Rename: product -> "Resound"; firmware roles -> hud/sink/broadcaster

Product name BikeAudio -> "Resound" (the device isn't bike-specific — works at
home, backyard, camping, parties, group rides). This is the A2DP advertise name
the phone connects to: sink.start("Resound"). All banners/comments + README
updated. (After reflashing the sink, the phone must forget "BikeAudio" and
connect to "Resound".)

Firmware vocabulary clarified (the old hub/sink/source was confusing —
"source" read backwards since those boards SEND audio):
  hub_s3.cpp / env hub_s3        -> hud.cpp / env hud
  board_sink.cpp                 -> sink.cpp        (env sink)
  board_source.cpp               -> broadcaster.cpp (envs broadcaster_headset
                                    0x11, broadcaster_speaker1 0x10,
                                    broadcaster_guest 0x12)
  hub_proto.h                    -> bus_proto.h
default_envs = sink + the three broadcasters. All envs build clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README_RELAY.md

@@ -1,4 +1,4 @@
-# BikeAudio — 3-board Bluetooth relay
+# Resound — 3-board Bluetooth relay
 
 Relays iPhone audio to **two** Bluetooth speakers (JBL Charge 5 + Cardo "Tangerine EDGE")
 at the same time.
@@ -89,7 +89,7 @@ B and C start reading it.
 1. Put the **JBL** and **Cardo** in pairing mode.
 2. Power Board B and Board C — each connects to its speaker by name
    (auto-reconnects on later power-ups).
-3. Power Board A; on the iPhone, connect to **"BikeAudio"**.
+3. Power Board A; on the iPhone, connect to **"Resound"**.
 4. Play audio — both speakers should output together.
 
 ## Known limitations

platformio.ini

@@ -1,17 +1,19 @@
-; BikeAudio — 3-board relay (iPhone -> Board A sink -> I2S -> Boards B/C sources -> JBL + Cardo)
+; BikeAudio — split-board Bluetooth audio relay.
 ;
-; One ESP32 cannot be an A2DP sink and source at once, and an A2DP source can
+; Roles (one ESP32 can't be A2DP sink+source, and a source reaches one speaker,
-; reach only one speaker — so the work is split across three boards that share
+; so the work is split across boards sharing an I2S audio bus + an I2C control bus):
-; an I2S bus. See README.md for wiring and the flash order.
+;   SINK        - iPhone connects here (A2DP in) -> drives the I2S bus as master
+;   BROADCASTER - reads I2S -> A2DP-streams to ONE speaker (one per channel)
+;   HUD         - ESP32-S3 round touch LCD; control panel over I2C
 ;
-; Build all:        pio run
+; Channels are brand-agnostic: Headset / Speaker 1 / Guest (discovery picks the
-; Build one board:  pio run -e sink | -e source_jbl | -e source_cardo
+; real device per channel). Build one: pio run -e sink | -e broadcaster_headset
+; | -e broadcaster_speaker1 | -e broadcaster_guest | -e hud
 ;
-; Common specs preserved from the original sketch: ESP32 Arduino core 2.0.x via
+; Audio boards: ESP32 core 2.0.x via espressif32 ~6.6.0, esp32dev, huge_app (BT stack).
-; espressif32 ~6.6.0, esp32dev, huge_app partition (BT stack), 115200 monitor.
 
 [platformio]
-default_envs = sink, source_jbl, source_cardo
+default_envs = sink, broadcaster_headset, broadcaster_speaker1, broadcaster_guest
 
 [env]
 platform = espressif32 @ ~6.6.0
@@ -24,47 +26,43 @@ lib_deps =
     https://github.com/pschatzmann/ESP32-A2DP#42601717cd70d5300c9b519f3c2bf1d64d77ea2b
     https://github.com/pschatzmann/arduino-audio-tools#64b64dcb9bde18a0a17766eeb6529c3a53d920a8
 
-; --- Board A: A2DP sink (iPhone) -> I2S master --------------------------------
+; --- SINK: A2DP sink (iPhone) -> I2S master ----------------------------------
 [env:sink]
-build_src_filter = +<board_sink.cpp>
+build_src_filter = +<sink.cpp>
 
