3  wall
+    TRAV_OBSTACLE,  # 4  fence
+    TRAV_OBSTACLE,  # 5  pole
+    TRAV_OBSTACLE,  # 6  traffic light
+    TRAV_OBSTACLE,  # 7  traffic sign
+    TRAV_GRASS,     # 8  vegetation
+    TRAV_GRASS,     # 9  terrain
+    TRAV_UNKNOWN,   # 10 sky
+    TRAV_OBSTACLE,  # 11 person
+    TRAV_OBSTACLE,  # 12 rider
+    TRAV_OBSTACLE,  # 13 car
+    TRAV_OBSTACLE,  # 14 truck
+    TRAV_OBSTACLE,  # 15 bus
+    TRAV_OBSTACLE,  # 16 train
+    TRAV_OBSTACLE,  # 17 motorcycle
+    TRAV_OBSTACLE,  # 18 bicycle
+], dtype=np.uint8)
+
+# ── Visualisation colour map (BGR, for cv2.imshow / debug image) ──────────────
+# One colour per traversability class
+
+TRAV_COLORMAP_BGR = np.array([
+    [128, 64, 128],   # SIDEWALK  — purple
+    [152, 251, 152],  # GRASS     — pale green
+    [128,   0, 128],  # ROAD      — dark magenta
+    [ 60,  20, 220],  # OBSTACLE  — red-ish
+    [  0,   0,   0],  # UNKNOWN   — black
+], dtype=np.uint8)
+
+
+# ── Core mapping functions ────────────────────────────────────────────────────
+
+def cityscapes_to_traversability(mask: np.ndarray) -> np.ndarray:
+    """
+    Map a Cityscapes 19-class segmentation mask to traversability classes.
+
+    Parameters
+    ----------
+    mask : np.ndarray, shape (H, W), dtype uint8
+        Cityscapes class IDs in range [0, 18]. Values outside range are
+        mapped to TRAV_UNKNOWN.
+
+    Returns
+    -------
+    trav_mask : np.ndarray, shape (H, W), dtype uint8
+        Traversability class IDs in range [0, 4].
+    """
+    # Clamp out-of-range IDs to a safe default (unknown)
+    clipped = np.clip(mask.astype(np.int32), 0, len(_CITYSCAPES_TO_TRAV) - 1)
+    return _CITYSCAPES_TO_TRAV[clipped]
+
+
+def traversability_to_costmap(
+    trav_mask: np.ndarray,
+    unknown_as_obstacle: bool = False,
+) -> np.ndarray:
+    """
+    Convert a traversability mask to Nav2 OccupancyGrid int8 cost values.
+
+    Parameters
+    ----------
+    trav_mask : np.ndarray, shape (H, W), dtype uint8
+        Traversability class IDs (TRAV_* constants).
+    unknown_as_obstacle : bool
+        If True, TRAV_UNKNOWN cells are set to 100 (lethal) instead of -1.
+        Useful in dense urban environments where unknowns are likely walls.
+
+    Returns
+    -------
+    cost_map : np.ndarray, shape (H, W), dtype int8
+        OccupancyGrid cost values: 0=free, 1-99=cost, 100=lethal, -1=unknown.
+    """
+    H, W = trav_mask.shape
+    cost_map = np.full((H, W), -1, dtype=np.int8)
+
+    for trav_class, cost in TRAV_TO_COST.items():
+        if trav_class == TRAV_UNKNOWN and unknown_as_obstacle:
+            cost = 100
+        cost_map[trav_mask == trav_class] = cost
+
+    return cost_map
+
+
+def letterbox(
+    image: np.ndarray,
+    target_w: int,
+    target_h: int,
+    pad_value: int = 114,
+) -> tuple:
+    """
+    Letterbox-resize an image to (target_w, target_h) preserving aspect ratio.
+
+    Parameters
+    ----------
+    image : np.ndarray, shape (H, W, C), dtype uint8
+    target_w, target_h : int
+        Target width and height.
+    pad_value : int
+        Padding fill value.
+
+    Returns
+    -------
+    (canvas, scale, pad_left, pad_top) : tuple
+        canvas   : np.ndarray (target_h, target_w, C) — resized + padded image
+        scale    : float — scale factor applied (min of w_scale, h_scale)
+        pad_left : int — horizontal padding (pixels from left)
+        pad_top  : int — vertical padding (pixels from top)
+    """
+    import cv2  # lazy import — keeps module importable without cv2 in tests
+
+    src_h, src_w = image.shape[:2]
+    scale = min(target_w / src_w, target_h / src_h)
+    new_w = int(round(src_w * scale))
+    new_h = int(round(src_h * scale))
+
+    resized = cv2.resize(image, (new_w, new_h), interpolation=cv2.INTER_LINEAR)
+
+    pad_left = (target_w - new_w) // 2
+    pad_top  = (target_h - new_h) // 2
+
+    canvas = np.full((target_h, target_w, image.shape[2]), pad_value, dtype=np.uint8)
+    canvas[pad_top:pad_top + new_h, pad_left:pad_left + new_w] = resized
+
+    return canvas, scale, pad_left, pad_top
+
+
+def unpad_mask(
+    mask: np.ndarray,
+    orig_h: int,
+    orig_w: int,
+    scale: float,
+    pad_left: int,
+    pad_top: int,
+) -> np.ndarray:
+    """
+    Remove letterbox padding from a segmentation mask and resize to original.
+
+    Parameters
+    ----------
+    mask : np.ndarray, shape (target_h, target_w), dtype uint8
+        Segmentation output from model at letterboxed resolution.
+    orig_h, orig_w : int
+        Original image dimensions (before letterboxing).
+    scale, pad_left, pad_top : from letterbox()
+
+    Returns
+    -------
+    restored : np.ndarray, shape (orig_h, orig_w), dtype uint8
+    """
+    import cv2
+
+    new_h = int(round(orig_h * scale))
+    new_w = int(round(orig_w * scale))
+
+    cropped = mask[pad_top:pad_top + new_h, pad_left:pad_left + new_w]
+    restored = cv2.resize(cropped, (orig_w, orig_h), interpolation=cv2.INTER_NEAREST)
+    return restored
+
+
+def preprocess_for_inference(
+    image_bgr: np.ndarray,
+    input_w: int = 512,
+    input_h: int = 256,
+) -> tuple:
+    """
+    Preprocess a BGR image for BiSeNetV2 / DDRNet inference.
+
+    Applies letterboxing, BGR→RGB conversion, ImageNet normalisation,
+    HWC→NCHW layout, and float32 conversion.
+
+    Returns
+    -------
+    (blob, scale, pad_left, pad_top) : tuple
+        blob : np.ndarray (1, 3, input_h, input_w) float32 — model input
+        scale, pad_left, pad_top : for unpad_mask()
+    """
+    import cv2
+
+    canvas, scale, pad_left, pad_top = letterbox(image_bgr, input_w, input_h)
+
+    # BGR → RGB
+    rgb = cv2.cvtColor(canvas, cv2.COLOR_BGR2RGB)
+
+    # ImageNet normalisation
+    mean = np.array([0.485, 0.456, 0.406], dtype=np.float32)
+    std  = np.array([0.229, 0.224, 0.225], dtype=np.float32)
+    img  = rgb.astype(np.float32) / 255.0
+    img  = (img - mean) / std
+
+    # HWC → NCHW
+    blob = np.ascontiguousarray(img.transpose(2, 0, 1)[np.newaxis])
+
+    return blob, scale, pad_left, pad_top
+
+
+def colorise_traversability(trav_mask: np.ndarray) -> np.ndarray:
+    """
+    Convert traversability mask to an RGB visualisation image.
+
+    Returns
+    -------
+    vis : np.ndarray (H, W, 3) uint8 BGR — suitable for cv2.imshow / ROS Image
+    """
+    clipped = np.clip(trav_mask.astype(np.int32), 0, NUM_TRAV_CLASSES - 1)
+    return TRAV_COLORMAP_BGR[clipped]

jetson/ros2_ws/src/saltybot_segmentation/saltybot_segmentation/sidewalk_seg_node.py

@@ -0,0 +1,437 @@
+"""
+sidewalk_seg_node.py — Semantic sidewalk segmentation node for SaltyBot.
+
+Subscribes:
+  /camera/color/image_raw   (sensor_msgs/Image) — RealSense front RGB
+
+Publishes:
+  /segmentation/mask        (sensor_msgs/Image, mono8) — traversability class per pixel
+  /segmentation/costmap     (nav_msgs/OccupancyGrid)   — Nav2 traversability scores
+  /segmentation/debug_image (sensor_msgs/Image, bgr8)  — colour-coded visualisation
+
+Model backend (auto-selected, priority order)
+─────────────────────────────────────────────
+  1. TensorRT FP16 engine (.engine file)   — fastest, Orin GPU
+  2. ONNX Runtime (CUDA provider)          — fallback, still GPU
+  3. ONNX Runtime (CPU provider)           — last resort
+
+Build TRT engine:
+  python3 /opt/ros/humble/share/saltybot_segmentation/scripts/build_engine.py
+
+Supported model architectures
+──────────────────────────────
+  BiSeNetV2   — Cityscapes 72.6 mIoU, ~50fps @ 512×256 on Orin
+  DDRNet-23   — Cityscapes 79.5 mIoU, ~40fps @ 512×256 on Orin
+
+Performance target: >15fps at 512×256 on Jetson Orin Nano Super.
+
+Input:  512×256 RGB (letterboxed from 640×480 RealSense color)
+Output: 512×256 per-pixel traversability class ID (uint8)
+"""
+
+import threading
+import time
+
+import cv2
+import numpy as np
+import rclpy
+from cv_bridge import CvBridge
+from nav_msgs.msg import OccupancyGrid, MapMetaData
+from rclpy.node import Node
+from rclpy.qos import QoSProfile, ReliabilityPolicy, HistoryPolicy, DurabilityPolicy
+from sensor_msgs.msg import Image
+from std_msgs.msg import Header
+
+from saltybot_segmentation.seg_utils import (
+    cityscapes_to_traversability,
+    traversability_to_costmap,
+    preprocess_for_inference,
+    unpad_mask,
+    colorise_traversability,
+)
+
+# ── TensorRT backend ──────────────────────────────────────────────────────────
+
+try:
+    import tensorrt as trt
+    import pycuda.driver as cuda
+    import pycuda.autoinit  # noqa: F401 — initialises CUDA context
+    _TRT_AVAILABLE = True
+except ImportError:
+    _TRT_AVAILABLE = False
+
+
+class _TRTBackend:
+    """TensorRT FP16 inference backend."""
+
+    def __init__(self, engine_path: str, logger):
+        self._logger = logger
+        trt_logger = trt.Logger(trt.Logger.WARNING)
+        with open(engine_path, "rb") as f:
+            serialized = f.read()
+        runtime = trt.Runtime(trt_logger)
+        self._engine  = runtime.deserialize_cuda_engine(serialized)
+        self._context = self._engine.create_execution_context()
+        self._stream  = cuda.Stream()
+
+        # Allocate host + device buffers
+        self._bindings = []
+        self._host_in  = None
+        self._dev_in   = None
+        self._host_out = None
+        self._dev_out  = None
+
+        for i in range(self._engine.num_bindings):
+            shape = self._engine.get_binding_shape(i)
+            size  = int(np.prod(shape))
+            dtype = trt.nptype(self._engine.get_binding_dtype(i))
+            host_buf = cuda.pagelocked_empty(size, dtype)
+            dev_buf  = cuda.mem_alloc(host_buf.nbytes)
+            self._bindings.append(int(dev_buf))
+            if self._engine.binding_is_input(i):
+                self._host_in, self._dev_in = host_buf, dev_buf
+                self._in_shape = shape
+            else:
+                self._host_out, self._dev_out = host_buf, dev_buf
+                self._out_shape = shape
+
+        logger.info(f"TRT engine loaded: in={self._in_shape} out={self._out_shape}")
+
+    def infer(self, blob: np.ndarray) -> np.ndarray:
+        np.copyto(self._host_in, blob.ravel())
+        cuda.memcpy_htod_async(self._dev_in, self._host_in, self._stream)
+        self._context.execute_async_v2(self._bindings, self._stream.handle)
+        cuda.memcpy_dtoh_async(self._host_out, self._dev_out, self._stream)
+        self._stream.synchronize()
+        return self._host_out.reshape(self._out_shape)
+
+
+# ── ONNX Runtime backend ──────────────────────────────────────────────────────
+
+try:
+    import onnxruntime as ort
+    _ONNX_AVAILABLE = True
+except ImportError:
+    _ONNX_AVAILABLE = False
+
+
+class _ONNXBackend:
+    """ONNX Runtime inference backend (CUDA or CPU)."""
+
+    def __init__(self, onnx_path: str, logger):
+        providers = []
+        if _ONNX_AVAILABLE:
+            available = ort.get_available_providers()
+            if "CUDAExecutionProvider" in available:
+                providers.append("CUDAExecutionProvider")
+                logger.info("ONNX Runtime: using CUDA provider")
+            else:
+                logger.warn("ONNX Runtime: CUDA not available, falling back to CPU")
+            providers.append("CPUExecutionProvider")
+
+        self._session   = ort.InferenceSession(onnx_path, providers=providers)
+        self._input_name  = self._session.get_inputs()[0].name
+        self._output_name = self._session.get_outputs()[0].name
+        logger.info(f"ONNX model loaded: {onnx_path}")
+
+    def infer(self, blob: np.ndarray) -> np.ndarray:
+        return self._session.run([self._output_name], {self._input_name: blob})[0]
+
+
+# ── ROS2 Node ─────────────────────────────────────────────────────────────────
+
+class SidewalkSegNode(Node):
+
+    def __init__(self):
+        super().__init__("sidewalk_seg")
+
+        # ── Parameters ────────────────────────────────────────────────────────
+        self.declare_parameter("engine_path",
+            "/mnt/nvme/saltybot/models/bisenetv2_cityscapes_512x256.engine")
+        self.declare_parameter("onnx_path",
+            "/mnt/nvme/saltybot/models/bisenetv2_cityscapes_512x256.onnx")
+        self.declare_parameter("input_width",        512)
+        self.declare_parameter("input_height",       256)
+        self.declare_parameter("process_every_n",    2)     # skip frames to save GPU
+        self.declare_parameter("publish_debug_image", False)
+        self.declare_parameter("unknown_as_obstacle", False)
+        self.declare_parameter("costmap_resolution",  0.05)  # metres/cell
+        self.declare_parameter("costmap_range_m",     5.0)   # forward projection range
+        self.declare_parameter("camera_height_m",     0.15)  # RealSense mount height
+        self.declare_parameter("camera_pitch_deg",    0.0)   # tilt angle
+
+        self._p = self._load_params()
+
+        # ── Backend selection (TRT preferred) ──────────────────────────────────
+        self._backend = None
+        self._init_backend()
+
+        # ── Runtime state ─────────────────────────────────────────────────────
+        self._bridge        = CvBridge()
+        self._frame_count   = 0
+        self._last_mask     = None
+        self._last_mask_lock = threading.Lock()
+        self._t_infer        = 0.0
+
+        # ── QoS: sensor data (best-effort, keep-last=1) ────────────────────────
+        sensor_qos = QoSProfile(
+            reliability=ReliabilityPolicy.BEST_EFFORT,
+            history=HistoryPolicy.KEEP_LAST,
+            depth=1,
+        )
+        # Transient local for costmap (Nav2 expects this)
+        costmap_qos = QoSProfile(
+            reliability=ReliabilityPolicy.RELIABLE,
+            history=HistoryPolicy.KEEP_LAST,
+            depth=1,
+            durability=DurabilityPolicy.TRANSIENT_LOCAL,
+        )
+
+        # ── Subscriptions ─────────────────────────────────────────────────────
+        self.create_subscription(
+            Image, "/camera/color/image_raw", self._image_cb, sensor_qos)
+
+        # ── Publishers ────────────────────────────────────────────────────────
+        self._mask_pub  = self.create_publisher(Image, "/segmentation/mask",  10)
+        self._cost_pub  = self.create_publisher(
+            OccupancyGrid, "/segmentation/costmap", costmap_qos)
+        self._debug_pub = self.create_publisher(Image, "/segmentation/debug_image", 1)
+
+        self.get_logger().info(
+            f"SidewalkSeg ready  backend={'trt' if isinstance(self._backend, _TRTBackend) else 'onnx'} "
+            f"input={self._p['input_width']}x{self._p['input_height']} "
+            f"process_every={self._p['process_every_n']} frames"
+        )
+
+    # ── Helpers ────────────────────────────────────────────────────────────────
+
+    def _load_params(self) -> dict:
+        return {
+            "engine_path":        self.get_parameter("engine_path").value,
+            "onnx_path":          self.get_parameter("onnx_path").value,
+            "input_width":        self.get_parameter("input_width").value,
+            "input_height":       self.get_parameter("input_height").value,
+            "process_every_n":    self.get_parameter("process_every_n").value,
+            "publish_debug":      self.get_parameter("publish_debug_image").value,
+            "unknown_as_obstacle":self.get_parameter("unknown_as_obstacle").value,
+            "costmap_resolution": self.get_parameter("costmap_resolution").value,
+            "costmap_range_m":    self.get_parameter("costmap_range_m").value,
+            "camera_height_m":    self.get_parameter("camera_height_m").value,
+            "camera_pitch_deg":   self.get_parameter("camera_pitch_deg").value,
+        }
+
+    def _init_backend(self):
+        p = self._p
+        if _TRT_AVAILABLE:
+            import os
+            if os.path.exists(p["engine_path"]):
+                try:
+                    self._backend = _TRTBackend(p["engine_path"], self.get_logger())
+                    return
+                except Exception as e:
+                    self.get_logger().warn(f"TRT load failed: {e} — trying ONNX")
+
+        if _ONNX_AVAILABLE:
+            import os
+            if os.path.exists(p["onnx_path"]):
+                try:
+                    self._backend = _ONNXBackend(p["onnx_path"], self.get_logger())
+                    return
+                except Exception as e:
+                    self.get_logger().warn(f"ONNX load failed: {e}")
+
+        self.get_logger().warn(
+            "No inference backend available — node will publish empty masks. "
+            "Run build_engine.py to create the TRT engine."
+        )
+
+    # ── Image callback ─────────────────────────────────────────────────────────
+
+    def _image_cb(self, msg: Image):
+        self._frame_count += 1
+        if self._frame_count % self._p["process_every_n"] != 0:
+            return
+
+        try:
+            bgr = self._bridge.imgmsg_to_cv2(msg, desired_encoding="bgr8")
+        except Exception as e:
+            self.get_logger().warn(f"cv_bridge decode error: {e}")
+            return
+
+        orig_h, orig_w = bgr.shape[:2]
+        iw = self._p["input_width"]
+        ih = self._p["input_height"]
+
+        # ── Inference ─────────────────────────────────────────────────────────
+        if self._backend is not None:
+            try:
+                t0 = time.monotonic()
+                blob, scale, pad_l, pad_t = preprocess_for_inference(bgr, iw, ih)
+                raw = self._backend.infer(blob)
+                self._t_infer = time.monotonic() - t0
+
+                # raw shape: (1, num_classes, H, W) or (1, H, W)
+                if raw.ndim == 4:
+                    class_mask = raw[0].argmax(axis=0).astype(np.uint8)
+                else:
+                    class_mask = raw[0].astype(np.uint8)
+
+                # Unpad + restore to original resolution
+                class_mask_full = unpad_mask(
+                    class_mask, orig_h, orig_w, scale, pad_l, pad_t)
+
+                trav_mask = cityscapes_to_traversability(class_mask_full)
+
+            except Exception as e:
+                self.get_logger().warn(
+                    f"Inference error: {e}", throttle_duration_sec=5.0)
+                trav_mask = np.full((orig_h, orig_w), 4, dtype=np.uint8)  # all unknown
+        else:
+            trav_mask = np.full((orig_h, orig_w), 4, dtype=np.uint8)  # all unknown
+
+        with self._last_mask_lock:
+            self._last_mask = trav_mask
+
+        stamp = msg.header.stamp
+
+        # ── Publish segmentation mask ──────────────────────────────────────────
+        mask_msg = self._bridge.cv2_to_imgmsg(trav_mask, encoding="mono8")
+        mask_msg.header.stamp    = stamp
+        mask_msg.header.frame_id = "camera_color_optical_frame"
+        self._mask_pub.publish(mask_msg)
+
+        # ── Publish costmap ────────────────────────────────────────────────────
+        costmap_msg = self._build_costmap(trav_mask, stamp)
+        self._cost_pub.publish(costmap_msg)
+
+        # ── Debug visualisation ────────────────────────────────────────────────
+        if self._p["publish_debug"]:
+            vis = colorise_traversability(trav_mask)
+            debug_msg = self._bridge.cv2_to_imgmsg(vis, encoding="bgr8")
+            debug_msg.header.stamp    = stamp
+            debug_msg.header.frame_id = "camera_color_optical_frame"
+            self._debug_pub.publish(debug_msg)
+
+        if self._frame_count % 30 == 0:
+            fps_str = f"{1.0/self._t_infer:.1f} fps" if self._t_infer > 0 else "no inference"
+            self.get_logger().debug(
+                f"Seg frame {self._frame_count}: {fps_str}",
+                throttle_duration_sec=5.0,
+            )
+
+    # ── Costmap projection ─────────────────────────────────────────────────────
+
+    def _build_costmap(self, trav_mask: np.ndarray, stamp) -> OccupancyGrid:
+        """
+        Project the lower portion of the segmentation mask into a flat
+        OccupancyGrid in the base_link frame.
+
+        The projection uses a simple inverse-perspective ground model:
+          - Only pixels in the lower half of the image are projected
+            (upper half is unlikely to be ground plane in front of robot)
+          - Each pixel row maps to a forward distance using pinhole geometry
+            with the camera mount height and pitch angle.
+          - Columns map to lateral (Y) position via horizontal FOV.
+
+        The resulting OccupancyGrid covers [0, costmap_range_m] forward
+        and [-costmap_range_m/2, costmap_range_m/2] laterally in base_link.
+        """
+        p = self._p
+        res     = p["costmap_resolution"]    # metres per cell
+        rng     = p["costmap_range_m"]       # look-ahead range
+        cam_h   = p["camera_height_m"]
+        cam_pit = np.deg2rad(p["camera_pitch_deg"])
+
+        # Costmap grid dimensions
+        grid_h = int(rng / res)               # forward cells (X direction)
+        grid_w = int(rng / res)               # lateral cells (Y direction)
+        grid_cx = grid_w // 2                 # lateral centre cell
+
+        cost_map_int8 = traversability_to_costmap(
+            trav_mask,
+            unknown_as_obstacle=p["unknown_as_obstacle"],
+        )
+
+        img_h, img_w = trav_mask.shape
+        # Only process lower 60% of image (ground plane region)
+        row_start = int(img_h * 0.40)
+
+        # RealSense D435i approximate intrinsics at 640×480
+        # (horizontal FOV ~87°, vertical FOV ~58°)
+        fx = img_w / (2.0 * np.tan(np.deg2rad(87.0 / 2)))
+        fy = img_h / (2.0 * np.tan(np.deg2rad(58.0 / 2)))
+        cx = img_w / 2.0
+        cy = img_h / 2.0
+
+        # Output occupancy grid (init to -1 = unknown)
+        grid = np.full((grid_h, grid_w), -1, dtype=np.int8)
+
+        for row in range(row_start, img_h):
+            # Vertical angle from optical axis
+            alpha = np.arctan2(-(row - cy), fy) + cam_pit
+            if alpha >= 0:
+                continue  # ray points up — skip
+            # Ground distance from camera base (forward)
+            fwd_dist = cam_h / np.tan(-alpha)
+            if fwd_dist <= 0 or fwd_dist > rng:
+                continue
+
+            grid_row = int(fwd_dist / res)
+            if grid_row >= grid_h:
+                continue
+
+            for col in range(0, img_w):
+                # Lateral angle
+                beta = np.arctan2(col - cx, fx)
+                lat_dist = fwd_dist * np.tan(beta)
+
+                grid_col = grid_cx + int(lat_dist / res)
+                if grid_col < 0 or grid_col >= grid_w:
+                    continue
+
+                cell_cost = int(cost_map_int8[row, col])
+                existing  = int(grid[grid_row, grid_col])
+
+                # Max-cost merge: most conservative estimate wins
+                if existing < 0 or cell_cost > existing:
+                    grid[grid_row, grid_col] = np.int8(cell_cost)
+
+        # Build OccupancyGrid message
+        msg = OccupancyGrid()
+        msg.header.stamp    = stamp
+        msg.header.frame_id = "base_link"
+
+        msg.info = MapMetaData()
+        msg.info.resolution = res
+        msg.info.width      = grid_w
+        msg.info.height     = grid_h
+        msg.info.map_load_time = stamp
+
+        # Origin: lower-left corner in base_link
+        # Grid row 0 = closest (0m forward), row grid_h-1 = rng forward
+        # Grid col 0 = leftmost, col grid_cx = straight ahead
+        msg.info.origin.position.x = 0.0
+        msg.info.origin.position.y = -(rng / 2.0)
+        msg.info.origin.position.z = 0.0
+        msg.info.origin.orientation.w = 1.0
+
+        msg.data = grid.flatten().tolist()
+        return msg
+
+
+# ── Entry point ───────────────────────────────────────────────────────────────
+
+def main(args=None):
+    rclpy.init(args=args)
+    node = SidewalkSegNode()
+    try:
+        rclpy.spin(node)
+    except KeyboardInterrupt:
+        pass
+    finally:
+        node.destroy_node()
+        rclpy.try_shutdown()
+
+
+if __name__ == "__main__":
+    main()

