feat: VESC SocketCAN dual-motor driver IDs 61/79 (Issue #644)

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

jetson/ros2_ws/src/saltybot_bringup/systemd/can-bringup.service

@@ -0,0 +1,21 @@
+[Unit]
+Description=CANable 2.0 CAN bus bringup (can0, 500 kbps)
+Documentation=https://gitea.vayrette.com/seb/saltylab-firmware/issues/643
+# Wait until the gs_usb net device appears; udev fires After=sys-subsystem-net-devices-can0.device
+After=network.target sys-subsystem-net-devices-can0.device
+Requires=sys-subsystem-net-devices-can0.device
+BindsTo=sys-subsystem-net-devices-can0.device
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+
+ExecStart=/usr/sbin/ip link set can0 up type can bitrate 500000
+ExecStop=/usr/sbin/ip link set can0 down
+
+StandardOutput=journal
+StandardError=journal
+SyslogIdentifier=can-bringup
+
+[Install]
+WantedBy=multi-user.target

jetson/ros2_ws/src/saltybot_bringup/udev/70-canable.rules

@@ -0,0 +1,19 @@
+# CANable 2.0 USB-CAN adapter (gs_usb driver)
+# Exposes the adapter as can0 via the SocketCAN subsystem.
+# Issue: https://gitea.vayrette.com/seb/saltylab-firmware/issues/643
+#
+# Install:
+#   sudo cp 70-canable.rules /etc/udev/rules.d/
+#   sudo udevadm control --reload && sudo udevadm trigger
+#
+# CANable 2.0 USB IDs (Geschwister Schneider / candleLight firmware):
+#   idVendor  = 1d50  (OpenMoko)
+#   idProduct = 606f  (candleLight / gs_usb)
+#
+# Verify with: lsusb | grep -i candl
+#              ip link show can0
+
+SUBSYSTEM=="net", ACTION=="add", \
+    ATTRS{idVendor}=="1d50", ATTRS{idProduct}=="606f", \
+    NAME="can0", \
+    RUN+="/sbin/ip link set can0 up type can bitrate 500000"

jetson/ros2_ws/src/saltybot_vesc_driver/config/vesc_params.yaml

@@ -1,20 +1,10 @@
-# VESC Driver Configuration for SaltyBot
+vesc_can_driver:
-# Flipsky FSESC 4.20 Plus (VESC dual ESC) motor control
-
-vesc_driver:
   ros__parameters:
-    # Serial communication
+    interface: can0
-    port: "/dev/ttyUSB0"
+    bitrate: 500000
-    baudrate: 115200
+    left_motor_id: 61
-
+    right_motor_id: 79
-    # Command mode: "duty_cycle" or "rpm"
+    wheel_separation: 0.5
-    # duty_cycle: Direct motor duty cycle (-100 to 100)
+    wheel_radius: 0.1
-    # rpm: RPM setpoint mode (closed-loop speed control)
+    max_speed: 5.0
-    command_mode: "duty_cycle"
+    command_timeout: 1.0
-
-    # Motor limits
-    max_rpm: 60000
-    max_current_a: 50.0
-
-    # Command timeout: If no cmd_vel received for this duration, motor stops
-    timeout_s: 1.0

jetson/ros2_ws/src/saltybot_vesc_driver/launch/vesc_driver.launch.py

@@ -1,4 +1,4 @@
-"""Launch file for VESC driver node."""
+"""Launch file for VESC CAN driver node."""
 
 from launch import LaunchDescription
 from launch_ros.actions import Node
@@ -9,7 +9,7 @@ from ament_index_python.packages import get_package_share_directory
 
 
 def generate_launch_description():
-    """Generate launch description for VESC driver."""
+    """Generate launch description for VESC CAN driver."""
     pkg_dir = get_package_share_directory("saltybot_vesc_driver")
     config_file = os.path.join(pkg_dir, "config", "vesc_params.yaml")
 
@@ -20,15 +20,10 @@ def generate_launch_description():
                 default_value=config_file,
                 description="Path to configuration YAML file",
             ),
-            DeclareLaunchArgument(
-                "port",
-                default_value="/dev/ttyUSB0",
-                description="Serial port for VESC",
-            ),
             Node(
                 package="saltybot_vesc_driver",
                 executable="vesc_driver_node",
-                name="vesc_driver",
+                name="vesc_can_driver",
                 output="screen",
                 parameters=[LaunchConfiguration("config_file")],
             ),

jetson/ros2_ws/src/saltybot_vesc_driver/package.xml

@@ -14,6 +14,8 @@
   <depend>geometry_msgs</depend>
   <depend>std_msgs</depend>
 
+  <exec_depend>python3-can</exec_depend>
+
   <buildtool_depend>ament_python</buildtool_depend>
 
   <test_depend>ament_copyright</test_depend>

jetson/ros2_ws/src/saltybot_vesc_driver/saltybot_vesc_driver/vesc_driver_node.py

@@ -1,222 +1,133 @@
 #!/usr/bin/env python3
-"""VESC UART driver node for SaltyBot.
+"""
+VESC CAN driver node using python-can with SocketCAN.
+Subscribes to /cmd_vel (geometry_msgs/Twist) and sends duty cycle
+commands to two VESC motor controllers via CAN bus.
 
