Add A2DP sink (speaker) support (#2177)

Provide direct connection from BT audio to I2S and PWM audio outputs.
Example included showing play/pause operation.

Author: earlephilhower

libraries/BluetoothAudio/examples/A2DPSink/A2DPSink.ino

@@ -0,0 +1,59 @@
+// A2DPSink example - Released to the public domain in 2024 by Earle F. Philhower, III
+
+// Hook up a phono plug to GP0 and GP1 (and GND of course...the 1st 3 pins on the PCB)
+// Connect wired earbuds up and connect over BT from your phone and play some music.
+
+#include <BluetoothAudio.h>
+#include <PWMAudio.h>
+
+PWMAudio pwm;
+A2DPSink a2dp;
+
+volatile A2DPSink::PlaybackStatus status = A2DPSink::STOPPED;
+
+void volumeCB(void *param, int pct) {
+  (void) param;
+  Serial.printf("Speaker volume changed to %d%%\n", pct);
+}
+
+void connectCB(void *param, bool connected) {
+  (void) param;
+  if (connected) {
+    Serial.printf("A2DP connection started to %s\n", bd_addr_to_str(a2dp.getSourceAddress()));
+  } else {
+    Serial.printf("A2DP connection stopped\n");
+  }
+}
+
+void playbackCB(void *param, A2DPSink::PlaybackStatus state) {
+  (void) param;
+  status = state;
+}
+
+void setup() {
+  Serial.begin(115200);
+  delay(3000);
+  Serial.printf("Starting, connect to the PicoW and start playing music\n");
+  Serial.printf("Use BOOTSEL to pause/resume playback\n");
+  a2dp.setName("PicoW Boom 00:00:00:00:00:00");
+  a2dp.setConsumer(new BluetoothAudioConsumerPWM(pwm));
+  a2dp.onVolume(volumeCB);
+  a2dp.onConnect(connectCB);
+  a2dp.onPlaybackStatus(playbackCB);
+  a2dp.begin();
+}
+
+void loop() {
+  if (BOOTSEL) {
+    __lockBluetooth();
+    if (status == A2DPSink::PAUSED) {
+      a2dp.play();
+      Serial.printf("Resuming\n");
+    } else if (status == A2DPSink::PLAYING) {
+      a2dp.pause();
+      Serial.printf("Pausing\n");
+    }
+    __unlockBluetooth();
+    while (BOOTSEL);
+  }
+}

libraries/BluetoothAudio/examples/A2DPSource/A2DPSource.ino

@@ -4,6 +4,8 @@
 #include <BluetoothAudio.h>
 #include "raw.h"
 
+A2DPSource a2dp;
+
 int16_t pcm[64 * 2];
 uint32_t phase = 0;
 volatile uint32_t fr = 32;
@@ -39,7 +41,7 @@ void volumeCB(void *param, int pct) {
 void connectCB(void *param, bool connected) {
   (void) param;
   if (connected) {
-    Serial.printf("A2DP connection started to %s\n", bd_addr_to_str(A2DPSource.getSinkAddress()));
+    Serial.printf("A2DP connection started to %s\n", bd_addr_to_str(a2dp.getSinkAddress()));
   } else {
     Serial.printf("A2DP connection stopped\n");
   }
@@ -67,29 +69,29 @@ void fillPCM() {
 
 void setup() {
   delay(2000);
-  A2DPSource.onAVRCP(avrcpCB);
-  A2DPSource.onVolume(volumeCB);
-  A2DPSource.onConnect(connectCB);
-  A2DPSource.begin();
+  a2dp.onAVRCP(avrcpCB);
+  a2dp.onVolume(volumeCB);
+  a2dp.onConnect(connectCB);
+  a2dp.begin();
   Serial.printf("Starting, press BOOTSEL to pair to first found speaker\n");
   Serial.printf("Use the forward button on speaker to change tones\n");
   Serial.printf("Use the reverse button on speaker to alternate between tones and Au Claire De La Lune\n");
   Serial.printf("Use the play button on speaker to pause/unpause the tone\n");
 }
 
 void loop() {
-  while ((size_t)A2DPSource.availableForWrite() > sizeof(pcm)) {
+  while ((size_t)a2dp.availableForWrite() > sizeof(pcm)) {
     fillPCM();
-    A2DPSource.write((const uint8_t *)pcm, sizeof(pcm));
+    a2dp.write((const uint8_t *)pcm, sizeof(pcm));
   }
   if (BOOTSEL) {
     while (BOOTSEL) {
       delay(1);
     }
-    A2DPSource.disconnect();
-    A2DPSource.clearPairing();
+    a2dp.disconnect();
+    a2dp.clearPairing();
     Serial.printf("Connecting...");
-    if (A2DPSource.connect()) {
+    if (a2dp.connect()) {
       Serial.printf("Connected!\n");
     } else {
       Serial.printf("Failed!  :(\n");

libraries/BluetoothAudio/keywords.txt

@@ -6,15 +6,22 @@
 # Datatypes (KEYWORD1)
 #######################################
 
+BluetoothAudio	KEYWORD1
+BluetoothHCI	KEYWORD1
 A2DPSource	KEYWORD1
 BTDeviceInfo	KEYWORD1
+BluetoothAudioConsumer	KEYWORD1
+BluetoothAudioConsumerI2S	KEYWORD1
+BluetoothAudioConsumerPWM	KEYWORD1
+A2DPSink	KEYWORD1
 
 #######################################
 # Methods and Functions (KEYWORD2)
 #######################################
 begin	KEYWORD2
 end	KEYWORD2
 
+setConsumer	KEYWORD2
 setFrequency	KEYWORD2
 setName	KEYWORD2
 setsetBufferSize	KEYWORD2
@@ -26,14 +33,24 @@ connected	KEYWORD2
 disconnect	KEYWORD2
 clearPairing	KEYWORD2
 connect	KEYWORD2
-connect	KEYWORD2
-connect	KEYWORD2
+
+play	KEYWORD2
+stop	KEYWORD2
+pause	KEYWORD2
+fastForward	KEYWORD2
+rewind	KEYWORD2
+forward	KEYWORD2
+backward	KEYWORD2
+volumeUp	KEYWORD2
+volumeDown	KEYWORD2
+mute	KEYWORD2
 
 onTransmit	KEYWORD2
 onAVRCP	KEYWORD2
 onBattery	KEYWORD2
 onVolume	KEYWORD2
 onConnect	KEYWORD2
+onPlaybackStatus	KEYWORD2
 
 # BTDeviceInfo
 deviceClass	KEYWORD2
@@ -45,3 +62,6 @@ name	KEYWORD2
 #######################################
 # Constants (LITERAL1)
 #######################################
+STOPPED	LITERAL
+PLAYING	LITERAL
+PAUSED	LITERAL