jetson/ros2_ws/src/saltybot_segmentation/scripts/build_engine.py

@@ -0,0 +1,398 @@
+#!/usr/bin/env python3
+"""
+build_engine.py — Convert BiSeNetV2/DDRNet PyTorch model → ONNX → TensorRT FP16 engine.
+
+Run ONCE on the Jetson Orin Nano Super. The .engine file is hardware-specific
+(cannot be transferred between machines).
+
+Usage
+─────
+  # Build BiSeNetV2 engine (default, fastest):
+  python3 build_engine.py
+
+  # Build DDRNet-23-slim engine (higher mIoU, slightly slower):
+  python3 build_engine.py --model ddrnet
+
+  # Custom output paths:
+  python3 build_engine.py --onnx /tmp/model.onnx --engine /tmp/model.engine
+
+  # Re-export ONNX from local weights (skip download):
+  python3 build_engine.py --weights /path/to/bisenetv2.pth
+
+Prerequisites
+─────────────
+  pip install torch torchvision onnx onnxruntime-gpu
+  # TensorRT is pre-installed with JetPack 6 at /usr/lib/python3/dist-packages/tensorrt
+
+Outputs
+───────
+  /mnt/nvme/saltybot/models/bisenetv2_cityscapes_512x256.onnx    (FP32)
+  /mnt/nvme/saltybot/models/bisenetv2_cityscapes_512x256.engine  (TRT FP16)
+
+Model sources
+─────────────
+  BiSeNetV2 pretrained on Cityscapes:
+    https://github.com/CoinCheung/BiSeNet (MIT License)
+    Checkpoint: cp/model_final_v2_city.pth (~25MB)
+
+  DDRNet-23-slim pretrained on Cityscapes:
+    https://github.com/ydhongHIT/DDRNet (Apache License)
+    Checkpoint: DDRNet23s_imagenet.pth + Cityscapes fine-tune
+
+Performance on Orin Nano Super (1024-core Ampere, 20 TOPS)
+──────────────────────────────────────────────────────────
+  BiSeNetV2  FP32 ONNX:   ~12ms  (~83fps theoretical)
+  BiSeNetV2  FP16 TRT:    ~5ms   (~200fps theoretical, real ~50fps w/ overhead)
+  DDRNet-23  FP16 TRT:    ~8ms   (~125fps theoretical, real ~40fps)
+  Target:    >15fps including ROS2 overhead at 512×256
+"""
+
+import argparse
+import os
+import sys
+import time
+
+# ── Default paths ─────────────────────────────────────────────────────────────
+
+DEFAULT_MODEL_DIR = "/mnt/nvme/saltybot/models"
+INPUT_W, INPUT_H = 512, 256
+BATCH_SIZE = 1
+
+MODEL_CONFIGS = {
+    "bisenetv2": {
+        "onnx_name":   "bisenetv2_cityscapes_512x256.onnx",
+        "engine_name": "bisenetv2_cityscapes_512x256.engine",
+        "repo_url":    "https://github.com/CoinCheung/BiSeNet.git",
+        "weights_url": "https://github.com/CoinCheung/BiSeNet/releases/download/0.0.0/model_final_v2_city.pth",
+        "num_classes": 19,
+        "description": "BiSeNetV2 Cityscapes — 72.6 mIoU, ~50fps on Orin",
+    },
+    "ddrnet": {
+        "onnx_name":   "ddrnet23s_cityscapes_512x256.onnx",
+        "engine_name": "ddrnet23s_cityscapes_512x256.engine",
+        "repo_url":    "https://github.com/ydhongHIT/DDRNet.git",
+        "weights_url": None,  # must supply manually
+        "num_classes": 19,
+        "description": "DDRNet-23-slim Cityscapes — 79.5 mIoU, ~40fps on Orin",
+    },
+}
+
+
+def parse_args():
+    p = argparse.ArgumentParser(description="Build TensorRT segmentation engine")
+    p.add_argument("--model",   default="bisenetv2",
+                   choices=list(MODEL_CONFIGS.keys()),
+                   help="Model architecture")
+    p.add_argument("--weights", default=None,
+                   help="Path to .pth weights file (downloads if not set)")
+    p.add_argument("--onnx",    default=None, help="Output ONNX path")
+    p.add_argument("--engine",  default=None, help="Output TRT engine path")
+    p.add_argument("--fp32",    action="store_true",
+                   help="Build FP32 engine instead of FP16 (slower, more accurate)")
+    p.add_argument("--workspace-gb", type=float, default=2.0,
+                   help="TRT builder workspace in GB (default 2.0)")
+    p.add_argument("--skip-onnx", action="store_true",
+                   help="Skip ONNX export (use existing .onnx file)")
+    return p.parse_args()
+
+
+def ensure_dir(path: str):
+    os.makedirs(path, exist_ok=True)
+
+
+def download_weights(url: str, dest: str):
+    """Download model weights with progress display."""
+    import urllib.request
+    print(f"  Downloading weights from {url}")
+    print(f"  → {dest}")
+
+    def progress(count, block, total):
+        pct = min(count * block / total * 100, 100)
+        bar = "#" * int(pct / 2)
+        sys.stdout.write(f"\r  [{bar:<50}] {pct:.1f}%")
+        sys.stdout.flush()
+
+    urllib.request.urlretrieve(url, dest, reporthook=progress)
+    print()
+
+
+def export_bisenetv2_onnx(weights_path: str, onnx_path: str, num_classes: int = 19):
+    """
+    Export BiSeNetV2 from CoinCheung/BiSeNet to ONNX.
+
+    Expects BiSeNet repo to be cloned in /tmp/BiSeNet or PYTHONPATH set.
+    """
+    import torch
+
+    # Try to import BiSeNetV2 — clone repo if needed
+    try:
+        sys.path.insert(0, "/tmp/BiSeNet")
+        from lib.models.bisenetv2 import BiSeNetV2
+    except ImportError:
+        print("  Cloning BiSeNet repository to /tmp/BiSeNet ...")
+        os.system("git clone --depth 1 https://github.com/CoinCheung/BiSeNet.git /tmp/BiSeNet")
+        sys.path.insert(0, "/tmp/BiSeNet")
+        from lib.models.bisenetv2 import BiSeNetV2
+
+    print("  Loading BiSeNetV2 weights ...")
+    net = BiSeNetV2(num_classes)
+    state = torch.load(weights_path, map_location="cpu")
+    # Handle both direct state_dict and checkpoint wrapper
+    state_dict = state.get("state_dict", state.get("model", state))
+    # Strip module. prefix from DataParallel checkpoints
+    state_dict = {k.replace("module.", ""): v for k, v in state_dict.items()}
+    net.load_state_dict(state_dict, strict=False)
+    net.eval()
+
+    print(f"  Exporting ONNX → {onnx_path}")
+    dummy = torch.randn(BATCH_SIZE, 3, INPUT_H, INPUT_W)
+
+    import torch.onnx
+    # BiSeNetV2 inference returns (logits, *aux) — we only want logits
+    class _Wrapper(torch.nn.Module):
+        def __init__(self, net):
+            super().__init__()
+            self.net = net
+        def forward(self, x):
+            out = self.net(x)
+            return out[0] if isinstance(out, (list, tuple)) else out
+
+    wrapped = _Wrapper(net)
+    torch.onnx.export(
+        wrapped, dummy, onnx_path,
+        opset_version=12,
+        input_names=["image"],
+        output_names=["logits"],
+        dynamic_axes=None,  # fixed batch=1 for TRT
+        do_constant_folding=True,
+    )
+
+    # Verify
+    import onnx
+    model = onnx.load(onnx_path)
+    onnx.checker.check_model(model)
+    print(f"  ONNX export verified  ({os.path.getsize(onnx_path) / 1e6:.1f} MB)")
+
+
+def export_ddrnet_onnx(weights_path: str, onnx_path: str, num_classes: int = 19):
+    """Export DDRNet-23-slim to ONNX."""
+    import torch
+
+    try:
+        sys.path.insert(0, "/tmp/DDRNet/tools/../lib")
+        from models.ddrnet_23_slim import get_seg_model
+    except ImportError:
+        print("  Cloning DDRNet repository to /tmp/DDRNet ...")
+        os.system("git clone --depth 1 https://github.com/ydhongHIT/DDRNet.git /tmp/DDRNet")
+        sys.path.insert(0, "/tmp/DDRNet/lib")
+        from models.ddrnet_23_slim import get_seg_model
+
+    print("  Loading DDRNet weights ...")
+    net = get_seg_model(num_classes=num_classes)
+    net.load_state_dict(
+        {k.replace("module.", ""): v
+         for k, v in torch.load(weights_path, map_location="cpu").items()},
+        strict=False
+    )
+    net.eval()
+
+    print(f"  Exporting ONNX → {onnx_path}")
+    dummy = torch.randn(BATCH_SIZE, 3, INPUT_H, INPUT_W)
+    import torch.onnx
+    torch.onnx.export(
+        net, dummy, onnx_path,
+        opset_version=12,
+        input_names=["image"],
+        output_names=["logits"],
+        do_constant_folding=True,
+    )
+    import onnx
+    onnx.checker.check_model(onnx.load(onnx_path))
+    print(f"  ONNX export verified  ({os.path.getsize(onnx_path) / 1e6:.1f} MB)")
+
+
+def build_trt_engine(onnx_path: str, engine_path: str,
+                     fp16: bool = True, workspace_gb: float = 2.0):
+    """
+    Build a TensorRT engine from an ONNX model.
+
+    Uses explicit batch dimension (not implicit batch).
+    Enables FP16 mode by default (2× speedup on Orin Ampere vs FP32).
+    """
+    try:
+        import tensorrt as trt
+    except ImportError:
+        print("ERROR: TensorRT not found. Install JetPack 6 or:")
+        print("  pip install tensorrt  (x86 only)")
+        sys.exit(1)
+
+    logger = trt.Logger(trt.Logger.INFO)
+
+    print(f"\n  Building TRT engine ({'FP16' if fp16 else 'FP32'}) from: {onnx_path}")
+    print(f"  Output: {engine_path}")
+    print(f"  Workspace: {workspace_gb:.1f} GB")
+    print("  This may take 5–15 minutes on first build (layer calibration)...")
+
+    t0 = time.time()
+
+    builder = trt.Builder(logger)
+    network = builder.create_network(
+        1 << int(trt.NetworkDefinitionCreationFlag.EXPLICIT_BATCH)
+    )
+    parser  = trt.OnnxParser(network, logger)
+    config  = builder.create_builder_config()
+
+    # Workspace
+    config.set_memory_pool_limit(
+        trt.MemoryPoolType.WORKSPACE, int(workspace_gb * 1024**3)
+    )
+
+    # FP16 precision
+    if fp16 and builder.platform_has_fast_fp16:
+        config.set_flag(trt.BuilderFlag.FP16)
+        print("  FP16 mode enabled")
+    elif fp16:
+        print("  WARNING: FP16 not available on this platform, using FP32")
+
+    # Parse ONNX
+    with open(onnx_path, "rb") as f:
+        if not parser.parse(f.read()):
+            for i in range(parser.num_errors):
+                print(f"  ONNX parse error: {parser.get_error(i)}")
+            sys.exit(1)
+
+    print(f"  Network: {network.num_inputs} input(s), {network.num_outputs} output(s)")
+    inp = network.get_input(0)
+    print(f"  Input shape: {inp.shape}  dtype: {inp.dtype}")
+
+    # Build
+    serialized_engine = builder.build_serialized_network(network, config)
+    if serialized_engine is None:
+        print("ERROR: TRT engine build failed")
+        sys.exit(1)
+
+    with open(engine_path, "wb") as f:
+        f.write(serialized_engine)
+
+    elapsed = time.time() - t0
+    size_mb = os.path.getsize(engine_path) / 1e6
+    print(f"\n  Engine built in {elapsed:.1f}s  ({size_mb:.1f} MB)")
+    print(f"  Saved: {engine_path}")
+
+
+def validate_engine(engine_path: str):
+    """Run a dummy inference to confirm the engine works and measure latency."""
+    try:
+        import tensorrt as trt
+        import pycuda.driver as cuda
+        import pycuda.autoinit  # noqa
+        import numpy as np
+    except ImportError:
+        print("  Skipping validation (pycuda not available)")
+        return
+
+    print("\n  Validating engine with dummy input...")
+    trt_logger = trt.Logger(trt.Logger.WARNING)
+    with open(engine_path, "rb") as f:
+        engine = trt.Runtime(trt_logger).deserialize_cuda_engine(f.read())
+    ctx = engine.create_execution_context()
+    stream = cuda.Stream()
+
+    bindings = []
+    host_in = host_out = dev_in = dev_out = None
+    for i in range(engine.num_bindings):
+        shape = engine.get_binding_shape(i)
+        dtype = trt.nptype(engine.get_binding_dtype(i))
+        h_buf = cuda.pagelocked_empty(int(np.prod(shape)), dtype)
+        d_buf = cuda.mem_alloc(h_buf.nbytes)
+        bindings.append(int(d_buf))
+        if engine.binding_is_input(i):
+            host_in, dev_in = h_buf, d_buf
+            host_in[:] = np.random.randn(*shape).astype(dtype).ravel()
+        else:
+            host_out, dev_out = h_buf, d_buf
+
+    # Warm up
+    for _ in range(5):
+        cuda.memcpy_htod_async(dev_in, host_in, stream)
+        ctx.execute_async_v2(bindings, stream.handle)
+        cuda.memcpy_dtoh_async(host_out, dev_out, stream)
+        stream.synchronize()
+
+    # Benchmark
+    N = 20
+    t0 = time.time()
+    for _ in range(N):
+        cuda.memcpy_htod_async(dev_in, host_in, stream)
+        ctx.execute_async_v2(bindings, stream.handle)
+        cuda.memcpy_dtoh_async(host_out, dev_out, stream)
+        stream.synchronize()
+    elapsed_ms = (time.time() - t0) * 1000 / N
+
+    out_shape = engine.get_binding_shape(engine.num_bindings - 1)
+    print(f"  Output shape: {out_shape}")
+    print(f"  Inference latency: {elapsed_ms:.1f}ms ({1000/elapsed_ms:.1f} fps) [avg {N} runs]")
+    if elapsed_ms < 1000 / 15:
+        print("  PASS: target >15fps achieved")
+    else:
+        print(f"  WARNING: latency {elapsed_ms:.1f}ms > target {1000/15:.1f}ms")
+
+
+def main():
+    args = parse_args()
+    cfg = MODEL_CONFIGS[args.model]
+    print(f"\nBuilding TRT engine for: {cfg['description']}")
+
+    ensure_dir(DEFAULT_MODEL_DIR)
+
+    onnx_path   = args.onnx   or os.path.join(DEFAULT_MODEL_DIR, cfg["onnx_name"])
+    engine_path = args.engine or os.path.join(DEFAULT_MODEL_DIR, cfg["engine_name"])
+
+    # ── Step 1: Download weights if needed ────────────────────────────────────
+    if not args.skip_onnx:
+        weights_path = args.weights
+        if weights_path is None:
+            if cfg["weights_url"] is None:
+                print(f"ERROR: No weights URL for {args.model}. Supply --weights /path/to.pth")
+                sys.exit(1)
+            weights_path = os.path.join(DEFAULT_MODEL_DIR, f"{args.model}_cityscapes.pth")
+            if not os.path.exists(weights_path):
+                print("\nStep 1: Downloading pretrained weights")
+                download_weights(cfg["weights_url"], weights_path)
+            else:
+                print(f"\nStep 1: Using cached weights: {weights_path}")
+        else:
+            print(f"\nStep 1: Using provided weights: {weights_path}")
+
+        # ── Step 2: Export ONNX ────────────────────────────────────────────────
+        print(f"\nStep 2: Exporting {args.model.upper()} to ONNX ({INPUT_W}×{INPUT_H})")
+        if args.model == "bisenetv2":
+            export_bisenetv2_onnx(weights_path, onnx_path, cfg["num_classes"])
+        else:
+            export_ddrnet_onnx(weights_path, onnx_path, cfg["num_classes"])
+    else:
+        print(f"\nStep 1+2: Skipping ONNX export, using: {onnx_path}")
+        if not os.path.exists(onnx_path):
+            print(f"ERROR: ONNX file not found: {onnx_path}")
+            sys.exit(1)
+
+    # ── Step 3: Build TRT engine ───────────────────────────────────────────────
+    print(f"\nStep 3: Building TensorRT engine")
+    build_trt_engine(
+        onnx_path, engine_path,
+        fp16=not args.fp32,
+        workspace_gb=args.workspace_gb,
+    )
+
+    # ── Step 4: Validate ───────────────────────────────────────────────────────
+    print(f"\nStep 4: Validating engine")
+    validate_engine(engine_path)
+
+    print(f"\nDone. Engine: {engine_path}")
+    print("Start the node:")
+    print(f"  ros2 launch saltybot_segmentation sidewalk_segmentation.launch.py \\")
+    print(f"    engine_path:={engine_path}")
+
+
+if __name__ == "__main__":
+    main()

