How to apply BEEP-signal to the Output Stream when you NOT HAVING THE MASTER SIGNAL from BluetoothA2DPSink

[Knottis]

Hi!

How to apply BEEP-signal to the Output Stream when you NOT HAVING THE MASTER SIGNAL from BluetoothA2DPSink.

Mixer works when you have signals on «both» inputs. But when you stop the BLT signal, you no longer have an output signal on the i2s. So here BLT is the master signal that controls the output signal.

But I want to send out a beep when I also don't have this master signal, how do I do this?...

Have tried several methods of sending a BEEP-signal out on the i2c bus when I NOT having the master streaming music signal.

• Nr-1 Mixer the Master signal (BLT) and SineWave is -OK.

• But not the Nr-2 «Play Police-Alarm»… To indicates that it is not a input BLT signal.. (Have not a bluetooth signal from my guitar).

How can I do this correctly!..

Have a nice day 😀

---

My code from my last attempt to send out a BEEP signal when I don't have a Master-BLT signal♬🎸...

#include <BluetoothA2DPSink.h>
#include <AudioTools.h>

#define I2S_PORT I2S_NUM_0          

BluetoothA2DPSink a2dp_sink;        // Music Receiver
I2SStream OutI2S;                   // Access I2S as stream

static i2s_config_t i2s_config = {
  .mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_TX),
  .sample_rate = 44100, 
  .bits_per_sample = (i2s_bits_per_sample_t)32,
  .channel_format = I2S_CHANNEL_FMT_RIGHT_LEFT,
  .communication_format = (i2s_comm_format_t)(I2S_COMM_FORMAT_STAND_I2S),
  .intr_alloc_flags = 0, 
  .dma_buf_count = 4,
  .dma_buf_len = 1024,
  .use_apll = true,
  .tx_desc_auto_clear = true  // Avoiding noise in case of data unavailability
};

char BLTNAME[20] = "GuitarSpeaker";  

static int BluetoothVolume = 60; 

// Apply Effects on an Input Stream
AudioInfo info(44100, 2, 16);             
SineWaveGenerator<int16_t> sineWave(10000);          
GeneratedSoundStream<int16_t> Sound(sineWave);        

// Nr-1 MIXER - BluetoothA2DPSink and the Sound-SineWave
OutputMixer<int16_t> mixer(OutI2S, 2);              
const int buffer_size = 128;                            
uint8_t sound_buffer[buffer_size];

//-------------------------------------------------------------------------------------------
// Nr-2 PLAY POLICE-ALARM
StreamCopy copier(OutI2S, Sound);        // ♬🎸 Not Bluetooth signal from the Guitar!...
//-------------------------------------------------------------------------------------------


// Copies Sound to OutI2S => BLUETOOTH and SINEWAVE
// Write data to mixer
void read_data_stream(const uint8_t *A2DPdata, uint32_t length) {
  // To keep the mixing buffer small we split up the output into small slices
  int count = length / buffer_size + 1;
  for (int j = 0; j < count; j++) {
    const uint8_t *start = A2DPdata + (j * buffer_size);
    const uint8_t *end = min(A2DPdata + length, start + buffer_size);
    int len = end - start;
    if (len > 0) {
      // write a2dp slice
      mixer.write(start, len);
      // write sine tone with identical length
      Sound.readBytes(sound_buffer, len);
      mixer.write(sound_buffer, len);
    }
  }
}


void setup() {

  a2dp_sink.set_i2s_port(I2S_PORT);   
  a2dp_sink.set_i2s_config(i2s_config); 

  // Register data callback for - SINWAVE
  a2dp_sink.set_stream_reader(read_data_stream, false);
  
  // Setup Output mixer with min necessary memory
  mixer.begin(buffer_size);
 
  // Setup sineWave - Start 0-Hz = OFF
  sineWave.begin( info, 0 );             

