ESP-WROOM-32UE and I2S Configuration

[webzoid]

I'm trying to figure out how to configure the I2S peripheral on an ESP-WROOM-32UE module so as to stream stereo audio from a Texas Instruments TLV320ADC5140 device.

At present, I have configured the TLV320ADC to enable only one single stereo channel (with two PDM microphones connected) and as far as I can tell (both reading back the I2C registers and looking at the waveforms), it is up and running correctly. The PDMCLK is correctly generated and I can also see PDM data.

I've used the following configuration structs to set up the I2S:

Code: Select all

#define SAMPLE_BUFFER_SIZE      512
#define SAMPLE_RATE             8000s

//#define I2S_MIC_CHANNEL I2S_CHANNEL_FMT_RIGHT_LEFT
#define I2S_MIC_CHANNEL I2S_CHANNEL_FMT_ONLY_RIGHT

#define I2S_MIC_BITS_PER_SAMPLE I2S_BITS_PER_SAMPLE_32BIT

#define I2S_MIC_FORMAT  I2S_COMM_FORMAT_I2S
//#define I2S_MIC_FORMAT  I2S_COMM_FORMAT_PCM

#define I2S_MIC_SERIAL_CLOCK GPIO_NUM_21
#define I2S_MIC_LEFT_RIGHT_CLOCK GPIO_NUM_25
#define I2S_MIC_SERIAL_DATA GPIO_NUM_27

// don't mess around with this
i2s_config_t i2s_config = {
    .mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_RX),
    .sample_rate = SAMPLE_RATE,
    .bits_per_sample = I2S_MIC_BITS_PER_SAMPLE,
    .channel_format = I2S_MIC_CHANNEL,
    .communication_format = I2S_MIC_FORMAT,
    .intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
    .dma_buf_count = 4,
    .dma_buf_len = 1024,
    .use_apll = false,
    .tx_desc_auto_clear = false,
    .fixed_mclk = 0
};

i2s_pin_config_t i2s_mic_pins = {
    .bck_io_num = I2S_MIC_SERIAL_CLOCK,
    .ws_io_num = I2S_MIC_LEFT_RIGHT_CLOCK,
    .data_out_num = I2S_PIN_NO_CHANGE,
    .data_in_num = I2S_MIC_SERIAL_DATA
};

void setup()
{
  /* set up the I2S bus */
  i2s_driver_install(I2S_NUM_0, &i2s_config, 0, NULL);
  i2s_set_pin(I2S_NUM_0, &i2s_mic_pins);
  //i2s_set_clk(I2S_NUM_0, 16000, I2S_BITS_PER_SAMPLE_32BIT, I2S_CHANNEL_STEREO);
}

The above configuration allows me to hear only mono audio (due to I2S_MIC_CHANNEL) however if I enable both right and left channels, I still only receive right channel audio - I never receive stereo audio.

It's a long shot and I know I've not provided much details above. Has anyone encountered anything similar either using a similar audio codec such as the TLV320ADC?

Thanks in advance.