jetson/ros2_ws/src/saltybot_segmentation/scripts/fine_tune.py

@@ -0,0 +1,400 @@
+#!/usr/bin/env python3
+"""
+fine_tune.py — Fine-tune BiSeNetV2 on custom sidewalk data.
+
+Walk-and-label workflow:
+  1. Record a ROS2 bag while walking the route:
+       ros2 bag record /camera/color/image_raw -o sidewalk_route
+  2. Extract frames from the bag:
+       python3 fine_tune.py --extract-frames sidewalk_route/ --output-dir data/raw/ --every-n 5
+  3. Label 50+ frames in LabelMe (or CVAT):
+       labelme data/raw/  (save as JSON)
+  4. Convert labels to Cityscapes-format masks:
+       python3 fine_tune.py --convert-labels data/raw/ --output-dir data/labels/
+  5. Fine-tune:
+       python3 fine_tune.py --train --images data/raw/ --labels data/labels/ \
+           --weights /mnt/nvme/saltybot/models/bisenetv2_cityscapes.pth \
+           --output /mnt/nvme/saltybot/models/bisenetv2_custom.pth
+  6. Build new TRT engine:
+       python3 build_engine.py --weights /mnt/nvme/saltybot/models/bisenetv2_custom.pth
+
+LabelMe class names (must match exactly in labelme JSON):
+  sidewalk  → Cityscapes ID 1 → TRAV_SIDEWALK
+  road      → Cityscapes ID 0 → TRAV_ROAD
+  grass     → Cityscapes ID 8 → TRAV_GRASS (use 'vegetation')
+  obstacle  → Cityscapes ID 2 → TRAV_OBSTACLE (use 'building' for static)
+  person    → Cityscapes ID 11
+  car       → Cityscapes ID 13
+
+Requirements:
+  pip install torch torchvision albumentations labelme opencv-python
+"""
+
+import argparse
+import json
+import os
+import sys
+
+import numpy as np
+
+# ── Label → Cityscapes ID mapping for custom annotation ──────────────────────
+
+LABEL_TO_CITYSCAPES = {
+    "road":        0,
+    "sidewalk":    1,
+    "building":    2,
+    "wall":        3,
+    "fence":       4,
+    "pole":        5,
+    "traffic light": 6,
+    "traffic sign":  7,
+    "vegetation":  8,
+    "grass":       8,   # alias
+    "terrain":     9,
+    "sky":         10,
+    "person":      11,
+    "rider":       12,
+    "car":         13,
+    "truck":       14,
+    "bus":         15,
+    "train":       16,
+    "motorcycle":  17,
+    "bicycle":     18,
+    # saltybot-specific aliases
+    "kerb":        1,   # map kerb → sidewalk
+    "pavement":    1,   # British English
+    "path":        1,
+    "tarmac":      0,   # map tarmac → road
+    "shrub":       8,   # map shrub → vegetation
+}
+
+DEFAULT_CLASS = 255  # unlabelled pixels → ignore in loss
+
+
+def parse_args():
+    p = argparse.ArgumentParser(description="Fine-tune BiSeNetV2 on custom data")
+    p.add_argument("--extract-frames", metavar="BAG_DIR",
+                   help="Extract frames from a ROS2 bag")
+    p.add_argument("--output-dir",     default="data/raw",
+                   help="Output directory for extracted frames or converted labels")
+    p.add_argument("--every-n",        type=int, default=5,
+                   help="Extract every N-th frame from bag")
+    p.add_argument("--convert-labels", metavar="LABELME_DIR",
+                   help="Convert LabelMe JSON annotations to Cityscapes masks")
+    p.add_argument("--train",          action="store_true",
+                   help="Run fine-tuning loop")
+    p.add_argument("--images",         default="data/raw",
+                   help="Directory of training images")
+    p.add_argument("--labels",         default="data/labels",
+                   help="Directory of label masks (PNG, Cityscapes IDs)")
+    p.add_argument("--weights",        required=False,
+                   default="/mnt/nvme/saltybot/models/bisenetv2_cityscapes.pth",
+                   help="Path to pretrained BiSeNetV2 weights")
+    p.add_argument("--output",
+                   default="/mnt/nvme/saltybot/models/bisenetv2_custom.pth",
+                   help="Output path for fine-tuned weights")
+    p.add_argument("--epochs",         type=int, default=20)
+    p.add_argument("--lr",             type=float, default=1e-4)
+    p.add_argument("--batch-size",     type=int, default=4)
+    p.add_argument("--input-size",     nargs=2, type=int, default=[512, 256],
+                   help="Model input size: W H")
+    p.add_argument("--eval",           action="store_true",
+                   help="Evaluate mIoU on labelled data instead of training")
+    return p.parse_args()
+
+
+# ── Frame extraction from ROS2 bag ────────────────────────────────────────────
+
+def extract_frames(bag_dir: str, output_dir: str, every_n: int = 5):
+    """Extract /camera/color/image_raw frames from a ROS2 bag."""
+    try:
+        import rclpy
+        from rosbag2_py import SequentialReader, StorageOptions, ConverterOptions
+        from rclpy.serialization import deserialize_message
+        from sensor_msgs.msg import Image
+        from cv_bridge import CvBridge
+        import cv2
+    except ImportError:
+        print("ERROR: rosbag2_py / rclpy not available. Must run in ROS2 environment.")
+        sys.exit(1)
+
+    os.makedirs(output_dir, exist_ok=True)
+    bridge = CvBridge()
+
+    reader = SequentialReader()
+    reader.open(
+        StorageOptions(uri=bag_dir, storage_id="sqlite3"),
+        ConverterOptions("", ""),
+    )
+
+    topic = "/camera/color/image_raw"
+    count = 0
+    saved = 0
+
+    while reader.has_next():
+        topic_name, data, ts = reader.read_next()
+        if topic_name != topic:
+            continue
+        count += 1
+        if count % every_n != 0:
+            continue
+
+        msg = deserialize_message(data, Image)
+        bgr = bridge.imgmsg_to_cv2(msg, "bgr8")
+        fname = os.path.join(output_dir, f"frame_{ts:020d}.jpg")
+        cv2.imwrite(fname, bgr, [cv2.IMWRITE_JPEG_QUALITY, 95])
+        saved += 1
+        if saved % 10 == 0:
+            print(f"  Saved {saved} frames...")
+
+    print(f"Extracted {saved} frames from {count} total to {output_dir}")
+
+
+# ── LabelMe JSON → Cityscapes mask ───────────────────────────────────────────
+
+def convert_labelme_to_masks(labelme_dir: str, output_dir: str):
+    """Convert LabelMe polygon annotations to per-pixel Cityscapes-ID PNG masks."""
+    try:
+        import cv2
+    except ImportError:
+        print("ERROR: opencv-python not installed. pip install opencv-python")
+        sys.exit(1)
+
+    os.makedirs(output_dir, exist_ok=True)
+    json_files = [f for f in os.listdir(labelme_dir) if f.endswith(".json")]
+
+    if not json_files:
+        print(f"No .json annotation files found in {labelme_dir}")
+        sys.exit(1)
+
+    print(f"Converting {len(json_files)} annotation files...")
+    for jf in json_files:
+        with open(os.path.join(labelme_dir, jf)) as f:
+            anno = json.load(f)
+
+        h = anno["imageHeight"]
+        w = anno["imageWidth"]
+        mask = np.full((h, w), DEFAULT_CLASS, dtype=np.uint8)
+
+        for shape in anno.get("shapes", []):
+            label = shape["label"].lower().strip()
+            cid = LABEL_TO_CITYSCAPES.get(label)
+            if cid is None:
+                print(f"  WARNING: unknown label '{label}' in {jf} — skipping")
+                continue
+
+            pts = np.array(shape["points"], dtype=np.int32)
+            cv2.fillPoly(mask, [pts], cid)
+
+        out_name = os.path.splitext(jf)[0] + "_mask.png"
+        cv2.imwrite(os.path.join(output_dir, out_name), mask)
+
+    print(f"Masks saved to {output_dir}")
+
+
+# ── Training loop ─────────────────────────────────────────────────────────────
+
+def train(args):
+    """Fine-tune BiSeNetV2 with cross-entropy loss + ignore_index=255."""
+    try:
+        import torch
+        import torch.nn as nn
+        import torch.optim as optim
+        from torch.utils.data import Dataset, DataLoader
+        import cv2
+        import albumentations as A
+        from albumentations.pytorch import ToTensorV2
+    except ImportError as e:
+        print(f"ERROR: missing dependency — {e}")
+        print("pip install torch torchvision albumentations opencv-python")
+        sys.exit(1)
+
+    # -- Dataset ---------------------------------------------------------------
+    class SegDataset(Dataset):
+        def __init__(self, img_dir, lbl_dir, transform=None):
+            self.imgs = sorted([
+                os.path.join(img_dir, f)
+                for f in os.listdir(img_dir)
+                if f.endswith((".jpg", ".png"))
+            ])
+            self.lbls = sorted([
+                os.path.join(lbl_dir, f)
+                for f in os.listdir(lbl_dir)
+                if f.endswith(".png")
+            ])
+            if len(self.imgs) != len(self.lbls):
+                raise ValueError(
+                    f"Image/label count mismatch: {len(self.imgs)} vs {len(self.lbls)}"
+                )
+            self.transform = transform
+
+        def __len__(self): return len(self.imgs)
+
+        def __getitem__(self, idx):
+            img = cv2.cvtColor(cv2.imread(self.imgs[idx]), cv2.COLOR_BGR2RGB)
+            lbl = cv2.imread(self.lbls[idx], cv2.IMREAD_GRAYSCALE)
+            if self.transform:
+                aug = self.transform(image=img, mask=lbl)
+                img, lbl = aug["image"], aug["mask"]
+            return img, lbl.long()
+
+    iw, ih = args.input_size
+    transform = A.Compose([
+        A.Resize(ih, iw),
+        A.HorizontalFlip(p=0.5),
+        A.ColorJitter(brightness=0.3, contrast=0.3, saturation=0.3, hue=0.1, p=0.5),
+        A.Normalize(mean=(0.485, 0.456, 0.406), std=(0.229, 0.224, 0.225)),
+        ToTensorV2(),
+    ])
+
+    dataset = SegDataset(args.images, args.labels, transform=transform)
+    loader  = DataLoader(dataset, batch_size=args.batch_size, shuffle=True,
+                         num_workers=2, pin_memory=True)
+    print(f"Dataset: {len(dataset)} samples  batch={args.batch_size}")
+
+    # -- Model -----------------------------------------------------------------
+    sys.path.insert(0, "/tmp/BiSeNet")
+    try:
+        from lib.models.bisenetv2 import BiSeNetV2
+    except ImportError:
+        os.system("git clone --depth 1 https://github.com/CoinCheung/BiSeNet.git /tmp/BiSeNet")
+        from lib.models.bisenetv2 import BiSeNetV2
+
+    net = BiSeNetV2(n_classes=19)
+    state = torch.load(args.weights, map_location="cpu")
+    state_dict = state.get("state_dict", state.get("model", state))
+    state_dict = {k.replace("module.", ""): v for k, v in state_dict.items()}
+    net.load_state_dict(state_dict, strict=False)
+
+    device = "cuda" if torch.cuda.is_available() else "cpu"
+    net = net.to(device)
+    print(f"Training on: {device}")
+
+    # -- Optimiser (low LR to preserve Cityscapes knowledge) -------------------
+    optimiser = optim.AdamW(net.parameters(), lr=args.lr, weight_decay=1e-4)
+    scheduler = optim.lr_scheduler.CosineAnnealingLR(optimiser, T_max=args.epochs)
+    criterion = nn.CrossEntropyLoss(ignore_index=DEFAULT_CLASS)
+
+    # -- Loop ------------------------------------------------------------------
+    best_loss = float("inf")
+    for epoch in range(1, args.epochs + 1):
+        net.train()
+        total_loss = 0.0
+
+        for imgs, lbls in loader:
+            imgs = imgs.to(device, dtype=torch.float32)
+            lbls = lbls.to(device)
+
+            out = net(imgs)
+            logits = out[0] if isinstance(out, (list, tuple)) else out
+
+            loss = criterion(logits, lbls)
+            optimiser.zero_grad()
+            loss.backward()
+            optimiser.step()
+            total_loss += loss.item()
+
+        scheduler.step()
+        avg = total_loss / len(loader)
+        print(f"  Epoch {epoch:3d}/{args.epochs}  loss={avg:.4f}  lr={scheduler.get_last_lr()[0]:.2e}")
+
+        if avg < best_loss:
+            best_loss = avg
+            torch.save(net.state_dict(), args.output)
+            print(f"  Saved best model → {args.output}")
+
+    print(f"\nFine-tuning done. Best loss: {best_loss:.4f}  Saved: {args.output}")
+    print("\nNext step: rebuild TRT engine:")
+    print(f"  python3 build_engine.py --weights {args.output}")
+
+
+# ── mIoU evaluation ───────────────────────────────────────────────────────────
+
+def evaluate_miou(args):
+    """Compute mIoU on labelled validation data."""
+    try:
+        import torch
+        import cv2
+    except ImportError:
+        print("ERROR: torch/cv2 not available")
+        sys.exit(1)
+
+    from saltybot_segmentation.seg_utils import cityscapes_to_traversability
+
+    NUM_CLASSES = 19
+    confusion = np.zeros((NUM_CLASSES, NUM_CLASSES), dtype=np.int64)
+
+    sys.path.insert(0, "/tmp/BiSeNet")
+    from lib.models.bisenetv2 import BiSeNetV2
+    import torch
+
+    net = BiSeNetV2(n_classes=NUM_CLASSES)
+    state_dict = {k.replace("module.", ""): v
+                  for k, v in torch.load(args.weights, map_location="cpu").items()}
+    net.load_state_dict(state_dict, strict=False)
+    net.eval().cuda() if torch.cuda.is_available() else net.eval()
+    device = next(net.parameters()).device
+
+    iw, ih = args.input_size
+    img_files = sorted([f for f in os.listdir(args.images) if f.endswith((".jpg", ".png"))])
+    lbl_files = sorted([f for f in os.listdir(args.labels) if f.endswith(".png")])
+
+    from saltybot_segmentation.seg_utils import preprocess_for_inference, unpad_mask
+
+    with torch.no_grad():
+        for imgf, lblf in zip(img_files, lbl_files):
+            img = cv2.imread(os.path.join(args.images, imgf))
+            lbl = cv2.imread(os.path.join(args.labels, lblf), cv2.IMREAD_GRAYSCALE)
+            H, W = img.shape[:2]
+
+            blob, scale, pad_l, pad_t = preprocess_for_inference(img, iw, ih)
+            t_blob = torch.from_numpy(blob).to(device)
+            out = net(t_blob)
+            logits = out[0] if isinstance(out, (list, tuple)) else out
+            pred = logits[0].argmax(0).cpu().numpy().astype(np.uint8)
+            pred = unpad_mask(pred, H, W, scale, pad_l, pad_t)
+
+            valid = lbl != DEFAULT_CLASS
+            np.add.at(confusion, (lbl[valid].ravel(), pred[valid].ravel()), 1)
+
+    # Per-class IoU
+    iou_per_class = []
+    for c in range(NUM_CLASSES):
+        tp = confusion[c, c]
+        fp = confusion[:, c].sum() - tp
+        fn = confusion[c, :].sum() - tp
+        denom = tp + fp + fn
+        iou_per_class.append(tp / denom if denom > 0 else float("nan"))
+
+    valid_iou = [v for v in iou_per_class if not np.isnan(v)]
+    miou = np.mean(valid_iou)
+
+    CITYSCAPES_NAMES = ["road", "sidewalk", "building", "wall", "fence", "pole",
+                        "traffic light", "traffic sign", "vegetation", "terrain",
+                        "sky", "person", "rider", "car", "truck", "bus", "train",
+                        "motorcycle", "bicycle"]
+    print("\nmIoU per class:")
+    for i, (name, iou) in enumerate(zip(CITYSCAPES_NAMES, iou_per_class)):
+        marker = " *" if not np.isnan(iou) else ""
+        print(f"  {i:2d} {name:<16} {iou*100:5.1f}%{marker}")
+    print(f"\nmIoU: {miou*100:.2f}%  ({len(valid_iou)}/{NUM_CLASSES} classes present)")
+
+
+def main():
+    args = parse_args()
+
+    if args.extract_frames:
+        extract_frames(args.extract_frames, args.output_dir, args.every_n)
+    elif args.convert_labels:
+        convert_labelme_to_masks(args.convert_labels, args.output_dir)
+    elif args.eval:
+        evaluate_miou(args)
+    elif args.train:
+        train(args)
+    else:
+        print("Specify one of: --extract-frames, --convert-labels, --train, --eval")
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()

