Added variable timer for play pos notification, RN_TRACK_CHANGE setter

README.md

@@ -179,7 +179,7 @@ before you start the A2DP sink. Note that data2 is actually a char* string, so e
 
 ### Support for Notifications
 
-Similarly to the `avrc_metadata_callback`, ESP IDF v4+ supports selected `esp_avrc_rn_param_t` callbacks like `set_avrc_rn_playstatus_callback` and `set_avrc_rn_play_pos_callback` which can be used to obtain `esp_avrc_playback_stat_t playback` playback status and `uint32_t play_pos` playback position respectively. See the playing_status_callbacks example for more.
+Similarly to the `avrc_metadata_callback`, ESP IDF v4+ supports selected `esp_avrc_rn_param_t` callbacks like `set_avrc_rn_playstatus_callback`, `set_avrc_rn_play_pos_callback` and `set_avrc_rn_track_change_callback` which can be used to obtain `esp_avrc_playback_stat_t playback` playback status,`uint32_t play_pos` playback position and `uint8_t elm_id` track change flag respectively. See the playing_status_callbacks example for more details.
 
 ### Support for AVRC Commands
 

examples/bt_music_receiver_playing_status_callbacks/bt_music_receiver_playing_status_callbacks.ino

@@ -17,7 +17,7 @@
 #include "BluetoothA2DPSink.h"
 
 I2SStream out;
-BluetoothA2DPSink a2dp_sink(i2s);
+BluetoothA2DPSink a2dp_sink(out);
 
 void avrc_rn_play_pos_callback(uint32_t play_pos) {
   Serial.printf("Play position is %d (%d seconds)\n", play_pos, (int)round(play_pos/1000.0));
@@ -48,10 +48,22 @@ void avrc_rn_playstatus_callback(esp_avrc_playback_stat_t playback) {
   }
 }
 
+void avrc_rn_track_change_callback(uint8_t *id) {
+  Serial.println("Track Change bits:");
+  for (uint8_t i = 0; i < 8; i++)
+  {
+    Serial.printf("\tByte %d : 0x%x \n",i,id[i]);
+  }
+  //An example of how to project the pointer value directly as a uint8_t
+  uint8_t track_change_flag = *id;
+  Serial.printf("\tFlag value: %d\n",track_change_flag);
+}
+
 void setup() {
   Serial.begin(115200);
   a2dp_sink.set_avrc_rn_playstatus_callback(avrc_rn_playstatus_callback);
-  a2dp_sink.set_avrc_rn_play_pos_callback(avrc_rn_play_pos_callback);
+  a2dp_sink.set_avrc_rn_play_pos_callback(avrc_rn_play_pos_callback,5); //Update the playing position every 5 seconds when Playing
+  a2dp_sink.set_avrc_rn_track_change_callback(avrc_rn_track_change_callback);
   a2dp_sink.start("MyMusic");
 }
 

src/BluetoothA2DPSink.cpp

@@ -741,8 +741,8 @@ void BluetoothA2DPSink::av_new_track() {
   if (esp_avrc_rn_evt_bit_mask_operation(ESP_AVRC_BIT_MASK_OP_TEST,
                                          &s_avrc_peer_rn_cap,
                                          ESP_AVRC_RN_TRACK_CHANGE)) {
-    esp_avrc_ct_send_register_notification_cmd(APP_RC_CT_TL_RN_TRACK_CHANGE,
-                                               ESP_AVRC_RN_TRACK_CHANGE, 0);
+    esp_avrc_ct_send_register_notification_cmd(
+      APP_RC_CT_TL_RN_TRACK_CHANGE, ESP_AVRC_RN_TRACK_CHANGE, 0);
   }
 #endif
 }
@@ -766,7 +766,7 @@ void BluetoothA2DPSink::av_play_pos_changed(void) {
                                          &s_avrc_peer_rn_cap,
                                          ESP_AVRC_RN_PLAY_POS_CHANGED)) {
     esp_avrc_ct_send_register_notification_cmd(
-        APP_RC_CT_TL_RN_PLAY_POS_CHANGE, ESP_AVRC_RN_PLAY_POS_CHANGED, 10);
+        APP_RC_CT_TL_RN_PLAY_POS_CHANGE, ESP_AVRC_RN_PLAY_POS_CHANGED, notif_interval_s);
   }
 #endif
 }
@@ -783,7 +783,13 @@ void BluetoothA2DPSink::av_notify_evt_handler(uint8_t event_id,
   switch (event_id) {
     case ESP_AVRC_RN_TRACK_CHANGE:
       ESP_LOGD(BT_AV_TAG, "%s ESP_AVRC_RN_TRACK_CHANGE %d", __func__, event_id);
-      av_new_track();
+      av_new_track();    
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(4, 0, 0)
+      // call avrc track change notification callback if available
+      if (avrc_rn_track_change_callback != nullptr) {
+        avrc_rn_track_change_callback(event_parameter->elm_id);
+      }
+#endif
       break;
     case ESP_AVRC_RN_PLAY_STATUS_CHANGE:
       ESP_LOGD(BT_AV_TAG, "%s ESP_AVRC_RN_PLAY_STATUS_CHANGE %d, to %d",

src/BluetoothA2DPSink.h

@@ -226,11 +226,18 @@ class BluetoothA2DPSink : public BluetoothA2DPCommon {
       void (*callback)(esp_avrc_playback_stat_t playback)) {
     this->avrc_rn_playstatus_callback = callback;
   }
-  /// Define a callback method which provides esp_avrc_rn_param_t play position notifications
+  /// Define a callback method which provides esp_avrc_rn_param_t play position notifications, at a modifiable interval over 1s
   virtual void set_avrc_rn_play_pos_callback(
-      void (*callback)(uint32_t play_pos)) {
+      void (*callback)(uint32_t play_pos),uint32_t notif_interval) {
     this->avrc_rn_play_pos_callback = callback;
+    this->notif_interval_s = max(notif_interval,(uint32_t)1);
   }
+  /// Define a callback method which provides an 8bit array for track change notifications 
+  /// Typically the last bit is 1 when there is a track change (so can be cast to a uint8_t)
+  virtual void set_avrc_rn_track_change_callback(
+      void (*callback)(uint8_t *id)) {
+    this->avrc_rn_track_change_callback = callback;
+    }
 #endif
 
   /// Defines the method which will be called with the sample rate is updated
@@ -419,7 +426,9 @@ class BluetoothA2DPSink : public BluetoothA2DPCommon {
   void (*avrc_metadata_callback)(uint8_t, const uint8_t *) = nullptr;
 #if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(4, 0, 0)
   void (*avrc_rn_playstatus_callback)(esp_avrc_playback_stat_t) = nullptr;
+  void (*avrc_rn_track_change_callback)(uint8_t *) = nullptr;
   void (*avrc_rn_play_pos_callback)(uint32_t) = nullptr;
+  uint32_t notif_interval_s = 10;
 #endif
   void (*avrc_rn_volchg_complete_callback)(int) = nullptr;
   bool (*address_validator)(esp_bd_addr_t remote_bda) = nullptr;