  // Start i2s
  auto config = OutI2S.defaultConfig();
  config.copyFrom(info);
  config.pin_data = 2; 
  config.pin_bck = 32; 
  config.pin_ws = 33;

  config.buffer_count = 8;
  config.buffer_size = 256;

  OutI2S.begin(config);

  // Start Bluetooth Audio Receiver
  a2dp_sink.start(BLTNAME, true); 
  a2dp_sink.set_volume(BluetoothVolume); 

}




void loop() {
  //------------------------------------------------------------------------------------------------------
  // Apply BEEP-signal to the Output Stream when YOU NOT HAVING THE MASTER SIGNAL from BluetoothA2DPSink ♬🎸
  //------------------------------------------------------------------------------------------------------ 
  if( a2dp_sink.get_audio_state() == false ){
    // PLAY_POLICE_ALARM 
    int i = 0;
    for(i=635; i<912; i++){
      sineWave.setFrequency(i);
     //################## REBOOT - ERROR ##################
     copier.copy();    //  PUFF...PUFF...BANG.. ♬🎸 Not Bluetooth signal from the guitar!...
     //####################################################
      delay(10);
    }    
    for(i=912; i>635; i--){
      sineWave.setFrequency(i);
     //################## REBOOT - ERROR ##################
     copier.copy();    //  PUFF...PUFF...BANG.. ♬🎸 Not Bluetooth signal from the guitar!...
     //####################################################
      delay(10);
    }
  }
  //------------------------------------------------------------------------------------------------------ 
  else{
    // To test the mixer - signal!... - OK
    sineWave.setFrequency(N_B4);     // ♬🎸 Bluetooth signal from the guitar.
    delay(1000);
    sineWave.setFrequency(0);
  }
  delay(20000);
}


/* ( THE END ) */

[pschatzmann]

Strange question: but with many solutions.

1. In this case just don't use the mixer and just copy the data from the input to the output
2. Just write the 1 output and call flush output on the OutputMixer
3. call begin on the OutputMixer with 1 and just write the 1 output that you want to keep
4. Keep the OutputMixer with 2 outputs and replace the output with one from a SilenceGenerator

[Knottis]

👍Thanks for reply

Function Nr-1 «Apply Effects on an Input Stream -MIXER» works as I want. Mix the BLT- signal and the sine/tone signal - OK.

But Nr-2 «Police-Alarm» where I come up with my third signal that I want to send out on the i2s-bus that will not work. It is this extra signal that I want to somehow connect to the other signals on the i2s-bus as a independent beep!..
(♬🎸 Not Bluetooth signal from the guitar!...)

How can I connect this third signal to these, but regardless of the master signal from the BLT?..

😉 Hope you have a smart solution to this!
Thanks

---

😟I have also tried this!..

// Nr-2 PLAY POLICE-ALARM 
OutputMixer<int16_t> mixer2(OutI2S, 1);                   // Output mixer with 1 - outputs mixing to AudioKitStream 
StreamCopy copier(mixer2, Sound);                         // Copies Sound into i2s -> POLICE ALARM 

...
mixer2.begin();

... 
if( a2dp_sink.get_audio_state() == false ){
    // PLAY_POLICE_ALARM 
    copier.copy();    //  PUFF...PUFF...BANG.. ♬🎸 Not Bluetooth signal from the guitar!...

[pschatzmann]

I am sorry, but I am not here to debug your code!

Your sketch is a mess

• a2dp_sink.set_i2s_config(i2s_config); does not make any sense and is not used
• you can't use delays in the audio loop: Read the introduction again, it seems that you missed the most important points. Try to figure out yourself what the impact of a delay() on the audio output is...
• You can't copy to a destination in multiple tasks at the same time. So make sure that you either use the copy in the loop or the data copy in A2DP callback. But never do this at the same time!

Finally please also follow these recommendations: https://github.com/pschatzmann/arduino-audio-tools/wiki/It's-not-working
!