jetson/ros2_ws/src/saltybot_segmentation/setup.cfg

@@ -0,0 +1,4 @@
+[develop]
+script_dir=$base/lib/saltybot_segmentation
+[install]
+install_scripts=$base/lib/saltybot_segmentation

jetson/ros2_ws/src/saltybot_segmentation/setup.py

@@ -0,0 +1,36 @@
+from setuptools import setup
+import os
+from glob import glob
+
+package_name = "saltybot_segmentation"
+
+setup(
+    name=package_name,
+    version="0.1.0",
+    packages=[package_name],
+    data_files=[
+        ("share/ament_index/resource_index/packages",
+            ["resource/" + package_name]),
+        ("share/" + package_name, ["package.xml"]),
+        (os.path.join("share", package_name, "launch"),
+            glob("launch/*.py")),
+        (os.path.join("share", package_name, "config"),
+            glob("config/*.yaml")),
+        (os.path.join("share", package_name, "scripts"),
+            glob("scripts/*.py")),
+        (os.path.join("share", package_name, "docs"),
+            glob("docs/*.md")),
+    ],
+    install_requires=["setuptools"],
+    zip_safe=True,
+    maintainer="seb",
+    maintainer_email="seb@vayrette.com",
+    description="Semantic sidewalk segmentation for SaltyBot (BiSeNetV2/DDRNet TensorRT)",
+    license="MIT",
+    tests_require=["pytest"],
+    entry_points={
+        "console_scripts": [
+            "sidewalk_seg = saltybot_segmentation.sidewalk_seg_node:main",
+        ],
+    },
+)

jetson/ros2_ws/src/saltybot_segmentation/test/test_seg_utils.py

@@ -0,0 +1,168 @@
+"""
+test_seg_utils.py — Unit tests for seg_utils pure helpers.
+
+No ROS2 / TensorRT / cv2 runtime required — plain pytest with numpy.
+"""
+
+import numpy as np
+import pytest
+
+from saltybot_segmentation.seg_utils import (
+    TRAV_SIDEWALK, TRAV_GRASS, TRAV_ROAD, TRAV_OBSTACLE, TRAV_UNKNOWN,
+    TRAV_TO_COST,
+    cityscapes_to_traversability,
+    traversability_to_costmap,
+)
+
+
+# ── cityscapes_to_traversability ──────────────────────────────────────────────
+
+class TestCitiyscapesToTraversability:
+
+    def test_sidewalk_maps_to_free(self):
+        mask = np.array([[1]], dtype=np.uint8)  # Cityscapes: sidewalk
+        result = cityscapes_to_traversability(mask)
+        assert result[0, 0] == TRAV_SIDEWALK
+
+    def test_road_maps_to_road(self):
+        mask = np.array([[0]], dtype=np.uint8)  # Cityscapes: road
+        result = cityscapes_to_traversability(mask)
+        assert result[0, 0] == TRAV_ROAD
+
+    def test_vegetation_maps_to_grass(self):
+        mask = np.array([[8]], dtype=np.uint8)  # Cityscapes: vegetation
+        result = cityscapes_to_traversability(mask)
+        assert result[0, 0] == TRAV_GRASS
+
+    def test_terrain_maps_to_grass(self):
+        mask = np.array([[9]], dtype=np.uint8)  # Cityscapes: terrain
+        result = cityscapes_to_traversability(mask)
+        assert result[0, 0] == TRAV_GRASS
+
+    def test_building_maps_to_obstacle(self):
+        mask = np.array([[2]], dtype=np.uint8)  # Cityscapes: building
+        result = cityscapes_to_traversability(mask)
+        assert result[0, 0] == TRAV_OBSTACLE
+
+    def test_person_maps_to_obstacle(self):
+        mask = np.array([[11]], dtype=np.uint8)  # Cityscapes: person
+        result = cityscapes_to_traversability(mask)
+        assert result[0, 0] == TRAV_OBSTACLE
+
+    def test_car_maps_to_obstacle(self):
+        mask = np.array([[13]], dtype=np.uint8)  # Cityscapes: car
+        result = cityscapes_to_traversability(mask)
+        assert result[0, 0] == TRAV_OBSTACLE
+
+    def test_sky_maps_to_unknown(self):
+        mask = np.array([[10]], dtype=np.uint8)  # Cityscapes: sky
+        result = cityscapes_to_traversability(mask)
+        assert result[0, 0] == TRAV_UNKNOWN
+
+    def test_all_dynamic_obstacles_are_lethal(self):
+        # person=11, rider=12, car=13, truck=14, bus=15, train=16, motorcycle=17, bicycle=18
+        for cid in [11, 12, 13, 14, 15, 16, 17, 18]:
+            mask = np.array([[cid]], dtype=np.uint8)
+            result = cityscapes_to_traversability(mask)
+            assert result[0, 0] == TRAV_OBSTACLE, f"class {cid} should be OBSTACLE"
+
+    def test_all_static_obstacles_are_lethal(self):
+        # building=2, wall=3, fence=4, pole=5, traffic light=6, sign=7
+        for cid in [2, 3, 4, 5, 6, 7]:
+            mask = np.array([[cid]], dtype=np.uint8)
+            result = cityscapes_to_traversability(mask)
+            assert result[0, 0] == TRAV_OBSTACLE, f"class {cid} should be OBSTACLE"
+
+    def test_out_of_range_id_clamped(self):
+        """Class IDs beyond 18 should not crash — clamped to 18."""
+        mask = np.array([[200]], dtype=np.uint8)
+        result = cityscapes_to_traversability(mask)
+        assert result[0, 0] in range(5)  # valid traversability class
+
+    def test_multi_class_image(self):
+        """A 2×3 image with mixed classes maps correctly."""
+        mask = np.array([
+            [1, 0, 8],   # sidewalk, road, vegetation
+            [2, 11, 10], # building, person, sky
+        ], dtype=np.uint8)
+        result = cityscapes_to_traversability(mask)
+        assert result[0, 0] == TRAV_SIDEWALK
+        assert result[0, 1] == TRAV_ROAD
+        assert result[0, 2] == TRAV_GRASS
+        assert result[1, 0] == TRAV_OBSTACLE
+        assert result[1, 1] == TRAV_OBSTACLE
+        assert result[1, 2] == TRAV_UNKNOWN
+
+    def test_output_dtype_is_uint8(self):
+        mask = np.zeros((4, 4), dtype=np.uint8)
+        result = cityscapes_to_traversability(mask)
+        assert result.dtype == np.uint8
+
+    def test_output_shape_preserved(self):
+        mask = np.zeros((32, 64), dtype=np.uint8)
+        result = cityscapes_to_traversability(mask)
+        assert result.shape == (32, 64)
+
+
+# ── traversability_to_costmap ─────────────────────────────────────────────────
+
+class TestTraversabilityToCostmap:
+
+    def test_sidewalk_is_free(self):
+        mask = np.array([[TRAV_SIDEWALK]], dtype=np.uint8)
+        cost = traversability_to_costmap(mask)
+        assert cost[0, 0] == 0
+
+    def test_road_has_high_cost(self):
+        mask = np.array([[TRAV_ROAD]], dtype=np.uint8)
+        cost = traversability_to_costmap(mask)
+        assert 50 < cost[0, 0] < 100  # high but not lethal
+
+    def test_grass_has_medium_cost(self):
+        mask = np.array([[TRAV_GRASS]], dtype=np.uint8)
+        cost = traversability_to_costmap(mask)
+        grass_cost = TRAV_TO_COST[TRAV_GRASS]
+        assert cost[0, 0] == grass_cost
+        assert grass_cost < TRAV_TO_COST[TRAV_ROAD]  # grass < road cost
+
+    def test_obstacle_is_lethal(self):
+        mask = np.array([[TRAV_OBSTACLE]], dtype=np.uint8)
+        cost = traversability_to_costmap(mask)
+        assert cost[0, 0] == 100
+
+    def test_unknown_is_neg1_by_default(self):
+        mask = np.array([[TRAV_UNKNOWN]], dtype=np.uint8)
+        cost = traversability_to_costmap(mask)
+        assert cost[0, 0] == -1
+
+    def test_unknown_as_obstacle_flag(self):
+        mask = np.array([[TRAV_UNKNOWN]], dtype=np.uint8)
+        cost = traversability_to_costmap(mask, unknown_as_obstacle=True)
+        assert cost[0, 0] == 100
+
+    def test_cost_ordering(self):
+        """sidewalk < grass < road < obstacle."""
+        assert TRAV_TO_COST[TRAV_SIDEWALK] < TRAV_TO_COST[TRAV_GRASS]
+        assert TRAV_TO_COST[TRAV_GRASS]    < TRAV_TO_COST[TRAV_ROAD]
+        assert TRAV_TO_COST[TRAV_ROAD]     < TRAV_TO_COST[TRAV_OBSTACLE]
+
+    def test_output_dtype_is_int8(self):
+        mask = np.zeros((4, 4), dtype=np.uint8)
+        cost = traversability_to_costmap(mask)
+        assert cost.dtype == np.int8
+
+    def test_output_shape_preserved(self):
+        mask = np.zeros((16, 32), dtype=np.uint8)
+        cost = traversability_to_costmap(mask)
+        assert cost.shape == (16, 32)
+
+    def test_mixed_mask(self):
+        mask = np.array([
+            [TRAV_SIDEWALK, TRAV_ROAD],
+            [TRAV_OBSTACLE, TRAV_UNKNOWN],
+        ], dtype=np.uint8)
+        cost = traversability_to_costmap(mask)
+        assert cost[0, 0] == TRAV_TO_COST[TRAV_SIDEWALK]
+        assert cost[0, 1] == TRAV_TO_COST[TRAV_ROAD]
+        assert cost[1, 0] == TRAV_TO_COST[TRAV_OBSTACLE]
+        assert cost[1, 1] == -1  # unknown

jetson/ros2_ws/src/saltybot_segmentation_costmap/CMakeLists.txt

@@ -0,0 +1,70 @@
+cmake_minimum_required(VERSION 3.8)
+project(saltybot_segmentation_costmap)
+
+# Default to C++17
+if(NOT CMAKE_CXX_STANDARD)
+  set(CMAKE_CXX_STANDARD 17)
+endif()
+
+if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+  add_compile_options(-Wall -Wextra -Wpedantic)
+endif()
+
+# ── Dependencies ──────────────────────────────────────────────────────────────
+find_package(ament_cmake REQUIRED)
+find_package(rclcpp REQUIRED)
+find_package(nav2_costmap_2d REQUIRED)
+find_package(nav_msgs REQUIRED)
+find_package(pluginlib REQUIRED)
+
+# ── Shared library (the plugin) ───────────────────────────────────────────────
+add_library(${PROJECT_NAME} SHARED
+  src/segmentation_costmap_layer.cpp
+)
+
+target_include_directories(${PROJECT_NAME} PUBLIC
+  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+  $<INSTALL_INTERFACE:include>
+)
+
+ament_target_dependencies(${PROJECT_NAME}
+  rclcpp
+  nav2_costmap_2d
+  nav_msgs
+  pluginlib
+)
+
+# Export plugin XML
+pluginlib_export_plugin_description_file(nav2_costmap_2d plugin.xml)
+
+# ── Install ───────────────────────────────────────────────────────────────────
+install(TARGETS ${PROJECT_NAME}
+  ARCHIVE DESTINATION lib
+  LIBRARY DESTINATION lib
+  RUNTIME DESTINATION bin
+)
+
+install(DIRECTORY include/
+  DESTINATION include
+)
+
+install(FILES plugin.xml
+  DESTINATION share/${PROJECT_NAME}
+)
+
+# ── Tests ─────────────────────────────────────────────────────────────────────
+if(BUILD_TESTING)
+  find_package(ament_lint_auto REQUIRED)
+  ament_lint_auto_find_test_dependencies()
+endif()
+
+ament_export_include_directories(include)
+ament_export_libraries(${PROJECT_NAME})
+ament_export_dependencies(
+  rclcpp
+  nav2_costmap_2d
+  nav_msgs
+  pluginlib
+)
+
+ament_package()

jetson/ros2_ws/src/saltybot_segmentation_costmap/include/saltybot_segmentation_costmap/segmentation_costmap_layer.hpp

@@ -0,0 +1,85 @@
+#pragma once
+
+#include <mutex>
+#include <string>
+
+#include "nav2_costmap_2d/layer.hpp"
+#include "nav2_costmap_2d/layered_costmap.hpp"
+#include "nav_msgs/msg/occupancy_grid.hpp"
+#include "rclcpp/rclcpp.hpp"
+
+namespace saltybot_segmentation_costmap
+{
+
+/**
+ * SegmentationCostmapLayer
+ *
+ * Nav2 costmap2d plugin that subscribes to /segmentation/costmap
+ * (nav_msgs/OccupancyGrid published by sidewalk_seg_node) and merges
+ * traversability costs into the Nav2 local_costmap.
+ *
+ * Merging strategy (combination_method parameter):
+ *   "max"      — keep the higher cost between existing and new (default, conservative)
+ *   "override" — always write the new cost, replacing existing
+ *   "min"      — keep the lower cost (permissive)
+ *
+ * Cost mapping from OccupancyGrid int8 to Nav2 costmap uint8:
+ *   -1   (unknown) → not written (cell unchanged)
+ *   0    (free)    → FREE_SPACE (0)
+ *   1–99 (cost)    → scaled to Nav2 range [1, INSCRIBED_INFLATED_OBSTACLE-1]
+ *   100  (lethal)  → LETHAL_OBSTACLE (254)
+ *
+ * Add to Nav2 local_costmap params:
+ *   local_costmap:
+ *     plugins: ["voxel_layer", "inflation_layer", "segmentation_layer"]
+ *     segmentation_layer:
+ *       plugin: "saltybot_segmentation_costmap::SegmentationCostmapLayer"
+ *       enabled: true
+ *       topic: /segmentation/costmap
+ *       combination_method: max
+ *       max_obstacle_distance: 0.0   (use all cells)
+ */
+class SegmentationCostmapLayer : public nav2_costmap_2d::Layer
+{
+public:
+  SegmentationCostmapLayer();
+  ~SegmentationCostmapLayer() override = default;
+
+  void onInitialize() override;
+  void updateBounds(
+    double robot_x, double robot_y, double robot_yaw,
+    double * min_x, double * min_y,
+    double * max_x, double * max_y) override;
+  void updateCosts(
+    nav2_costmap_2d::Costmap2D & master_grid,
+    int min_i, int min_j, int max_i, int max_j) override;
+
+  void reset() override;
+  bool isClearable() override { return true; }
+
+private:
+  void segCostmapCallback(const nav_msgs::msg::OccupancyGrid::SharedPtr msg);
+
+  /**
+   * Map OccupancyGrid int8 value to Nav2 costmap uint8 cost.
+   *   -1  → leave unchanged (return false)
+   *   0   → FREE_SPACE (0)
+   *   1–99 → 1 to INSCRIBED_INFLATED_OBSTACLE-1 (linear scale)
+   *   100 → LETHAL_OBSTACLE (254)
+   */
+  static bool occupancyToCost(int8_t occ, unsigned char & cost_out);
+
+  rclcpp::Subscription<nav_msgs::msg::OccupancyGrid>::SharedPtr sub_;
+  nav_msgs::msg::OccupancyGrid::SharedPtr latest_grid_;
+  std::mutex grid_mutex_;
+
+  std::string topic_;
+  std::string combination_method_;  // "max", "override", "min"
+  bool        enabled_;
+
+  // Track dirty bounds for updateBounds()
+  double last_min_x_, last_min_y_, last_max_x_, last_max_y_;
+  bool   need_update_;
+};
+
+}  // namespace saltybot_segmentation_costmap

jetson/ros2_ws/src/saltybot_segmentation_costmap/package.xml

@@ -0,0 +1,27 @@
+<?xml version="1.0"?>
+<?xml-model href="http://download.ros.org/schema/package_format3.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?>
+<package format="3">
+  <name>saltybot_segmentation_costmap</name>
+  <version>0.1.0</version>
+  <description>
+    Nav2 costmap2d plugin: SegmentationCostmapLayer.
+    Merges semantic traversability scores from sidewalk_seg_node into
+    the Nav2 local_costmap — sidewalk free, road high-cost, obstacle lethal.
+  </description>
+  <maintainer email="seb@vayrette.com">seb</maintainer>
+  <license>MIT</license>
+
+  <buildtool_depend>ament_cmake</buildtool_depend>
+
+  <depend>rclcpp</depend>
+  <depend>nav2_costmap_2d</depend>
+  <depend>nav_msgs</depend>
+  <depend>pluginlib</depend>
+
+  <test_depend>ament_lint_auto</test_depend>
+  <test_depend>ament_lint_common</test_depend>
+
+  <export>
+    <build_type>ament_cmake</build_type>
+  </export>
+</package>

jetson/ros2_ws/src/saltybot_segmentation_costmap/plugin.xml

@@ -0,0 +1,13 @@
+<library path="saltybot_segmentation_costmap">
+  <class
+    name="saltybot_segmentation_costmap::SegmentationCostmapLayer"
+    type="saltybot_segmentation_costmap::SegmentationCostmapLayer"
+    base_class_type="nav2_costmap_2d::Layer">
+    <description>
+      Nav2 costmap layer that merges semantic traversability scores from
+      /segmentation/costmap (published by sidewalk_seg_node) into the
+      Nav2 local_costmap. Roads are high-cost, obstacles are lethal,
+      sidewalks are free.
+    </description>
+  </class>
+</library>

jetson/ros2_ws/src/saltybot_segmentation_costmap/src/segmentation_costmap_layer.cpp

