[HELP] Reading from I2S to WAV in stereo

[SvanteKaiser]

How can I read from I2S to WAV in stereo?

I have such I2S configuration:

Code: Select all

    BITS_PER_SAMPLE = I2S_BITS_PER_SAMPLE_16BIT;// I2S_BITS_PER_SAMPLE_32BIT;
    i2s_config_t i2s_config = {
      .mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_RX),
      .sample_rate = SAMPLE_RATE,
      .bits_per_sample = BITS_PER_SAMPLE,
      .channel_format = I2S_CHANNEL_FMT_RIGHT_LEFT,
      .communication_format = (i2s_comm_format_t)(I2S_COMM_FORMAT_I2S | I2S_COMM_FORMAT_I2S_MSB),
      .intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
      .dma_buf_count = 16,
      .dma_buf_len = 60,
    };

    i2s_pin_config_t pin_config;

    pin_config.bck_io_num = PIN_I2S_BCLK;
    pin_config.ws_io_num = PIN_I2S_LRC;
    pin_config.data_out_num = I2S_PIN_NO_CHANGE;
    pin_config.data_in_num = PIN_I2S_DIN;
    pin_config.mck_io_num = PIN_I2S_MCK;

    i2s_driver_install(I2S_NUM_0, &i2s_config, 0, NULL);
    i2s_set_pin(I2S_NUM_0, &pin_config);
    i2s_set_clk(I2S_NUM_0, SAMPLE_RATE, BITS_PER_SAMPLE, I2S_CHANNEL_STEREO);
    i2s_zero_dma_buffer(I2S_NUM_0);

And I have such recording method. But is records in mono. I am not sure, what does `wavData[j][2*i] = i2sBuffer[8*i + 2];` mean, but I am sure that I need to change this part.

Code: Select all

void Audio::Record() {
  CreateWavHeader(paddedHeader, wavDataSize);
  int bitBitPerSample = i2s->GetBitPerSample();
  if (bitBitPerSample == 16) {
    for (int j = 0; j < wavDataSize/dividedWavDataSize; ++j) {
      i2s->Read(i2sBuffer, i2sBufferSize/2);
      for (int i = 0; i < i2sBufferSize/8; ++i) {
        wavData[j][2*i] = i2sBuffer[4*i + 2];
        wavData[j][2*i + 1] = i2sBuffer[4*i + 3];
      }
    }
  }
}