-Uses pyvesc library to communicate with Flipsky FSESC 4.20 Plus (VESC dual ESC).
+VESC CAN protocol:
-Subscribes to velocity commands and publishes motor telemetry.
+  Extended frame ID = (CAN_PACKET_ID << 8) | VESC_ID
-
+  CAN_PACKET_SET_DUTY = 0  -> payload: int32 (duty * 100000)
-Subscribed topics:
-  /cmd_vel (geometry_msgs/Twist) - Velocity command (linear.x = m/s, angular.z = rad/s)
-
-Published topics:
-  /vesc/state (VESCState) - Motor telemetry (voltage, current, RPM, temperature, fault)
-  /vesc/raw_telemetry (String) - Raw telemetry JSON for debugging
 """
 
-import json
+import struct
-import threading
 import time
-from enum import Enum
-from typing import Optional
 
+import can
 import rclpy
-from rclpy.node import Node
 from geometry_msgs.msg import Twist
-from std_msgs.msg import String
+from rclpy.node import Node
-import serial
-
-try:
-    import pyvesc
-except ImportError:
-    pyvesc = None
 
 
-class VESCCommandMode(Enum):
+# VESC CAN packet IDs
-    """VESC command modes."""
+CAN_PACKET_SET_DUTY = 0
-    DUTY_CYCLE = "duty_cycle"  # Direct duty cycle (-100 to 100)
+CAN_PACKET_SET_RPM = 3
-    RPM = "rpm"               # RPM setpoint
-    CURRENT = "current"       # Current (A)
-    BRAKE_CURRENT = "brake"   # Brake current (A)
 
 
-class VESCState:
+def make_can_id(packet_id: int, vesc_id: int) -> int:
-    """VESC telemetry state."""
+    """Build extended CAN frame ID for VESC."""
+    return (packet_id << 8) | vesc_id
 
+
+class VescCanDriver(Node):
     def __init__(self):
-        self.voltage_v = 0.0
+        super().__init__('vesc_can_driver')
-        self.current_a = 0.0
-        self.rpm = 0
-        self.temperature_c = 0.0
-        self.fault_code = 0
-        self.timestamp = time.time()
 
+        # Declare parameters
+        self.declare_parameter('interface', 'can0')
+        self.declare_parameter('left_motor_id', 61)
+        self.declare_parameter('right_motor_id', 79)
+        self.declare_parameter('wheel_separation', 0.5)
+        self.declare_parameter('wheel_radius', 0.1)
+        self.declare_parameter('max_speed', 5.0)
+        self.declare_parameter('command_timeout', 1.0)
 
-class VESCDriverNode(Node):
+        # Read parameters
-    """ROS2 node for VESC motor control and telemetry."""
+        self.interface = self.get_parameter('interface').value
+        self.left_id = self.get_parameter('left_motor_id').value
+        self.right_id = self.get_parameter('right_motor_id').value
+        self.wheel_sep = self.get_parameter('wheel_separation').value
+        self.max_speed = self.get_parameter('max_speed').value
+        self.cmd_timeout = self.get_parameter('command_timeout').value
 
-    def __init__(self):
+        # Open CAN bus
-        super().__init__("vesc_driver")
+        try:
+            self.bus = can.interface.Bus(
+                channel=self.interface,
+                bustype='socketcan',
+            )
+            self.get_logger().info(f'CAN bus opened: {self.interface}')
+        except Exception as e:
+            self.get_logger().error(f'Failed to open CAN bus: {e}')
+            raise
 
-        # Parameters
+        self._last_cmd_time = time.monotonic()
-        self.declare_parameter("port", "/dev/ttyUSB0")
-        self.declare_parameter("baudrate", 115200)
-        self.declare_parameter("command_mode", "duty_cycle")  # or "rpm"
-        self.declare_parameter("max_rpm", 60000)
-        self.declare_parameter("max_current_a", 50.0)
-        self.declare_parameter("timeout_s", 1.0)
 
-        self.port = self.get_parameter("port").value
+        # Subscriber
-        self.baudrate = self.get_parameter("baudrate").value
+        self.create_subscription(Twist, '/cmd_vel', self._cmd_vel_cb, 10)
-        self.command_mode = self.get_parameter("command_mode").value
-        self.max_rpm = self.get_parameter("max_rpm").value
-        self.max_current_a = self.get_parameter("max_current_a").value
-        self.timeout_s = self.get_parameter("timeout_s").value
 