@@ -0,0 +1,207 @@
+#include "saltybot_segmentation_costmap/segmentation_costmap_layer.hpp"
+
+#include <algorithm>
+#include <string>
+
+#include "nav2_costmap_2d/costmap_2d.hpp"
+#include "pluginlib/class_list_macros.hpp"
+
+PLUGINLIB_EXPORT_CLASS(
+  saltybot_segmentation_costmap::SegmentationCostmapLayer,
+  nav2_costmap_2d::Layer)
+
+namespace saltybot_segmentation_costmap
+{
+
+using nav2_costmap_2d::FREE_SPACE;
+using nav2_costmap_2d::LETHAL_OBSTACLE;
+using nav2_costmap_2d::INSCRIBED_INFLATED_OBSTACLE;
+using nav2_costmap_2d::NO_INFORMATION;
+
+SegmentationCostmapLayer::SegmentationCostmapLayer()
+: last_min_x_(-1e9), last_min_y_(-1e9),
+  last_max_x_(1e9),  last_max_y_(1e9),
+  need_update_(false)
+{}
+
+// ── onInitialize ─────────────────────────────────────────────────────────────
+
+void SegmentationCostmapLayer::onInitialize()
+{
+  auto node = node_.lock();
+  if (!node) {
+    throw std::runtime_error("SegmentationCostmapLayer: node handle expired");
+  }
+
+  declareParameter("enabled",            rclcpp::ParameterValue(true));
+  declareParameter("topic",              rclcpp::ParameterValue(std::string("/segmentation/costmap")));
+  declareParameter("combination_method", rclcpp::ParameterValue(std::string("max")));
+
+  enabled_            = node->get_parameter(name_ + "." + "enabled").as_bool();
+  topic_              = node->get_parameter(name_ + "." + "topic").as_string();
+  combination_method_ = node->get_parameter(name_ + "." + "combination_method").as_string();
+
+  RCLCPP_INFO(
+    node->get_logger(),
+    "SegmentationCostmapLayer: topic=%s method=%s",
+    topic_.c_str(), combination_method_.c_str());
+
+  // Transient local QoS to match the sidewalk_seg_node publisher
+  rclcpp::QoS qos(rclcpp::KeepLast(1));
+  qos.transient_local();
+  qos.reliable();
+
+  sub_ = node->create_subscription<nav_msgs::msg::OccupancyGrid>(
+    topic_, qos,
+    std::bind(
+      &SegmentationCostmapLayer::segCostmapCallback, this,
+      std::placeholders::_1));
+
+  current_ = true;
+}
+
+// ── Subscription callback ─────────────────────────────────────────────────────
+
+void SegmentationCostmapLayer::segCostmapCallback(
+  const nav_msgs::msg::OccupancyGrid::SharedPtr msg)
+{
+  std::lock_guard<std::mutex> lock(grid_mutex_);
+  latest_grid_ = msg;
+  need_update_ = true;
+}
+
+// ── updateBounds ──────────────────────────────────────────────────────────────
+
+void SegmentationCostmapLayer::updateBounds(
+  double /*robot_x*/, double /*robot_y*/, double /*robot_yaw*/,
+  double * min_x, double * min_y,
+  double * max_x, double * max_y)
+{
+  if (!enabled_) {return;}
+
+  std::lock_guard<std::mutex> lock(grid_mutex_);
+  if (!latest_grid_) {return;}
+
+  const auto & info = latest_grid_->info;
+  double ox = info.origin.position.x;
+  double oy = info.origin.position.y;
+  double gw = info.width  * info.resolution;
+  double gh = info.height * info.resolution;
+
+  last_min_x_ = ox;
+  last_min_y_ = oy;
+  last_max_x_ = ox + gw;
+  last_max_y_ = oy + gh;
+
+  *min_x = std::min(*min_x, last_min_x_);
+  *min_y = std::min(*min_y, last_min_y_);
+  *max_x = std::max(*max_x, last_max_x_);
+  *max_y = std::max(*max_y, last_max_y_);
+}
+
+// ── updateCosts ───────────────────────────────────────────────────────────────
+
+void SegmentationCostmapLayer::updateCosts(
+  nav2_costmap_2d::Costmap2D & master,
+  int min_i, int min_j, int max_i, int max_j)
+{
+  if (!enabled_) {return;}
+
+  std::lock_guard<std::mutex> lock(grid_mutex_);
+  if (!latest_grid_ || !need_update_) {return;}
+
+  const auto & info  = latest_grid_->info;
+  const auto & data  = latest_grid_->data;
+
+  float seg_res = info.resolution;
+  float seg_ox  = static_cast<float>(info.origin.position.x);
+  float seg_oy  = static_cast<float>(info.origin.position.y);
+  int   seg_w   = static_cast<int>(info.width);
+  int   seg_h   = static_cast<int>(info.height);
+
+  float master_res = static_cast<float>(master.getResolution());
+
+  // Iterate over the update window
+  for (int j = min_j; j < max_j; ++j) {
+    for (int i = min_i; i < max_i; ++i) {
+      // World coords of this master cell centre
+      double wx, wy;
+      master.mapToWorld(
+        static_cast<unsigned int>(i), static_cast<unsigned int>(j), wx, wy);
+
+      // Corresponding cell in segmentation grid
+      int seg_col = static_cast<int>((wx - seg_ox) / seg_res);
+      int seg_row = static_cast<int>((wy - seg_oy) / seg_res);
+
+      if (seg_col < 0 || seg_col >= seg_w ||
+          seg_row < 0 || seg_row >= seg_h) {
+        continue;
+      }
+
+      int seg_idx = seg_row * seg_w + seg_col;
+      if (seg_idx < 0 || seg_idx >= static_cast<int>(data.size())) {
+        continue;
+      }
+
+      int8_t occ = data[static_cast<size_t>(seg_idx)];
+      unsigned char new_cost = 0;
+      if (!occupancyToCost(occ, new_cost)) {
+        continue;  // unknown cell — leave master unchanged
+      }
+
+      unsigned char existing = master.getCost(
+        static_cast<unsigned int>(i), static_cast<unsigned int>(j));
+
+      unsigned char final_cost = existing;
+      if (combination_method_ == "override") {
+        final_cost = new_cost;
+      } else if (combination_method_ == "min") {
+        final_cost = std::min(existing, new_cost);
+      } else {
+        // "max" (default) — most conservative
+        final_cost = std::max(existing, new_cost);
+      }
+
+      master.setCost(
+        static_cast<unsigned int>(i), static_cast<unsigned int>(j),
+        final_cost);
+    }
+  }
+
+  need_update_ = false;
+}
+
+// ── reset ─────────────────────────────────────────────────────────────────────
+
+void SegmentationCostmapLayer::reset()
+{
+  std::lock_guard<std::mutex> lock(grid_mutex_);
+  latest_grid_.reset();
+  need_update_ = false;
+  current_ = true;
+}
+
+// ── occupancyToCost ───────────────────────────────────────────────────────────
+
+bool SegmentationCostmapLayer::occupancyToCost(int8_t occ, unsigned char & cost_out)
+{
+  if (occ < 0) {
+    return false;  // unknown — leave cell unchanged
+  }
+  if (occ == 0) {
+    cost_out = FREE_SPACE;
+    return true;
+  }
+  if (occ >= 100) {
+    cost_out = LETHAL_OBSTACLE;
+    return true;
+  }
+  // Scale 1–99 → 1 to (INSCRIBED_INFLATED_OBSTACLE-1) = 1 to 252
+  int scaled = 1 + static_cast<int>(
+    (occ - 1) * (INSCRIBED_INFLATED_OBSTACLE - 2) / 98.0f);
+  cost_out = static_cast<unsigned char>(
+    std::min(scaled, static_cast<int>(INSCRIBED_INFLATED_OBSTACLE - 1)));
+  return true;
+}
+
+}  // namespace saltybot_segmentation_costmap

jetson/ros2_ws/src/saltybot_speed_controller/config/speed_profiles.yaml

@@ -0,0 +1,96 @@
+# speed_profiles.yaml
+# Outdoor adaptive speed profiles for SaltyBot follow-me mode.
+#
+# Run with:
+#   ros2 launch saltybot_speed_controller outdoor_speed.launch.py
+#
+# IMPORTANT: This controller outputs /cmd_vel which feeds into cmd_vel_bridge
+# (PR #46). The bridge applies its own hard caps (max_linear_vel=0.5 m/s).
+# For outdoor/ride profiles you MUST re-launch cmd_vel_bridge with higher limits:
+#   ros2 launch saltybot_bridge cmd_vel_bridge.launch.py max_linear_vel:=8.0
+#
+# Data flow:
+#   person_follower → /cmd_vel_raw → [speed_controller] → /cmd_vel → cmd_vel_bridge → STM32
+
+# ── Controller ─────────────────────────────────────────────────────────────────
+control_rate:   50.0           # Hz — 50ms tick, same as cmd_vel_bridge
+input_topic:    /cmd_vel_raw   # Upstream cmd_vel source
+output_topic:   /cmd_vel       # Output to cmd_vel_bridge
+initial_profile: walk          # Start in safest profile until target velocity known
+
+# ── Profile selection ──────────────────────────────────────────────────────────
+# Hysteresis prevents rapid walk↔jog↔ride oscillation.
+# up_ticks: consecutive ticks above threshold before upgrading profile (50Hz → 5 = 100ms)
+# down_ticks: ticks below threshold before downgrading (50Hz → 15 = 300ms)
+#   Downgrade is slower (safety: prefer lower profile when uncertain)
+hysteresis_up_ticks:   5
+hysteresis_down_ticks: 15
+
+# ── Emergency stop ─────────────────────────────────────────────────────────────
+# Triggered when target stops suddenly:
+#   (a) target velocity drops below stop_vel_threshold, OR
+#   (b) target deceleration exceeds hard_stop_decel_threshold m/s²
+#
+# emergency_decel_mps2: how fast the robot decelerates to zero.
+# Conservative (0.5-1.0 m/s²) is safer for balance; too fast = tip-over.
+# At ride speed (8 m/s), 2.0 m/s² = 4 second stop distance ≈ 16m — acceptable.
+emergency_decel_mps2:       2.0    # m/s² — hard brake limit
+stop_vel_threshold:         0.4    # m/s  — target speed below this = stopped
+hard_stop_decel_threshold:  3.0    # m/s² — target decel above this = hard stop
+
+# ── GPS runaway protection ─────────────────────────────────────────────────────
+# If GPS speed > commanded_speed × runaway_factor AND GPS speed > 50% of
+# profile max, trigger emergency decel (catches downhill runaways).
+gps_runaway_factor:  1.5    # 1.5× commanded = runaway
+gps_timeout:         3.0    # s — ignore GPS if stale (tunnel, bridge)
+
+# ── UWB range ─────────────────────────────────────────────────────────────────
+uwb_range_field:  range    # JSON field name in /uwb/ranges messages
+uwb_timeout:      2.0      # s — use GPS-only profile if UWB stale
+
+# ── Speed profiles ─────────────────────────────────────────────────────────────
+# Each profile applies when estimated target velocity is in [0, target_vel_max].
+# Velocity limits are BEFORE cmd_vel_bridge caps (bridge must also be set high).
+#
+# Acceleration notes:
+#   - Balance robot needs time to adjust lean angle when speed changes.
+#   - accel_limit at RIDE (0.3 m/s²) means 0→8 m/s takes ~27s — intentionally slow.
+#   - Increase only after validating balance PID tuning at speed.
+#   - decel_limit can be slightly higher than accel_limit (braking > accelerating).
+
+walk:
+  # Person walking at 0–2 m/s (≈ 0–7 km/h)
+  max_linear_vel:   1.5     # m/s  (= 5.4 km/h)
+  max_angular_vel:  1.2     # rad/s
+  accel_limit:      0.6     # m/s²  — moderate, balance handles it
+  decel_limit:      1.0     # m/s²
+  target_vel_max:   2.0     # m/s  — target faster than this → upgrade to jog
+
+jog:
+  # Person jogging at 2–5 m/s (≈ 7–18 km/h)
+  max_linear_vel:   3.0     # m/s  (= 10.8 km/h)
+  max_angular_vel:  1.5     # rad/s
+  accel_limit:      0.5     # m/s²  — a bit gentler at higher speed
+  decel_limit:      0.8     # m/s²
+  target_vel_max:   5.0     # m/s  — target faster than this → upgrade to ride
+
+ride:
+  # Person on EUC at 5–15 m/s (≈ 18–54 km/h / 20–30 km/h typical follow-me)
+  max_linear_vel:   8.0     # m/s  (= 28.8 km/h)
+  max_angular_vel:  1.5     # rad/s — conservative for balance at speed
+  accel_limit:      0.3     # m/s²  — very gentle: balance dynamics change at 8 m/s
+  decel_limit:      0.5     # m/s²  — gradual stop from 8 m/s ≈ 16s / ~64m
+  target_vel_max:   15.0    # m/s  — cap; EUC max ~30 km/h = 8.3 m/s typical
+
+# ── Notes ─────────────────────────────────────────────────────────────────────
+# 1. To enable ride profile, the Jetson → STM32 cmd_vel_bridge must also be
+#    reconfigured: max_linear_vel=8.0, ramp_rate=500 → consider ramp_rate=150
+#    at ride speed (slower ramp = smoother balance).
+#
+# 2. The STM32 balance PID gains likely need retuning for ride speed. Expect
+#    increased sensitivity to pitch angle errors at 8 m/s vs 0.5 m/s.
+#
+# 3. Test sequence recommendation:
+#    - Validate walk profile on flat indoor surface first
+#    - Test jog profile in controlled outdoor space
+#    - Only enable ride profile after verified balance at jog speeds

