need help creating bluetooth speacker

[techexplorers123]

hi,
i created a bluetooth speacker using this lib it was easy to create but i have some problems that i need help fixing.

• how do i add audio feedback to things like device disconnected, device connected etc. tried but got nowhere.
  the code works but gets very pour audio after it played something. i'll post the code i tried below.
• i am using the internal DAC of esp32 with an 15w class D amp, when ever the playback is stopped / started there is a pop sound from the speacker. how to fix that?
  any help would be welcome. thanks.

#include "AudioTools.h"
#include "BluetoothA2DPSink.h"
#include "SPIFFS.h"

AnalogAudioStream out;
BluetoothA2DPSink a2dp_sink(out);
A2DPNoVolumeControl vc;
File audio_file;
EncodedAudioStream decoder(&out, new WAVDecoder());
StreamCopy copier_file(decoder, audio_file);
const String POWER_ON_SOUND = "/poweron.wav";
const String CONNECT_SOUND = "/connect.wav";
const String DISCONNECT_SOUND = "/disconnect.wav";

bool file_playing = false;

void playEventSound(String filename)
{
  if (SPIFFS.exists(filename))
  {
    audio_file = SPIFFS.open(filename);
    if (audio_file)
    {
      decoder.begin();
      file_playing = true;
    }
  }
}

void stopEventSound()
{
  if (file_playing)
  {
    audio_file.close();
    file_playing = false;
    decoder.end();
  }
}

void on_connection_state_changed(esp_a2d_connection_state_t state, void *ptr)
{
  if (state == ESP_A2D_CONNECTION_STATE_CONNECTED)
  {
    playEventSound(CONNECT_SOUND);
  }
  else if (state == ESP_A2D_CONNECTION_STATE_DISCONNECTED)
  {
    playEventSound(DISCONNECT_SOUND);
  }
}

void setup()
{
  SPIFFS.begin();
  a2dp_sink.set_on_connection_state_changed(on_connection_state_changed);
  a2dp_sink.set_auto_reconnect(true);
  a2dp_sink.set_volume_control(&vc);
  a2dp_sink.set_mono_downmix(true);
  playEventSound(POWER_ON_SOUND);
  delay(100);
  a2dp_sink.set_volume(150);
  a2dp_sink.start("esp32");
}

void loop()
{
  if (copier_file.copy() == 0)
  {
    stopEventSound();
  }
}

[pschatzmann]

There are several problems with your logic:

• playing a file might change the i2s audio info: so store it before you play the file and restore it back to the original state after playing.
• You can use the copyAll() method to play the whole file
• The BluetoothA2DPSink is writing the audio data to i2s in a task, so you have potentially 2 processes that write data to i2s which will mess up the output badly! I suggest you use the A2DPStream class to prevent this from happening.
• You will need to analyze where the pop sound is coming from: it might be the stopping and starting of the AnalogAudioStream. Using the A2DPStream might help here as well...

[techexplorers123]

hi,
thanks for the help. for those who are having the same problem, I'll post the code below.
the popping issue seams to be still there. I'll record it and post for better understanding.
hope someone can help me with that.
here is the recording. https://next.techclub.co.in/s/EaZ2dHaYkyK2YQg
to fix as @pschatzmann pointed out i copied the audio info before playing then created a null stream and redirected the a2dp audio to it to mute it and play the audio then restoring to copied info and switching it back to out.
now it's working well.

#include "AudioTools.h"
#include "BluetoothA2DPSink.h"
#include "SPIFFS.h"
AnalogAudioStream out;
NullStream nothing;
BluetoothA2DPOutputAudioTools audio;
BluetoothA2DPSink a2dp_sink(audio);

EncodedAudioStream decoder(&out, new WAVDecoder());

const String POWER_ON_SOUND = "/poweron.wav";
const String CONNECT_SOUND = "/connect.wav";
const String DISCONNECT_SOUND = "/disconnect.wav";

AudioInfo current_info;

void playEventSound(String filename)
{
  if (SPIFFS.exists(filename))
  {
    File f = SPIFFS.open(filename);
    current_info = out.audioInfo();
    audio.set_output(nothing);
    decoder.begin();
    StreamCopy copier(decoder, f);
    copier.copyAll();
    decoder.end();
    f.close();
    out.setAudioInfo(current_info);
    audio.set_output(out);
  }
}

void on_connection_state_changed(esp_a2d_connection_state_t state, void *ptr)
{
  if (state == ESP_A2D_CONNECTION_STATE_CONNECTED)
  {
    playEventSound(CONNECT_SOUND);
  }
  else if (state == ESP_A2D_CONNECTION_STATE_DISCONNECTED)
  {
    playEventSound(DISCONNECT_SOUND);
  }
}

void setup()
{
  SPIFFS.begin();
  a2dp_sink.set_on_connection_state_changed(on_connection_state_changed);
  a2dp_sink.set_auto_reconnect(true, 10);
  a2dp_sink.set_volume(150);
  playEventSound(POWER_ON_SOUND);
  a2dp_sink.set_mono_downmix(true);
  a2dp_sink.start("esp32");
}

void loop()
{
}