-        # Serial connection
+        # Watchdog timer (10 Hz)
-        self.serial = None
+        self.create_timer(0.1, self._watchdog_cb)
-        self.vesc = None
-        self.last_cmd_time = 0
-        self.state = VESCState()
-
-        # Subscriptions
-        self.create_subscription(Twist, "/cmd_vel", self._on_cmd_vel, 10)
-
-        # Publishers
-        self.pub_state = self.create_publisher(String, "/vesc/state", 10)
-        self.pub_telemetry = self.create_publisher(String, "/vesc/raw_telemetry", 10)
-
-        # Timer for telemetry polling (100 Hz)
-        self.create_timer(0.01, self._poll_telemetry)
-
-        # Initialize VESC connection
-        self._init_vesc()
 
         self.get_logger().info(
-            f"VESC driver initialized: port={self.port}, baud={self.baudrate}, "
+            f'VESC CAN driver ready — left={self.left_id} right={self.right_id}'
-            f"mode={self.command_mode}, timeout={self.timeout_s}s"
         )
 
-    def _init_vesc(self) -> bool:
+    # ------------------------------------------------------------------
-        """Initialize serial connection to VESC."""
+
+    def _cmd_vel_cb(self, msg: Twist):
+        self._last_cmd_time = time.monotonic()
+        linear = msg.linear.x
+        angular = msg.angular.z
+
+        left_speed = linear - (angular * self.wheel_sep / 2.0)
+        right_speed = linear + (angular * self.wheel_sep / 2.0)
+
+        left_duty = max(-1.0, min(1.0, left_speed / self.max_speed))
+        right_duty = max(-1.0, min(1.0, right_speed / self.max_speed))
+
+        self._send_duty(self.left_id, left_duty)
+        self._send_duty(self.right_id, right_duty)
+
+    def _watchdog_cb(self):
+        elapsed = time.monotonic() - self._last_cmd_time
+        if elapsed > self.cmd_timeout:
+            self._send_duty(self.left_id, 0.0)
+            self._send_duty(self.right_id, 0.0)
+
+    # ------------------------------------------------------------------
+
+    def _send_duty(self, vesc_id: int, duty: float):
+        """Send CAN_PACKET_SET_DUTY to a VESC controller."""
+        can_id = make_can_id(CAN_PACKET_SET_DUTY, vesc_id)
+        payload = struct.pack('>i', int(duty * 100000))
+        msg = can.Message(
+            arbitration_id=can_id,
+            data=payload,
+            is_extended_id=True,
+        )
         try:
-            if pyvesc is None:
+            self.bus.send(msg)
-                self.get_logger().error("pyvesc not installed. Install with: pip install pyvesc")
+        except can.CanError as e:
-                return False
+            self.get_logger().error(f'CAN send error (id={vesc_id}): {e}')
 