jetson/ros2_ws/src/saltybot_speed_controller/launch/outdoor_speed.launch.py

@@ -0,0 +1,155 @@
+"""
+outdoor_speed.launch.py — Outdoor adaptive speed controller.
+
+Inserts SpeedControllerNode between the person_follower (/cmd_vel_raw)
+and cmd_vel_bridge (/cmd_vel), providing adaptive walk/jog/ride profiles
+with smooth acceleration curves and emergency deceleration.
+
+IMPORTANT: For ride profile (up to 8 m/s) you must ALSO re-launch
+cmd_vel_bridge with matching limits:
+  ros2 launch saltybot_bridge cmd_vel_bridge.launch.py max_linear_vel:=8.0
+
+Prerequisite node pipeline:
+  person_follower → /cmd_vel_raw → [speed_controller] → /cmd_vel → cmd_vel_bridge → STM32
+
+Usage:
+  # Defaults (walk profile initially, adapts via UWB + GPS):
+  ros2 launch saltybot_speed_controller outdoor_speed.launch.py
+
+  # Force ride profile limits from start:
+  ros2 launch saltybot_speed_controller outdoor_speed.launch.py initial_profile:=ride
+
+  # Tune jog profile max speed:
+  ros2 launch saltybot_speed_controller outdoor_speed.launch.py jog_max_vel:=4.0
+
+  # Gentle emergency decel (longer stop distance, safer for balance):
+  ros2 launch saltybot_speed_controller outdoor_speed.launch.py emergency_decel:=1.0
+
+  # Full outdoor follow-me pipeline (speed controller + person follower):
+  ros2 launch saltybot_speed_controller outdoor_speed.launch.py \
+      launch_person_follower:=true
+
+Topics:
+  /cmd_vel_raw           — Input (from person_follower or Nav2)
+  /cmd_vel               — Output (to cmd_vel_bridge)
+  /speed_controller/profile — Active profile + status (JSON String)
+  /gps/vel               — Ground truth speed input (from gps_driver_node)
+  /uwb/ranges            — Target range input (for velocity estimation)
+"""
+
+import os
+
+from ament_index_python.packages import get_package_share_directory
+from launch import LaunchDescription
+from launch.actions import DeclareLaunchArgument, IncludeLaunchDescription, OpaqueFunction
+from launch.launch_description_sources import PythonLaunchDescriptionSource
+from launch.substitutions import LaunchConfiguration
+from launch_ros.actions import Node
+
+
+def _launch_nodes(context, *args, **kwargs):
+    params_file = LaunchConfiguration("params_file").perform(context)
+
+    def _s(k): return LaunchConfiguration(k).perform(context)
+    def _f(k): return float(LaunchConfiguration(k).perform(context))
+    def _i(k): return int(LaunchConfiguration(k).perform(context))
+    def _b(k): return LaunchConfiguration(k).perform(context).lower() == "true"
+
+    inline_params = {
+        "control_rate":              _f("control_rate"),
+        "input_topic":               _s("input_topic"),
+        "initial_profile":           _s("initial_profile"),
+        "hysteresis_up_ticks":       _i("hysteresis_up_ticks"),
+        "hysteresis_down_ticks":     _i("hysteresis_down_ticks"),
+        "emergency_decel_mps2":      _f("emergency_decel"),
+        "stop_vel_threshold":        _f("stop_vel_threshold"),
+        "hard_stop_decel_threshold": _f("hard_stop_decel_threshold"),
+        "gps_runaway_factor":        _f("gps_runaway_factor"),
+        "gps_timeout":               _f("gps_timeout"),
+        "uwb_timeout":               _f("uwb_timeout"),
+        # Per-profile params
+        "walk.max_linear_vel":       _f("walk_max_vel"),
+        "walk.accel_limit":          _f("walk_accel"),
+        "walk.decel_limit":          _f("walk_decel"),
+        "jog.max_linear_vel":        _f("jog_max_vel"),
+        "jog.accel_limit":           _f("jog_accel"),
+        "jog.decel_limit":           _f("jog_decel"),
+        "ride.max_linear_vel":       _f("ride_max_vel"),
+        "ride.accel_limit":          _f("ride_accel"),
+        "ride.decel_limit":          _f("ride_decel"),
+    }
+    node_params = [params_file, inline_params] if params_file else [inline_params]
+
+    nodes = [
+        Node(
+            package="saltybot_speed_controller",
+            executable="speed_controller_node",
+            name="speed_controller",
+            output="screen",
+            parameters=node_params,
+        ),
+    ]
+
+    if _b("launch_person_follower"):
+        try:
+            follower_pkg = get_package_share_directory("saltybot_follower")
+            follower_launch = os.path.join(
+                follower_pkg, "launch", "person_follower.launch.py")
+            nodes.append(IncludeLaunchDescription(
+                PythonLaunchDescriptionSource(follower_launch),
+                launch_arguments={"cmd_vel_topic": "/cmd_vel_raw"}.items(),
+            ))
+        except Exception:
+            pass   # package not built yet — skip silently
+
+    return nodes
+
+
+def generate_launch_description():
+    pkg_share     = get_package_share_directory("saltybot_speed_controller")
+    default_params = os.path.join(pkg_share, "config", "speed_profiles.yaml")
+
+    return LaunchDescription([
+        DeclareLaunchArgument(
+            "params_file", default_value=default_params,
+            description="Full path to speed_profiles.yaml"),
+
+        # General
+        DeclareLaunchArgument("control_rate",       default_value="50.0"),
+        DeclareLaunchArgument("input_topic",         default_value="/cmd_vel_raw"),
+        DeclareLaunchArgument("initial_profile",     default_value="walk"),
+        DeclareLaunchArgument("hysteresis_up_ticks",  default_value="5"),
+        DeclareLaunchArgument("hysteresis_down_ticks",default_value="15"),
+        DeclareLaunchArgument("launch_person_follower", default_value="false",
+                              description="Also launch saltybot_follower with /cmd_vel_raw output"),
+
+        # Emergency
+        DeclareLaunchArgument("emergency_decel",          default_value="2.0",
+                              description="Emergency decel limit (m/s²)"),
+        DeclareLaunchArgument("stop_vel_threshold",       default_value="0.4"),
+        DeclareLaunchArgument("hard_stop_decel_threshold",default_value="3.0"),
+
+        # GPS runaway
+        DeclareLaunchArgument("gps_runaway_factor", default_value="1.5"),
+        DeclareLaunchArgument("gps_timeout",        default_value="3.0"),
+        DeclareLaunchArgument("uwb_timeout",        default_value="2.0"),
+
+        # Walk profile
+        DeclareLaunchArgument("walk_max_vel", default_value="1.5"),
+        DeclareLaunchArgument("walk_accel",   default_value="0.6"),
+        DeclareLaunchArgument("walk_decel",   default_value="1.0"),
+
+        # Jog profile
+        DeclareLaunchArgument("jog_max_vel",  default_value="3.0"),
+        DeclareLaunchArgument("jog_accel",    default_value="0.5"),
+        DeclareLaunchArgument("jog_decel",    default_value="0.8"),
+
+        # Ride profile
+        DeclareLaunchArgument("ride_max_vel", default_value="8.0",
+                              description="Max speed for EUC follow-me (m/s)"),
+        DeclareLaunchArgument("ride_accel",   default_value="0.3",
+                              description="Gentle accel — balance sensitive at 8 m/s"),
+        DeclareLaunchArgument("ride_decel",   default_value="0.5"),
+
+        OpaqueFunction(function=_launch_nodes),
+    ])

jetson/ros2_ws/src/saltybot_speed_controller/package.xml

@@ -0,0 +1,31 @@
+<?xml version="1.0"?>
+<?xml-model href="http://download.ros.org/schema/package_format3.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?>
+<package format="3">
+  <name>saltybot_speed_controller</name>
+  <version>0.1.0</version>
+  <description>
+    Outdoor adaptive speed controller for SaltyBot follow-me mode.
+    Inserts between person_follower (/cmd_vel_raw) and cmd_vel_bridge (/cmd_vel),
+    selecting walk/jog/ride profiles based on estimated target velocity (UWB + GPS),
+    applying smooth trapezoidal acceleration curves, GPS runaway protection,
+    and emergency deceleration for balance stability at speeds up to 8 m/s.
+  </description>
+  <maintainer email="sl-controls@saltylab.local">sl-controls</maintainer>
+  <license>MIT</license>
+
+  <depend>rclpy</depend>
+  <depend>geometry_msgs</depend>
+  <depend>sensor_msgs</depend>
+  <depend>std_msgs</depend>
+
+  <buildtool_depend>ament_python</buildtool_depend>
+
+  <test_depend>ament_copyright</test_depend>
+  <test_depend>ament_flake8</test_depend>
+  <test_depend>ament_pep257</test_depend>
+  <test_depend>python3-pytest</test_depend>
+
+  <export>
+    <build_type>ament_python</build_type>
+  </export>
+</package>

jetson/ros2_ws/src/saltybot_speed_controller/saltybot_speed_controller/speed_controller_node.py

@@ -0,0 +1,491 @@
+"""
+speed_controller_node.py — Outdoor adaptive speed controller for SaltyBot.
+
+Sits between upstream cmd_vel sources (person_follower, Nav2) and the
+cmd_vel_bridge (PR #46), providing:
+
+  • Adaptive speed profiles   (walk / jog / ride) selected from UWB target
+    velocity and GPS ground-truth speed
+  • Smooth acceleration curves (trapezoidal ramp) per profile, tuned for
+    balance stability at speed — more aggressive jerk at low speed, gentler
+    at ride speeds (EUC follow-me at 20-30 km/h)
+  • Emergency deceleration    when the target stops suddenly (detected via
+    UWB range acceleration and target velocity drop)
+  • GPS runaway protection    if GPS ground speed significantly overshoots
+    the commanded velocity (downhill, slippage)
+
+Data flow:
+  /cmd_vel_raw  (Twist)           — uncapped request from person_follower/Nav2
+  /gps/vel      (TwistStamped)    — robot ground-truth speed (GPS, 1 Hz)
+  /uwb/ranges   (String JSON)     — UWB range to target (for velocity estimate)
+       ↓
+  SpeedControllerNode
+       ↓
+  /cmd_vel      (Twist)           — smoothed, profile-capped output → cmd_vel_bridge
+
+Profiles
+────────
+  walk : ≤ 1.5 m/s  (person walking  0–2 m/s)
+  jog  : ≤ 3.0 m/s  (person jogging  2–5 m/s)
+  ride : ≤ 8.0 m/s  (person on EUC   5–15 m/s)
+
+Profile selection uses UWB-derived target velocity with hysteresis to avoid
+rapid switching. GPS ground speed provides a secondary confirmation and
+runaway guard.
+"""
+
+import collections
+import json
+import math
+import time
+
+import rclpy
+from rclpy.node import Node
+from geometry_msgs.msg import Twist, TwistStamped
+from std_msgs.msg import String
+
+
+# ── Pure control functions ────────────────────────────────────────────────────
+# Extracted here so unit tests run without a ROS2 runtime.
+
+# Profile name constants
+WALK = "walk"
+JOG  = "jog"
+RIDE = "ride"
+
+_PROFILE_ORDER = [WALK, JOG, RIDE]
+
+
+def estimate_target_velocity(prev_range: float, curr_range: float,
+                              dt: float, robot_gps_speed: float) -> float:
+    """
+    Estimate absolute target velocity from UWB range derivative + GPS.
+
+    When the robot follows a target:
+      range_rate = d(range)/dt  (positive = target moving away)
+      target_vel ≈ robot_gps_speed + range_rate
+
+    This gives a rough scalar speed suitable for profile classification.
+    Returns 0 if dt ≤ 0 or range values are invalid.
+    """
+    if dt <= 0 or prev_range <= 0 or curr_range <= 0:
+        return robot_gps_speed   # fall back to robot's own speed
+    range_rate = (curr_range - prev_range) / dt
+    return max(0.0, robot_gps_speed + range_rate)
+
+
+def select_profile(target_vel: float, profiles: dict,
+                   current_profile: str,
+                   hysteresis_up: int = 5,
+                   hysteresis_down: int = 10,
+                   _counters: dict = None) -> str:
+    """
+    Select speed profile with up/down hysteresis.
+
+    target_vel    : estimated target velocity (m/s)
+    profiles      : dict of profile_name → {target_vel_min, target_vel_max, ...}
+    current_profile: currently active profile
+    hysteresis_up : ticks before switching to a faster profile
+    hysteresis_down: ticks before switching to a slower profile
+
+    Returns the (possibly unchanged) profile name.
+
+    _counters is an internal mutable dict passed by the caller for state
+    (avoids making this a method). Pass {} on first call; reuse thereafter.
+    """
+    if _counters is None:
+        _counters = {}
+
+    # Determine which profile best fits the target velocity
+    desired = current_profile
+    for name in _PROFILE_ORDER:
+        p = profiles[name]
+        if target_vel <= p["target_vel_max"]:
+            desired = name
+            break
+    else:
+        desired = RIDE   # above all max → stay at highest
+
+    if desired == current_profile:
+        _counters.clear()
+        return current_profile
+
+    key = desired
+    _counters[key] = _counters.get(key, 0) + 1
+
+    idx_desired = _PROFILE_ORDER.index(desired)
+    idx_current = _PROFILE_ORDER.index(current_profile)
+    threshold   = hysteresis_up if idx_desired > idx_current else hysteresis_down
+
+    if _counters[key] >= threshold:
+        _counters.clear()
+        return desired
+    return current_profile
+
+
+def apply_accel_limit(current: float, target: float,
+                      accel_limit: float, decel_limit: float,
+                      dt: float) -> float:
+    """
+    Apply symmetric trapezoidal acceleration / deceleration limit.
+
+    current     : current velocity (m/s)
+    target      : desired velocity (m/s)
+    accel_limit : max acceleration (m/s²)
+    decel_limit : max deceleration (m/s²) — positive value
+    dt          : time step (s)
+
+    Returns new velocity, ramped toward target within the limits.
+    """
+    delta = target - current
+    # Decelerating = magnitude is decreasing (current and delta have opposite signs)
+    decelerating = (current > 0 and delta < 0) or (current < 0 and delta > 0)
+    limit = decel_limit if decelerating else accel_limit
+    if delta > 0:
+        step = min(delta,  limit * dt)
+    else:
+        step = max(delta, -limit * dt)
+    return current + step
+
+
+def limit_velocity(linear_x: float, angular_z: float,
+                   max_linear: float, max_angular: float) -> tuple:
+    """Hard-clamp linear and angular velocity to profile limits."""
+    lin = max(-max_linear,  min(max_linear,  linear_x))
+    ang = max(-max_angular, min(max_angular, angular_z))
+    return lin, ang
+
+
+def check_emergency_stop(target_vel: float, target_vel_prev: float,
+                         dt: float,
+                         stop_vel_threshold: float,
+                         hard_decel_threshold: float) -> bool:
+    """
+    Detect sudden target stop requiring emergency deceleration.
+
+    Triggers if:
+      (a) target velocity drops below stop_vel_threshold, OR
+      (b) target deceleration exceeds hard_decel_threshold (m/s²)
+
+    Returns True if emergency stop should be engaged.
+    """
+    if target_vel < stop_vel_threshold:
+        return True
+    if dt > 0:
+        target_decel = (target_vel_prev - target_vel) / dt   # positive = decelerating
+        if target_decel > hard_decel_threshold:
+            return True
+    return False
+
+
+def check_gps_runaway(gps_speed: float, cmd_vel: float,
+                      runaway_factor: float, profile_max: float) -> bool:
+    """
+    Detect GPS runaway: robot moving significantly faster than commanded.
+
+    Triggers if gps_speed > max(cmd_vel, 0.5) * runaway_factor
+    AND gps_speed > profile_max (not a sensor glitch on a stationary robot).
+    """
+    reference = max(abs(cmd_vel), 0.5)
+    return gps_speed > reference * runaway_factor and gps_speed > profile_max * 0.5
+
+
+def emergency_decel_step(current_vel: float, decel_limit: float, dt: float) -> float:
+    """Decelerate toward zero at emergency_decel_limit. Returns new velocity."""
+    if current_vel > 0:
+        return max(0.0, current_vel - decel_limit * dt)
+    if current_vel < 0:
+        return min(0.0, current_vel + decel_limit * dt)
+    return 0.0
+
+
+# ── Default profiles (overridable via YAML) ──────────────────────────────────
+
+DEFAULT_PROFILES = {
+    WALK: {
+        "max_linear_vel":   1.5,
+        "max_angular_vel":  1.2,
+        "accel_limit":      0.6,    # m/s²
+        "decel_limit":      1.0,    # m/s²
+        "target_vel_min":   0.0,
+        "target_vel_max":   2.0,
+    },
+    JOG: {
+        "max_linear_vel":   3.0,
+        "max_angular_vel":  1.5,
+        "accel_limit":      0.5,
+        "decel_limit":      0.8,
+        "target_vel_min":   2.0,
+        "target_vel_max":   5.0,
+    },
+    RIDE: {
+        "max_linear_vel":   8.0,
+        "max_angular_vel":  1.5,    # conservative for balance at speed
+        "accel_limit":      0.3,    # very gentle — balance needs time at 8 m/s
+        "decel_limit":      0.5,
+        "target_vel_min":   5.0,
+        "target_vel_max":   15.0,
+    },
+}
+
+
+# ── ROS2 Node ─────────────────────────────────────────────────────────────────
+
+class SpeedControllerNode(Node):
+
+    def __init__(self):
+        super().__init__("speed_controller")
+
+        # ── Parameters ────────────────────────────────────────────────────────
+        self.declare_parameter("control_rate",           50.0)
+        self.declare_parameter("input_topic",            "/cmd_vel_raw")
+        self.declare_parameter("output_topic",           "/cmd_vel")
+        self.declare_parameter("initial_profile",        WALK)
+
+        # Profile selection
+        self.declare_parameter("hysteresis_up_ticks",   5)
+        self.declare_parameter("hysteresis_down_ticks", 15)
+
+        # Emergency stop
+        self.declare_parameter("emergency_decel_mps2",       2.0)
+        self.declare_parameter("stop_vel_threshold",         0.4)    # m/s
+        self.declare_parameter("hard_stop_decel_threshold",  3.0)    # m/s²
+
+        # GPS runaway
+        self.declare_parameter("gps_runaway_factor",    1.5)   # 1.5× commanded
+        self.declare_parameter("gps_timeout",           3.0)   # s before ignoring GPS
+
+        # UWB range
+        self.declare_parameter("uwb_range_field",       "range")
+        self.declare_parameter("uwb_timeout",           2.0)
+
+        # Per-profile overrides (flat params, merged into DEFAULT_PROFILES)
+        for profile in _PROFILE_ORDER:
+            self.declare_parameter(f"{profile}.max_linear_vel",
+                                   DEFAULT_PROFILES[profile]["max_linear_vel"])
+            self.declare_parameter(f"{profile}.max_angular_vel",
+                                   DEFAULT_PROFILES[profile]["max_angular_vel"])
+            self.declare_parameter(f"{profile}.accel_limit",
+                                   DEFAULT_PROFILES[profile]["accel_limit"])
+            self.declare_parameter(f"{profile}.decel_limit",
+                                   DEFAULT_PROFILES[profile]["decel_limit"])
+            self.declare_parameter(f"{profile}.target_vel_max",
+                                   DEFAULT_PROFILES[profile]["target_vel_max"])
+
+        self._profiles = self._load_profiles()
+        self._p = {
+            "control_rate":              self.get_parameter("control_rate").value,
+            "hysteresis_up":             self.get_parameter("hysteresis_up_ticks").value,
+            "hysteresis_down":           self.get_parameter("hysteresis_down_ticks").value,
+            "emergency_decel":           self.get_parameter("emergency_decel_mps2").value,
+            "stop_vel_threshold":        self.get_parameter("stop_vel_threshold").value,
+            "hard_stop_decel_threshold": self.get_parameter("hard_stop_decel_threshold").value,
+            "gps_runaway_factor":        self.get_parameter("gps_runaway_factor").value,
+            "gps_timeout":               self.get_parameter("gps_timeout").value,
+            "uwb_range_field":           self.get_parameter("uwb_range_field").value,
+            "uwb_timeout":               self.get_parameter("uwb_timeout").value,
+        }
+        dt = 1.0 / self._p["control_rate"]
+
+        # ── State ─────────────────────────────────────────────────────────────
+        self._profile        = self.get_parameter("initial_profile").value
+        self._profile_counters: dict = {}
+        self._current_linear = 0.0   # smoothed output linear.x
+        self._current_angular= 0.0   # smoothed output angular.z
+        self._request_linear = 0.0   # latest /cmd_vel_raw linear.x
+        self._request_angular= 0.0   # latest /cmd_vel_raw angular.z
+        self._gps_speed      = 0.0   # magnitude from /gps/vel
+        self._gps_stamp      = 0.0   # monotonic time of last GPS
+        self._uwb_range      = 0.0   # latest range (m)
+        self._uwb_range_prev = 0.0
+        self._uwb_stamp      = 0.0
+        self._uwb_stamp_prev = 0.0
+        self._target_vel     = 0.0
+        self._target_vel_prev= 0.0
+        self._emergency      = False
+        self._dt             = dt
+
+        # History for runaway filter (last 3 GPS samples)
+        self._gps_history: collections.deque = collections.deque(maxlen=3)
+
+        # ── Subscriptions ─────────────────────────────────────────────────────
+        self.create_subscription(
+            Twist, self.get_parameter("input_topic").value,
+            self._cmd_raw_cb, 10)
+        self.create_subscription(
+            TwistStamped, "/gps/vel", self._gps_cb, 10)
+        self.create_subscription(
+            String, "/uwb/ranges", self._uwb_cb, 10)
+
+        # ── Publisher ──────────────────────────────────────────────────────────
+        self._cmd_pub = self.create_publisher(
+            Twist, self.get_parameter("output_topic").value, 10)
+        self._profile_pub = self.create_publisher(
+            String, "/speed_controller/profile", 10)
+
+        # ── Control timer ──────────────────────────────────────────────────────
+        self.create_timer(dt, self._control_cb)
+
+        self.get_logger().info(
+            f"SpeedController ready  profile={self._profile} "
+            f"rate={self._p['control_rate']}Hz  "
+            f"walk≤{self._profiles[WALK]['max_linear_vel']}m/s  "
+            f"jog≤{self._profiles[JOG]['max_linear_vel']}m/s  "
+            f"ride≤{self._profiles[RIDE]['max_linear_vel']}m/s")
+
+    def _load_profiles(self) -> dict:
+        """Merge ROS2 params into DEFAULT_PROFILES."""
+        import copy
+        profiles = copy.deepcopy(DEFAULT_PROFILES)
+        for name in _PROFILE_ORDER:
+            for field in ("max_linear_vel", "max_angular_vel", "accel_limit",
+                          "decel_limit", "target_vel_max"):
+                val = self.get_parameter(f"{name}.{field}").value
+                profiles[name][field] = val
+        return profiles
+
+    # ── Callbacks ─────────────────────────────────────────────────────────────
+
+    def _cmd_raw_cb(self, msg: Twist):
+        self._request_linear  = msg.linear.x
+        self._request_angular = msg.angular.z
+
+    def _gps_cb(self, msg: TwistStamped):
+        vx = msg.twist.linear.x
+        vy = msg.twist.linear.y
+        self._gps_speed = math.sqrt(vx * vx + vy * vy)
+        self._gps_stamp = time.monotonic()
+        self._gps_history.append(self._gps_speed)
+
+    def _uwb_cb(self, msg: String):
+        """Parse JSON range message, update range estimate."""
+        try:
+            data = json.loads(msg.data)
+            field = self._p["uwb_range_field"]
+            r = float(data.get(field, data.get("distance", 0.0)))
+            if r > 0:
+                self._uwb_range_prev = self._uwb_range
+                self._uwb_stamp_prev = self._uwb_stamp
+                self._uwb_range      = r
+                self._uwb_stamp      = time.monotonic()
+        except (json.JSONDecodeError, ValueError, KeyError):
+            pass
+
+    # ── Control loop ──────────────────────────────────────────────────────────
+
+    def _control_cb(self):
+        now = time.monotonic()
+        dt  = self._dt
+
+        # ── 1. Estimate target velocity from UWB range derivative + GPS ──────
+        uwb_fresh = (now - self._uwb_stamp) < self._p["uwb_timeout"]
+        gps_fresh = (now - self._gps_stamp) < self._p["gps_timeout"]
+
+        if uwb_fresh and self._uwb_stamp_prev > 0:
+            uwb_dt = self._uwb_stamp - self._uwb_stamp_prev
+            robot_speed = self._gps_speed if gps_fresh else self._current_linear
+            self._target_vel_prev = self._target_vel
+            self._target_vel = estimate_target_velocity(
+                self._uwb_range_prev, self._uwb_range, uwb_dt, robot_speed)
+        elif gps_fresh:
+            # No UWB — use GPS speed as proxy for target velocity
+            self._target_vel_prev = self._target_vel
+            self._target_vel = self._gps_speed
+        # else: hold previous estimate
+
+        # ── 2. Profile selection ──────────────────────────────────────────────
+        self._profile = select_profile(
+            self._target_vel, self._profiles, self._profile,
+            self._p["hysteresis_up"], self._p["hysteresis_down"],
+            self._profile_counters,
+        )
+        prof = self._profiles[self._profile]
+
+        # ── 3. Emergency stop detection ───────────────────────────────────────
+        emerg = check_emergency_stop(
+            self._target_vel, self._target_vel_prev, dt,
+            self._p["stop_vel_threshold"],
+            self._p["hard_stop_decel_threshold"],
+        )
+        # GPS runaway check (use smoothed GPS)
+        if gps_fresh:
+            gps_smooth = sum(self._gps_history) / len(self._gps_history)
+            if check_gps_runaway(
+                    gps_smooth, self._current_linear,
+                    self._p["gps_runaway_factor"],
+                    prof["max_linear_vel"]):
+                emerg = True
+                self.get_logger().warn(
+                    f"GPS runaway: gps={gps_smooth:.2f} "
+                    f"cmd={self._current_linear:.2f} m/s — emergency decel",
+                    throttle_duration_sec=2.0)
+
+        # Latch emergency; clear when speed reaches zero
+        if emerg and not self._emergency:
+            self.get_logger().warn(
+                f"Emergency stop: target_vel={self._target_vel:.2f} m/s "
+                f"(profile={self._profile})")
+        self._emergency = emerg or (
+            self._emergency and abs(self._current_linear) > 0.05)
+
+        # ── 4. Compute target command ─────────────────────────────────────────
+        if self._emergency:
+            # Override request: decelerate to zero at emergency rate
+            target_lin = 0.0
+            target_ang = 0.0
+            new_lin = emergency_decel_step(
+                self._current_linear, self._p["emergency_decel"], dt)
+            new_ang = emergency_decel_step(
+                self._current_angular, self._p["emergency_decel"] * 2.0, dt)
+        else:
+            # Apply profile caps to request
+            target_lin, target_ang = limit_velocity(
+                self._request_linear, self._request_angular,
+                prof["max_linear_vel"], prof["max_angular_vel"])
+            # Apply smooth acceleration / deceleration
+            new_lin = apply_accel_limit(
+                self._current_linear,  target_lin,
+                prof["accel_limit"], prof["decel_limit"], dt)
+            new_ang = apply_accel_limit(
+                self._current_angular, target_ang,
+                prof["accel_limit"] * 2.0,   # angular can be snappier
+                prof["decel_limit"] * 2.0, dt)
+
+        self._current_linear  = new_lin
+        self._current_angular = new_ang
+
+        # ── 5. Publish ────────────────────────────────────────────────────────
+        out = Twist()
+        out.linear.x  = self._current_linear
+        out.angular.z = self._current_angular
+        self._cmd_pub.publish(out)
+
+        # Profile status (for dashboard / logging)
+        status = String()
+        status.data = json.dumps({
+            "profile":      self._profile,
+            "max_vel":      prof["max_linear_vel"],
+            "target_vel":   round(self._target_vel, 2),
+            "gps_speed":    round(self._gps_speed, 2),
+            "cmd_linear":   round(new_lin, 3),
+            "emergency":    self._emergency,
+        })
+        self._profile_pub.publish(status)
+
+
+# ── Entry point ───────────────────────────────────────────────────────────────
+
+def main(args=None):
+    rclpy.init(args=args)
+    node = SpeedControllerNode()
+    try:
+        rclpy.spin(node)
+    except KeyboardInterrupt:
+        pass
+    finally:
+        node.destroy_node()
+        rclpy.try_shutdown()
+
+
+if __name__ == "__main__":
+    main()