-; --- Board B: I2S slave -> A2DP source -> JBL Charge 5 ------------------------
+; --- BROADCASTER "Headset" -> Cardo (I2C 0x11) -------------------------------
-[env:source_jbl]
+[env:broadcaster_headset]
-build_src_filter = +<board_source.cpp>
+build_src_filter = +<broadcaster.cpp>
-build_flags = '-DTARGET_SPEAKER="JBL Charge 5"' -DHUB_I2C_ADDR=0x10
-
-; --- Board C: I2S slave -> A2DP source -> Cardo (Tangerine EDGE) --------------
-[env:source_cardo]
-build_src_filter = +<board_source.cpp>
 build_flags = '-DTARGET_SPEAKER="Tangerine EDGE"' -DHUB_I2C_ADDR=0x11
 
-; --- Board D: I2S slave -> A2DP source -> GUEST speaker (antenna board) -------
+; --- BROADCASTER "Speaker 1" -> JBL (I2C 0x10) -------------------------------
-;     Occasional passenger speaker, furthest away (hence the onboard antenna).
+[env:broadcaster_speaker1]
-;     No hardcoded name — pick the speaker via the hub's scan UI (Phase 3).
+build_src_filter = +<broadcaster.cpp>
-[env:source_guest]
+build_flags = '-DTARGET_SPEAKER="JBL Charge 5"' -DHUB_I2C_ADDR=0x10
-build_src_filter = +<board_source.cpp>
+
+; --- BROADCASTER "Guest" -> antenna board, occasional passenger (I2C 0x12) ---
+;     No hardcoded device — pick the speaker via the HUD scan UI (discovery).
+[env:broadcaster_guest]
+build_src_filter = +<broadcaster.cpp>
 build_flags = '-DTARGET_SPEAKER="Guest"' -DHUB_I2C_ADDR=0x12
 
-; --- Hub: ESP32-S3-Touch-LCD-1.28 (round GC9A01 LCD + CST816S touch) ----------
+; --- HUD: ESP32-S3-Touch-LCD-1.28 (round GC9A01 LCD + CST816S touch) ----------
-;     Different chip (esp32s3) from the relay boards. Drives the UI; later the
+;     Different chip (esp32s3); LVGL UI + I2C master to the audio boards.
-;     wired control bus to Boards B/C. NOT in default_envs — build with -e hub_s3.
+;     NOT in default_envs — build with: pio run -e hud
-[env:hub_s3]
+[env:hud]
 platform = espressif32 @ ~6.6.0
 board = esp32-s3-devkitc-1
 framework = arduino
 board_upload.flash_size = 4MB
 board_build.partitions = default.csv
 monitor_speed = 115200
-build_src_filter = +<hub_s3.cpp>
+build_src_filter = +<hud.cpp>
 lib_deps =
     lovyan03/LovyanGFX@^1.1.16
     lvgl/lvgl@^8.3.11
-; LVGL configured via build flags (LV_CONF_SKIP -> defaults + overrides), so
+; LVGL via build flags (LV_CONF_SKIP -> defaults + overrides); no lv_conf.h.
-; there is no separate lv_conf.h to maintain. 16-bit colour, byte-swapped for
+; Keep flag values free of shell-special chars (parens/spaces). Tick via
-; the SPI panel; millis() tick; the big Montserrat fonts for glanceable text.
+; lv_tick_inc() in loop() (no LV_TICK_CUSTOM, which needs a parenthesised expr).
-; NOTE: keep flag values free of shell-special chars (parens/spaces) — they go
-; through a shell. LV_MEM_SIZE as a plain int; tick driven via lv_tick_inc() in
-; loop() (no LV_TICK_CUSTOM, which needs a parenthesised millis() expr).
 build_flags =
     -DLV_CONF_SKIP=1
     -DLV_COLOR_DEPTH=16

src/broadcaster.cpp

@@ -1,5 +1,5 @@
 /**
- * BikeAudio — Boards B & C : I2S SLAVE -> [FIFO delay] -> A2DP SOURCE
+ * Resound — Boards B & C : I2S SLAVE -> [FIFO delay] -> A2DP SOURCE
  *
  * Reads PCM from the shared I2S bus (clocked by Board A) into a FIFO, and an
  * A2DP source drains the FIFO to one Bluetooth speaker. The FIFO sits a fixed
@@ -24,10 +24,10 @@
 #include <Preferences.h>
 #include <Wire.h>
 