-            self.serial = serial.Serial(
+    def destroy_node(self):
-                port=self.port,
+        self._send_duty(self.left_id, 0.0)
-                baudrate=self.baudrate,
+        self._send_duty(self.right_id, 0.0)
-                timeout=0.1,
+        self.bus.shutdown()
-            )
+        super().destroy_node()
-            self.vesc = pyvesc.VescUart(
-                serial_port=self.serial,
-                has_sensor=False,  # No wheel speed sensor
-                start_heartbeat=True,
-            )
-
-            self.get_logger().info(f"Connected to VESC on {self.port} @ {self.baudrate} baud")
-            return True
-
-        except (serial.SerialException, Exception) as e:
-            self.get_logger().error(f"Failed to initialize VESC: {e}")
-            return False
-
-    def _on_cmd_vel(self, msg: Twist) -> None:
-        """Handle velocity command from /cmd_vel."""
-        if self.vesc is None:
-            return
-
-        try:
-            # Extract linear velocity (m/s) and angular velocity (rad/s)
-            linear_v = msg.linear.x
-            angular_v = msg.angular.z
-
-            # Convert velocity to VESC command based on mode
-            if self.command_mode == "duty_cycle":
-                # Map velocity to duty cycle (-100 to 100)
-                # Assuming max velocity ~5 m/s maps to ~100% duty
-                duty = max(-100, min(100, (linear_v / 5.0) * 100))
-                self.vesc.set_duty(duty / 100.0)  # pyvesc expects 0-1 or -1-0
-
-            elif self.command_mode == "rpm":
-                # Map velocity to RPM
-                # Assuming max velocity 5 m/s → max_rpm
-                rpm = max(-self.max_rpm, min(self.max_rpm, (linear_v / 5.0) * self.max_rpm))
-                self.vesc.set_rpm(int(rpm))
-
-            # Angular velocity could control steering if dual motors are used differently
-            # For now, it's ignored (single dual-motor ESC)
-
-            self.last_cmd_time = time.time()
-
-        except Exception as e:
-            self.get_logger().error(f"Error sending command to VESC: {e}")
-
-    def _poll_telemetry(self) -> None:
-        """Poll VESC for telemetry and publish state."""
-        if self.vesc is None:
-            return
-
-        try:
-            # Read telemetry from VESC
-            if self.vesc.read_values():
-                # Update state from VESC data
-                self.state.voltage_v = self.vesc.data.v_in
-                self.state.current_a = self.vesc.data.current_in
-                self.state.rpm = self.vesc.data.rpm
-                self.state.temperature_c = self.vesc.data.temp_fet
-                self.state.fault_code = self.vesc.data.fault_code
-                self.state.timestamp = time.time()
-
-                # Check for timeout
-                if time.time() - self.last_cmd_time > self.timeout_s:
-                    # No recent command, send zero
-                    if self.command_mode == "duty_cycle":
-                        self.vesc.set_duty(0.0)
-                    else:
-                        self.vesc.set_rpm(0)
-
-                # Publish state
-                self._publish_state()
-            else:
-                self.get_logger().warn("Failed to read VESC telemetry")
-
-        except Exception as e:
-            self.get_logger().error(f"Error polling VESC: {e}")
-
-    def _publish_state(self) -> None:
-        """Publish VESC state as JSON."""
-        state_dict = {
-            "voltage_v": round(self.state.voltage_v, 2),
-            "current_a": round(self.state.current_a, 2),
-            "rpm": self.state.rpm,
-            "temperature_c": round(self.state.temperature_c, 1),
-            "fault_code": self.state.fault_code,
-            "timestamp": self.state.timestamp,
-        }
-
-        msg = String(data=json.dumps(state_dict))
-        self.pub_state.publish(msg)
-        self.pub_telemetry.publish(msg)
-
-        # Log fault codes
-        if self.state.fault_code != 0:
-            self.get_logger().warn(f"VESC fault code: {self.state.fault_code}")
 
 
 def main(args=None):
     rclpy.init(args=args)
-    node = VESCDriverNode()
+    node = VescCanDriver()
     try:
         rclpy.spin(node)
     except KeyboardInterrupt:
         pass
     finally:
-        if node.vesc and node.serial:
-            node.vesc.set_duty(0.0)  # Zero throttle on shutdown
-            node.serial.close()
         node.destroy_node()
         rclpy.shutdown()
 
 
-if __name__ == "__main__":
+if __name__ == '__main__':
     main()

jetson/scripts/can_setup.sh

@@ -0,0 +1,52 @@
+#!/usr/bin/env bash
+# can_setup.sh — Bring up CANable 2.0 (gs_usb) as can0 at 500 kbps
+# Issue: https://gitea.vayrette.com/seb/saltylab-firmware/issues/643
+#
+# Usage:
+#   sudo ./can_setup.sh          # bring up
+#   sudo ./can_setup.sh down     # bring down
+#   sudo ./can_setup.sh verify   # candump one-shot check (Ctrl-C to stop)
+#
+# VESCs on bus: CAN ID 61 (0x3D) and CAN ID 79 (0x4F), 500 kbps
+set -euo pipefail
+
+IFACE="${CAN_IFACE:-can0}"
+BITRATE="${CAN_BITRATE:-500000}"
+
+log() { echo "[can_setup] $*"; }
+die() { echo "[can_setup] ERROR: $*" >&2; exit 1; }
+
+cmd="${1:-up}"
+
+case "$cmd" in
+  up)
+    # Verify the interface exists (gs_usb module loaded by kernel on plug-in)
+    if ! ip link show "$IFACE" &>/dev/null; then
+        die "$IFACE not found — is CANable 2.0 plugged in and gs_usb loaded?"
+    fi
+
+    log "Bringing up $IFACE at ${BITRATE} bps..."
+    ip link set "$IFACE" down 2>/dev/null || true
+    ip link set "$IFACE" up type can bitrate "$BITRATE"
+    ip link set "$IFACE" up
+    log "$IFACE is up."
+    ip -details link show "$IFACE"
+    ;;
+
+  down)
+    log "Bringing down $IFACE..."
+    ip link set "$IFACE" down
+    log "$IFACE is down."
+    ;;
+
+  verify)
+    log "Listening on $IFACE — expecting frames from VESC IDs 0x3D (61) and 0x4F (79)"
+    log "Press Ctrl-C to stop."
+    exec candump "$IFACE"
+    ;;
+
+  *)
+    echo "Usage: $0 [up|down|verify]"
+    exit 1
+    ;;
+esac