jetson/ros2_ws/src/saltybot_speed_controller/setup.cfg

@@ -0,0 +1,4 @@
+[develop]
+script_dir=$base/lib/saltybot_speed_controller
+[install]
+install_scripts=$base/lib/saltybot_speed_controller

jetson/ros2_ws/src/saltybot_speed_controller/setup.py

@@ -0,0 +1,31 @@
+from setuptools import setup
+
+package_name = "saltybot_speed_controller"
+
+setup(
+    name=package_name,
+    version="0.1.0",
+    packages=[package_name],
+    data_files=[
+        ("share/ament_index/resource_index/packages", [f"resource/{package_name}"]),
+        (f"share/{package_name}", ["package.xml"]),
+        (f"share/{package_name}/launch", ["launch/outdoor_speed.launch.py"]),
+        (f"share/{package_name}/config", ["config/speed_profiles.yaml"]),
+    ],
+    install_requires=["setuptools"],
+    zip_safe=True,
+    maintainer="sl-controls",
+    maintainer_email="sl-controls@saltylab.local",
+    description=(
+        "Outdoor adaptive speed controller: walk/jog/ride profiles "
+        "with trapezoidal accel limits and GPS runaway protection"
+    ),
+    license="MIT",
+    tests_require=["pytest"],
+    entry_points={
+        "console_scripts": [
+            # Adaptive speed profile node: /cmd_vel_raw → /cmd_vel
+            "speed_controller_node = saltybot_speed_controller.speed_controller_node:main",
+        ],
+    },
+)

jetson/ros2_ws/src/saltybot_speed_controller/test/test_speed_controller.py

@@ -0,0 +1,428 @@
+"""
+Unit tests for speed_controller_node pure functions.
+No ROS2 runtime required.
+Run with: pytest jetson/ros2_ws/src/saltybot_speed_controller/test/test_speed_controller.py
+"""
+
+import pytest
+
+# ── Pure function mirrors ─────────────────────────────────────────────────────
+
+WALK = "walk"
+JOG  = "jog"
+RIDE = "ride"
+_PROFILE_ORDER = [WALK, JOG, RIDE]
+
+_PROFILES = {
+    WALK: {"max_linear_vel": 1.5, "max_angular_vel": 1.2,
+           "accel_limit": 0.6,  "decel_limit": 1.0,
+           "target_vel_min": 0.0, "target_vel_max": 2.0},
+    JOG:  {"max_linear_vel": 3.0, "max_angular_vel": 1.5,
+           "accel_limit": 0.5,  "decel_limit": 0.8,
+           "target_vel_min": 2.0, "target_vel_max": 5.0},
+    RIDE: {"max_linear_vel": 8.0, "max_angular_vel": 1.5,
+           "accel_limit": 0.3,  "decel_limit": 0.5,
+           "target_vel_min": 5.0, "target_vel_max": 15.0},
+}
+
+
+def _estimate_target_velocity(prev_range, curr_range, dt, robot_gps_speed):
+    if dt <= 0 or prev_range <= 0 or curr_range <= 0:
+        return robot_gps_speed
+    range_rate = (curr_range - prev_range) / dt
+    return max(0.0, robot_gps_speed + range_rate)
+
+
+def _select_profile(target_vel, profiles, current_profile,
+                    hysteresis_up=5, hysteresis_down=10, counters=None):
+    if counters is None:
+        counters = {}
+    desired = current_profile
+    for name in _PROFILE_ORDER:
+        if target_vel <= profiles[name]["target_vel_max"]:
+            desired = name
+            break
+    else:
+        desired = RIDE
+    if desired == current_profile:
+        counters.clear()
+        return current_profile
+    key = desired
+    counters[key] = counters.get(key, 0) + 1
+    idx_d = _PROFILE_ORDER.index(desired)
+    idx_c = _PROFILE_ORDER.index(current_profile)
+    threshold = hysteresis_up if idx_d > idx_c else hysteresis_down
+    if counters[key] >= threshold:
+        counters.clear()
+        return desired
+    return current_profile
+
+
+def _apply_accel_limit(current, target, accel_limit, decel_limit, dt):
+    delta = target - current
+    # Decelerating = magnitude is decreasing (current and delta have opposite signs)
+    decelerating = (current > 0 and delta < 0) or (current < 0 and delta > 0)
+    limit = decel_limit if decelerating else accel_limit
+    if delta > 0:
+        step = min(delta,  limit * dt)
+    else:
+        step = max(delta, -limit * dt)
+    return current + step
+
+
+def _limit_velocity(linear_x, angular_z, max_linear, max_angular):
+    return (max(-max_linear,  min(max_linear,  linear_x)),
+            max(-max_angular, min(max_angular, angular_z)))
+
+
+def _check_emergency_stop(target_vel, target_vel_prev, dt,
+                           stop_threshold, hard_decel_threshold):
+    if target_vel < stop_threshold:
+        return True
+    if dt > 0 and (target_vel_prev - target_vel) / dt > hard_decel_threshold:
+        return True
+    return False
+
+
+def _check_gps_runaway(gps_speed, cmd_vel, runaway_factor, profile_max):
+    reference = max(abs(cmd_vel), 0.5)
+    return gps_speed > reference * runaway_factor and gps_speed > profile_max * 0.5
+
+
+def _emergency_decel_step(current_vel, decel_limit, dt):
+    if current_vel > 0:
+        return max(0.0, current_vel - decel_limit * dt)
+    if current_vel < 0:
+        return min(0.0, current_vel + decel_limit * dt)
+    return 0.0
+
+
+# ── Target velocity estimation ────────────────────────────────────────────────
+
+class TestTargetVelocityEstimation:
+    def test_target_faster_than_robot(self):
+        # Robot at 2 m/s GPS, range increasing 3 m/s → target at 5 m/s
+        v = _estimate_target_velocity(5.0, 8.0, 1.0, 2.0)   # range: 5→8 in 1s
+        assert v == pytest.approx(5.0)
+
+    def test_target_same_speed_constant_range(self):
+        v = _estimate_target_velocity(5.0, 5.0, 1.0, 3.0)
+        assert v == pytest.approx(3.0)
+
+    def test_target_stopped_range_closing(self):
+        # Robot at 3 m/s, range closing 3 m/s → target = 3 - 3 = 0 → clamped to 0
+        v = _estimate_target_velocity(8.0, 5.0, 1.0, 3.0)
+        assert v == pytest.approx(0.0)
+
+    def test_invalid_dt_returns_gps_speed(self):
+        assert _estimate_target_velocity(5.0, 6.0, 0.0, 2.5) == pytest.approx(2.5)
+
+    def test_invalid_prev_range_returns_gps_speed(self):
+        assert _estimate_target_velocity(0.0, 6.0, 1.0, 2.5) == pytest.approx(2.5)
+
+    def test_result_non_negative(self):
+        # Range closing much faster than robot → would be negative → clamp to 0
+        v = _estimate_target_velocity(10.0, 3.0, 0.5, 1.0)
+        assert v >= 0.0
+
+    def test_high_speed_ride_estimate(self):
+        # Robot at 6 m/s, range increasing 2 m/s → target at 8 m/s
+        v = _estimate_target_velocity(4.0, 5.0, 0.5, 6.0)   # 2 m/s range rate
+        assert v == pytest.approx(8.0)
+
+
+# ── Profile selection ─────────────────────────────────────────────────────────
+
+class TestProfileSelection:
+    def test_walk_range_stays_walk(self):
+        assert _select_profile(1.0, _PROFILES, WALK) == WALK
+
+    def test_jog_range_stays_jog(self):
+        assert _select_profile(3.5, _PROFILES, JOG) == JOG
+
+    def test_ride_range_stays_ride(self):
+        assert _select_profile(7.0, _PROFILES, RIDE) == RIDE
+
+    def test_upgrade_needs_hysteresis_up(self):
+        # Should NOT upgrade immediately
+        counters = {}
+        profile = WALK
+        # 4 ticks at jog speed — not enough (hysteresis_up=5)
+        for _ in range(4):
+            profile = _select_profile(3.0, _PROFILES, profile,
+                                      hysteresis_up=5, counters=counters)
+        assert profile == WALK
+
+    def test_upgrade_happens_at_threshold(self):
+        counters = {}
+        profile = WALK
+        for _ in range(5):
+            profile = _select_profile(3.0, _PROFILES, profile,
+                                      hysteresis_up=5, counters=counters)
+        assert profile == JOG
+
+    def test_downgrade_needs_more_hysteresis(self):
+        counters = {}
+        profile = JOG
+        for _ in range(9):
+            profile = _select_profile(1.0, _PROFILES, profile,
+                                      hysteresis_down=10, counters=counters)
+        assert profile == JOG   # not yet
+
+    def test_downgrade_happens_at_threshold(self):
+        counters = {}
+        profile = JOG
+        for _ in range(10):
+            profile = _select_profile(1.0, _PROFILES, profile,
+                                      hysteresis_down=10, counters=counters)
+        assert profile == WALK
+
+    def test_counters_cleared_on_stable(self):
+        counters = {}
+        # Partial upgrade attempt then target returns to walk range
+        _select_profile(3.0, _PROFILES, WALK, hysteresis_up=5, counters=counters)
+        _select_profile(3.0, _PROFILES, WALK, hysteresis_up=5, counters=counters)
+        assert JOG in counters   # counter accumulated
+        _select_profile(1.0, _PROFILES, WALK, hysteresis_up=5, counters=counters)
+        assert len(counters) == 0   # cleared when stable
+
+    def test_above_all_profiles_selects_ride(self):
+        profile = _select_profile(20.0, _PROFILES, RIDE)
+        assert profile == RIDE
+
+    def test_boundary_walk_max(self):
+        # 2.0 m/s is exactly at walk max → stays walk
+        assert _select_profile(2.0, _PROFILES, WALK) == WALK
+
+    def test_just_above_walk_max_triggers_upgrade(self):
+        counters = {}
+        profile = WALK
+        for _ in range(5):
+            profile = _select_profile(2.01, _PROFILES, profile,
+                                      hysteresis_up=5, counters=counters)
+        assert profile == JOG
+
+
+# ── Acceleration limiter ──────────────────────────────────────────────────────
+
+class TestAccelLimit:
+    _DT = 0.02   # 50 Hz
+
+    def test_accel_step(self):
+        # 0 → 1 at 0.5 m/s², 0.02s tick → step = 0.01
+        v = _apply_accel_limit(0.0, 1.0, 0.5, 1.0, self._DT)
+        assert v == pytest.approx(0.01)
+
+    def test_decel_step(self):
+        # 1 → 0 at 1.0 m/s², 0.02s → step = 0.02
+        v = _apply_accel_limit(1.0, 0.0, 0.5, 1.0, self._DT)
+        assert v == pytest.approx(0.98)
+
+    def test_does_not_overshoot(self):
+        # Close to target (gap < step)
+        v = _apply_accel_limit(0.995, 1.0, 0.5, 1.0, self._DT)
+        assert v == pytest.approx(1.0)
+
+    def test_does_not_undershoot(self):
+        v = _apply_accel_limit(0.005, 0.0, 0.5, 1.0, self._DT)
+        assert v == pytest.approx(0.0)
+
+    def test_negative_to_positive(self):
+        # -1 → 0 (decelerating negative) at decel_limit
+        v = _apply_accel_limit(-1.0, 0.0, 0.5, 1.0, self._DT)
+        assert v == pytest.approx(-0.98)   # reduced magnitude
+
+    def test_zero_to_zero(self):
+        assert _apply_accel_limit(0.0, 0.0, 0.5, 1.0, self._DT) == pytest.approx(0.0)
+
+    def test_ride_accel_gentler_than_walk(self):
+        dt = 0.02
+        v_walk = _apply_accel_limit(0.0, 5.0,
+                                     _PROFILES[WALK]["accel_limit"],
+                                     _PROFILES[WALK]["decel_limit"], dt)
+        v_ride = _apply_accel_limit(0.0, 5.0,
+                                     _PROFILES[RIDE]["accel_limit"],
+                                     _PROFILES[RIDE]["decel_limit"], dt)
+        assert v_walk > v_ride   # walk accelerates faster than ride
+
+    def test_time_to_reach_walk_max(self):
+        # walk: accel=0.6 m/s², target=1.5 m/s, dt=0.02s
+        # expected ticks ≈ 1.5 / (0.6 * 0.02) = 125 ticks
+        v = 0.0
+        ticks = 0
+        for _ in range(200):
+            v = _apply_accel_limit(v, 1.5, 0.6, 1.0, 0.02)
+            ticks += 1
+            if v >= 1.5 - 1e-6:
+                break
+        assert v == pytest.approx(1.5, abs=1e-4)
+        assert 120 <= ticks <= 130   # ≈ 125 ticks
+
+
+# ── Velocity limiter ──────────────────────────────────────────────────────────
+
+class TestLimitVelocity:
+    def test_within_limits(self):
+        lin, ang = _limit_velocity(1.0, 0.5, 8.0, 1.5)
+        assert lin == pytest.approx(1.0)
+        assert ang == pytest.approx(0.5)
+
+    def test_linear_clamped_high(self):
+        lin, _ = _limit_velocity(10.0, 0.0, 8.0, 1.5)
+        assert lin == pytest.approx(8.0)
+
+    def test_linear_clamped_low(self):
+        lin, _ = _limit_velocity(-10.0, 0.0, 8.0, 1.5)
+        assert lin == pytest.approx(-8.0)
+
+    def test_angular_clamped(self):
+        _, ang = _limit_velocity(0.0, 5.0, 8.0, 1.5)
+        assert ang == pytest.approx(1.5)
+
+    def test_zero_passthrough(self):
+        lin, ang = _limit_velocity(0.0, 0.0, 8.0, 1.5)
+        assert lin == pytest.approx(0.0)
+        assert ang == pytest.approx(0.0)
+
+
+# ── Emergency stop detection ──────────────────────────────────────────────────
+
+class TestEmergencyStop:
+    def test_triggers_below_stop_threshold(self):
+        assert _check_emergency_stop(0.2, 3.0, 0.02, 0.4, 3.0) is True
+
+    def test_triggers_on_hard_decel(self):
+        # target_vel drops from 5 to 3 in 0.02s → decel = 100 m/s² >> 3.0
+        assert _check_emergency_stop(3.0, 5.0, 0.02, 0.4, 3.0) is True
+
+    def test_no_trigger_gradual_decel(self):
+        # 5 → 4 in 0.02s → decel = 50 m/s² >> threshold... wait, 50 > 3
+        # Let me use a smaller decel: 5 → 4.9 in 0.02s → decel = 5 m/s²... still > 3
+        # Use 5 → 4.9 in 0.1s → decel = 1.0 m/s²
+        assert _check_emergency_stop(4.9, 5.0, 0.1, 0.4, 3.0) is False
+
+    def test_no_trigger_at_cruising_speed(self):
+        assert _check_emergency_stop(6.0, 6.0, 0.02, 0.4, 3.0) is False
+
+    def test_boundary_exactly_at_stop_threshold(self):
+        # target_vel == stop_threshold → NOT < → no trigger
+        # prev must be close enough that decel check doesn't also fire:
+        # (0.42 - 0.40) / 0.02 = 1.0 m/s² < 3.0 → OK
+        assert _check_emergency_stop(0.4, 0.42, 0.02, 0.4, 3.0) is False
+
+    def test_triggers_just_below_threshold(self):
+        assert _check_emergency_stop(0.39, 1.0, 0.02, 0.4, 3.0) is True
+
+
+# ── GPS runaway detection ─────────────────────────────────────────────────────
+
+class TestGpsRunaway:
+    def test_runaway_detected(self):
+        # GPS 5 m/s, commanded 2 m/s → 5 > 2*1.5=3, 5 > 8*0.5=4 → True
+        assert _check_gps_runaway(5.0, 2.0, 1.5, 8.0) is True
+
+    def test_no_runaway_normal(self):
+        # GPS 2.1 m/s, commanded 2 m/s → 2.1 not > 3.0
+        assert _check_gps_runaway(2.1, 2.0, 1.5, 8.0) is False
+
+    def test_no_runaway_stationary(self):
+        # Robot stopped (GPS 0.1 m/s, cmd 0), reference = max(0,0.5) = 0.5
+        # 0.1 not > 0.5*1.5=0.75
+        assert _check_gps_runaway(0.1, 0.0, 1.5, 1.5) is False
+
+    def test_runaway_only_at_meaningful_speed(self):
+        # GPS=6, cmd=4, factor=1.5 → 6 > 4*1.5=6 → False (not strictly greater)
+        assert _check_gps_runaway(6.0, 4.0, 1.5, 8.0) is False
+
+    def test_runaway_needs_gps_above_half_profile_max(self):
+        # Even if ratio is high, below 50% of profile max → no trigger
+        # profile_max=8 → threshold=4; GPS=3 < 4 → no trigger
+        assert _check_gps_runaway(3.0, 0.5, 1.5, 8.0) is False
+
+
+# ── Emergency decel step ──────────────────────────────────────────────────────
+
+class TestEmergencyDecelStep:
+    _DT = 0.02
+    _DECEL = 2.0
+
+    def test_positive_speed_decreases(self):
+        v = _emergency_decel_step(5.0, self._DECEL, self._DT)
+        assert v == pytest.approx(5.0 - 2.0 * 0.02)
+
+    def test_negative_speed_increases(self):
+        v = _emergency_decel_step(-5.0, self._DECEL, self._DT)
+        assert v == pytest.approx(-5.0 + 2.0 * 0.02)
+
+    def test_does_not_go_past_zero_positive(self):
+        v = _emergency_decel_step(0.03, self._DECEL, self._DT)
+        assert v == pytest.approx(0.0)   # 0.03 - 0.04 → clamped to 0
+
+    def test_does_not_go_past_zero_negative(self):
+        v = _emergency_decel_step(-0.03, self._DECEL, self._DT)
+        assert v == pytest.approx(0.0)
+
+    def test_zero_stays_zero(self):
+        assert _emergency_decel_step(0.0, self._DECEL, self._DT) == 0.0
+
+    def test_full_stop_from_ride_speed(self):
+        # 8 m/s at 2.0 m/s² → ticks to stop = 8 / (2.0 * 0.02) = 200 ticks = 4s
+        v = 8.0
+        ticks = 0
+        for _ in range(500):
+            v = _emergency_decel_step(v, 2.0, 0.02)
+            ticks += 1
+            if v == 0.0:
+                break
+        assert v == 0.0
+        assert 195 <= ticks <= 205
+
+
+# ── Integration: profile + accel + limit ─────────────────────────────────────
+
+class TestIntegration:
+    """End-to-end control step simulation."""
+
+    def _step(self, current, request, profile_name, dt=0.02):
+        p = _PROFILES[profile_name]
+        capped_lin, capped_ang = _limit_velocity(
+            request, 0.0, p["max_linear_vel"], p["max_angular_vel"])
+        new_lin = _apply_accel_limit(
+            current, capped_lin, p["accel_limit"], p["decel_limit"], dt)
+        return new_lin
+
+    def test_walk_stays_under_1p5(self):
+        v = 0.0
+        for _ in range(300):
+            v = self._step(v, 5.0, WALK)   # request far above limit
+        assert v <= 1.5 + 1e-6
+
+    def test_ride_reaches_8_from_zero(self):
+        v = 0.0
+        for _ in range(5000):
+            v = self._step(v, 8.0, RIDE)
+        assert v == pytest.approx(8.0, abs=1e-4)
+
+    def test_emergency_overrides_profile(self):
+        v = 6.0   # at ride speed
+        # Emergency: decel toward 0
+        for _ in range(500):
+            v = _emergency_decel_step(v, 2.0, 0.02)
+            if v == 0.0:
+                break
+        assert v == pytest.approx(0.0)
+
+    def test_profile_upgrade_then_downgrade_cycle(self):
+        counters = {}
+        profile = WALK
+        # Upgrade: 5 ticks at jog speed
+        for _ in range(5):
+            profile = _select_profile(3.0, _PROFILES, profile,
+                                      hysteresis_up=5, counters=counters)
+        assert profile == JOG
+        # Downgrade: 10 ticks at walk speed
+        counters = {}
+        for _ in range(10):
+            profile = _select_profile(1.0, _PROFILES, profile,
+                                      hysteresis_down=10, counters=counters)
+        assert profile == WALK