-#include "hub_proto.h"
+#include "bus_proto.h"
 
 #ifndef TARGET_SPEAKER
-#define TARGET_SPEAKER "BikeAudio-Speaker"
+#define TARGET_SPEAKER "Resound-Speaker"
 #endif
 
 // I2C slave address (which speaker this board controls). Set per-env via build
@@ -305,7 +305,7 @@ void on_conn_state(esp_a2d_connection_state_t state, void *obj) {
 void setup() {
     Serial.begin(115200);
     delay(500);
-    Serial.printf("=== BikeAudio Source -> '%s' (FIFO delay, %ums cushion) ===\n",
+    Serial.printf("=== Resound Source -> '%s' (FIFO delay, %ums cushion) ===\n",
                   TARGET_SPEAKER, BASE_DELAY_MS);
 
     prefs.begin("bikeaudio", false);

src/bus_proto.h

@@ -1,5 +1,5 @@
 /**
- * BikeAudio — control-bus protocol shared by the S3 hub (I2C master) and the
+ * Resound — control-bus protocol shared by the S3 hub (I2C master) and the
  * source Boards B/C (I2C slaves). Included by both hub_s3.cpp and board_source.cpp.
  *
  * Bus: I2C. Hub = master. Each source board = a slave at a fixed address.

src/hud.cpp

@@ -1,5 +1,5 @@
 /**
- * BikeAudio — Hub (ESP32-S3-Touch-LCD-1.28) : PHASE 3 discovery + control
+ * Resound — Hub (ESP32-S3-Touch-LCD-1.28) : PHASE 3 discovery + control
  *
  * Round GC9A01 LCD + CST816S touch, wired as an I2C MASTER to the source
  * boards. Three brand-agnostic channels are controlled (discovery picks the
@@ -41,7 +41,7 @@
 #include <string.h>
 #include <LovyanGFX.hpp>
 #include <lvgl.h>
-#include "hub_proto.h"
+#include "bus_proto.h"
 
 class LGFX : public lgfx::LGFX_Device {
     lgfx::Panel_GC9A01    _panel;
@@ -861,7 +861,7 @@ static void poll_timer_cb(lv_timer_t *t) {
 void setup() {
     Serial.begin(115200);
     delay(300);
-    Serial.println("=== BikeAudio Hub — S3 LVGL UI ===");
+    Serial.println("=== Resound Hub — S3 LVGL UI ===");
 
     // Control bus: I2C master to the source boards on Wire1 (peripheral 1).
     // Peripheral 0 is used by the LovyanGFX CST816S touch (GPIO6/7).

src/sink.cpp

@@ -1,8 +1,8 @@
 /**
- * BikeAudio — Board A : A2DP SINK  ->  I2S MASTER
+ * Resound — Board A : A2DP SINK  ->  I2S MASTER
  *
  * Part of the 3-board relay. The iPhone connects to this board over Bluetooth
- * (A2DP name "BikeAudio"). This board decodes the audio to PCM and clocks it
+ * (A2DP name "Resound"). This board decodes the audio to PCM and clocks it
  * out on a shared I2S bus as the MASTER. Boards B and C (A2DP sources) listen
  * to this same bus as slaves and stream it to the JBL / Cardo speakers.
  *
@@ -64,7 +64,7 @@ void on_conn_state(esp_a2d_connection_state_t state, void *obj) {
 void setup() {
     Serial.begin(115200);
     delay(500);
-    Serial.println("=== BikeAudio Board A — A2DP SINK -> I2S master ===");
+    Serial.println("=== Resound Board A — A2DP SINK -> I2S master ===");
 
     start_i2s(44100);
 
@@ -72,9 +72,9 @@ void setup() {
     sink.set_stream_reader(write_pcm_to_i2s, false);
     sink.set_on_connection_state_changed(on_conn_state);
     sink.set_auto_reconnect(true);
-    sink.start("BikeAudio");
+    sink.start("Resound");
 
-    Serial.println("[SINK] Advertising 'BikeAudio' — connect from iPhone");
+    Serial.println("[SINK] Advertising 'Resound' — connect from iPhone");
 }
 
 void loop() {