lib/USB_CDC/include/usbd_cdc_if.h

@@ -14,4 +14,7 @@ void checkForBootloader(void);
 /* PID tuning command interface (written by USB IRQ, read by main loop) */
 extern volatile uint8_t cdc_cmd_ready;
 extern volatile char    cdc_cmd_buf[32];
+
+extern volatile uint8_t cdc_estop_request;
+extern volatile uint8_t cdc_estop_clear_request;
 #endif

lib/USB_CDC/src/usbd_cdc_if.c

@@ -9,6 +9,9 @@ volatile uint8_t  cdc_disarm_request = 0; /* set by D command */
 volatile uint8_t  cdc_recal_request = 0;  /* set by G command — gyro recalibration */
 volatile uint32_t cdc_rx_count = 0;       /* total CDC packets received from host */
 
+volatile uint8_t  cdc_estop_request = 0;
+volatile uint8_t  cdc_estop_clear_request = 0;
+
 /*
  * PID tuning command buffer.
  * CDC_Receive (USB IRQ) copies multi-char commands here.
@@ -143,6 +146,10 @@ static int8_t CDC_Receive(uint8_t *buf, uint32_t *len) {
         case 'G': cdc_recal_request = 1;          break; /* gyro recalibration */
         case 'R': request_bootloader();            break; /* never returns */
 
+        case 'E': cdc_estop_request = 1;       break;
+        case 'F': cdc_estop_request = 2;       break;
+        case 'Z': cdc_estop_clear_request = 1; break;
+
         /*
          * PID tuning: P<kp>  I<ki>  D<kd>  T<setpoint>  M<max_speed>  ?
          * Copy to cmd buffer; main loop parses float (avoids sscanf in IRQ).

projects/saltybot/SLAM-SETUP-PLAN.md

@@ -92,7 +92,8 @@ Jetson Orin Nano Super (Ubuntu 22.04 / JetPack 6 / CUDA 12.x)
 | 2a | ✅ Done (PR #17) | Sensor drivers — `saltybot_bringup` package |
 | 2a+ | ✅ Done (PR #36) | Orin update: Dockerfile JetPack 6, RTAB-Map launch + config |
 | 2b | ✅ Done (PR #49) | Nav2 integration — path planning + obstacle avoidance |
-| 2c | ✅ Done (this PR) | 4× IMX219 surround vision + Nav2 camera obstacle layer |
+| 2c | ✅ Done (PR #52) | 4× IMX219 surround vision + Nav2 camera obstacle layer |
+| 2d | ✅ Done (this PR) | Outdoor navigation — OSM routing + GPS waypoints + geofence |
 
 ---
 

src/main.c

@@ -25,6 +25,8 @@ extern volatile uint8_t  cdc_arm_request;    /* set by A command */
 extern volatile uint8_t  cdc_disarm_request; /* set by D command */
 extern volatile uint8_t  cdc_recal_request;  /* set by G command */
 extern volatile uint32_t cdc_rx_count;       /* total CDC packets received */
+extern volatile uint8_t  cdc_estop_request;
+extern volatile uint8_t  cdc_estop_clear_request;
 
 /*
  * Apply a PID tuning command string from the USB terminal.
@@ -178,6 +180,20 @@ int main(void) {
         /* Mode manager: update RC liveness, CH6 mode selection, blend ramp */
         mode_manager_update(&mode, now);
 
+        if (cdc_estop_request) {
+            EstopSource src = (cdc_estop_request == 1) ? ESTOP_REMOTE : ESTOP_CELLULAR_TIMEOUT;
+            cdc_estop_request = 0;
+            safety_remote_estop(src);
+            safety_arm_cancel();
+            balance_disarm(&bal);
+            motor_driver_estop(&motors);
+        }
+        if (cdc_estop_clear_request) {
+            cdc_estop_clear_request = 0;
+            if (safety_remote_estop_active() && bal.state == BALANCE_DISARMED)
+                safety_remote_estop_clear();
+        }
+
         /* RC CH5 kill switch: disarm immediately if RC is alive and CH5 off.
          * Applies regardless of active mode (CH5 always has kill authority). */
         if (mode.rc_alive && !crsf_state.armed && bal.state == BALANCE_ARMED) {
@@ -202,7 +218,8 @@ int main(void) {
             bool rc_armed_now = safety_rc_alive(now) && crsf_state.armed;
             if (rc_armed_now && !s_rc_armed_prev) {
                 /* Rising edge: start arm hold (motors enable after ARMING_HOLD_MS) */
-                if (mpu6000_is_calibrated() &&
+                if (!safety_remote_estop_active() &&
+                        mpu6000_is_calibrated() &&
                         bal.state == BALANCE_DISARMED && fabsf(bal.pitch_deg) < 10.0f) {
                     safety_arm_start(now);
                 }
@@ -218,8 +235,8 @@ int main(void) {
         /* Handle arm/disarm requests from USB with arm-hold interlock */
         if (cdc_arm_request) {
             cdc_arm_request = 0;
-            /* Block arming until gyro calibration is complete */
-            if (mpu6000_is_calibrated() &&
+            if (!safety_remote_estop_active() &&
+                    mpu6000_is_calibrated() &&
                     bal.state == BALANCE_DISARMED && fabsf(bal.pitch_deg) < 10.0f) {
                 safety_arm_start(now);
             }
@@ -269,7 +286,8 @@ int main(void) {
         /* Latch estop on tilt fault or disarm */
         if (bal.state == BALANCE_TILT_FAULT) {
             motor_driver_estop(&motors);
-        } else if (bal.state == BALANCE_DISARMED && motors.estop) {
+        } else if (bal.state == BALANCE_DISARMED && motors.estop &&
+                   !safety_remote_estop_active()) {
             motor_driver_estop_clear(&motors);
         }
 
@@ -353,10 +371,14 @@ int main(void) {
                     p += n; rem -= n;
                 }
                 /* Jetson active flag, USB TX/RX packet counters */
-                n = snprintf(p, rem, ",\"ja\":%d,\"txc\":%u,\"rxc\":%u}\n",
+                int es; EstopSource _rs = safety_get_estop();
+                if (_rs >= ESTOP_REMOTE) es = (int)_rs;
+                else if (bal.state == BALANCE_TILT_FAULT) es = ESTOP_TILT;
+                else es = ESTOP_CLEAR;
+                n = snprintf(p, rem, ",\"ja\":%d,\"txc\":%u,\"rxc\":%u,\"es\":%d}\n",
                     jetson_cmd_is_active(now) ? 1 : 0,
                     (unsigned)tx_count,
-                    (unsigned)cdc_rx_count);
+                    (unsigned)cdc_rx_count, es);
                 len = (int)(p + n - buf);
             } else {
                 len = snprintf(buf, sizeof(buf), "{\"err\":%d}\n", imu_ret);
@@ -367,7 +389,8 @@ int main(void) {
 
         status_update(now, (imu_ret == 0),
                       (bal.state == BALANCE_ARMED),
-                      (bal.state == BALANCE_TILT_FAULT));
+                      (bal.state == BALANCE_TILT_FAULT),
+                      safety_remote_estop_active());
         HAL_Delay(1);
     }
 }

src/safety.c

@@ -33,6 +33,8 @@ static bool     s_arm_pending  = false;
 /* Tilt fault alert state — edge-detect to fire buzzer once */
 static bool s_was_faulted = false;
 
+static EstopSource s_estop_source = ESTOP_CLEAR;
+
 void safety_init(void) {
     hiwdg.Instance       = IWDG;
     hiwdg.Init.Prescaler = IWDG_PRESCALER;
@@ -76,3 +78,8 @@ bool safety_arm_ready(uint32_t now) {
 void safety_arm_cancel(void) {
     s_arm_pending = false;
 }
+
+void safety_remote_estop(EstopSource src) { s_estop_source = src; }
+void safety_remote_estop_clear(void) { s_estop_source = ESTOP_CLEAR; }
+EstopSource safety_get_estop(void) { return s_estop_source; }
+bool safety_remote_estop_active(void) { return s_estop_source >= ESTOP_REMOTE; }

src/status.c

@@ -42,11 +42,14 @@ void status_boot_beep(void) {
     HAL_GPIO_WritePin(BEEPER_PORT, BEEPER_PIN, GPIO_PIN_RESET);
 }
 
-void status_update(uint32_t tick, int imu_ok, int armed, int tilt_fault) {
-    /* Solid = good, blink = needs attention (1 Hz, 500ms half-period) */
+void status_update(uint32_t tick, int imu_ok, int armed, int tilt_fault, int remote_estop) {
+    GPIO_PinState fast_blink = ((tick / 200) % 2) ? GPIO_PIN_RESET : GPIO_PIN_SET;
     GPIO_PinState blink = ((tick / 500) % 2) ? GPIO_PIN_RESET  /* ON half */
                                               : GPIO_PIN_SET;   /* OFF half */
-    if (!imu_ok) {
+    if (remote_estop) {
+        HAL_GPIO_WritePin(LED1_PORT, LED1_PIN, fast_blink);
+        HAL_GPIO_WritePin(LED2_PORT, LED2_PIN, fast_blink);
+    } else if (!imu_ok) {
         /* IMU error: LED1 blinking (attention), LED2 solid ON */
         HAL_GPIO_WritePin(LED1_PORT, LED1_PIN, blink);
         HAL_GPIO_WritePin(LED2_PORT, LED2_PIN, GPIO_PIN_RESET);