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static const char *TAG = "example";
#define BUFF_SIZE 2048
i2s_chan_handle_t tx_handle;

void i2s_init(void)
{

    i2s_chan_config_t chan_cfg = I2S_CHANNEL_DEFAULT_CONFIG(I2S_NUM_0, I2S_ROLE_MASTER);
    ESP_LOGI(TAG, "I2S Channel Config Frame number %lu", chan_cfg.dma_frame_num);

    ESP_ERROR_CHECK(i2s_new_channel(&chan_cfg, &tx_handle, NULL));
    i2s_std_config_t i2s_cfg = {
        .clk_cfg = I2S_STD_CLK_DEFAULT_CONFIG(16000),
        .slot_cfg = I2S_STD_MSB_SLOT_DEFAULT_CONFIG(I2S_DATA_BIT_WIDTH_16BIT, I2S_SLOT_MODE_STEREO),
        .gpio_cfg = {
            .mclk = I2S_GPIO_UNUSED,
            .bclk = GPIO_NUM_3,
            .ws = GPIO_NUM_2,
            .dout = GPIO_NUM_9,
            .din = GPIO_NUM_19,
            .invert_flags = {
                .mclk_inv = false,
                .bclk_inv = false,
                .ws_inv = false,
            },
        }};
    ESP_ERROR_CHECK(i2s_channel_init_std_mode(tx_handle, &i2s_cfg));
}

Code: Select all

void play_wav_file(void)
{
    dumb_wav_header_t wave_header;
    FILE *f = fopen("/spiffs/payment.wav", "r");
    if (f == NULL)
    {
        ESP_LOGE(TAG, "Failed to open the payment.wav");
    }

    size_t read;
    fread(&wave_header, sizeof(wave_header), 1, f);
    ESP_LOGI(TAG, "Number of channels: %u", wave_header.num_channels);
    ESP_LOGI(TAG, "Bits per sample: %u", wave_header.bits_per_sample);
    ESP_LOGI(TAG, "Sample rate: %lu", wave_header.sample_rate);
    ESP_LOGI(TAG, "Data size: %lu", wave_header.data_size);

    if (wave_header.bits_per_sample != 16)
    {
        ESP_LOGE(TAG, "Only 16 bit per sample is supported");
        return;
    }

    if (wave_header.num_channels != 2)
    {
        ESP_LOGE(TAG, "Only 2 channels are supported");
        return;
    }

    lseek(f, sizeof(dumb_wav_header_t), SEEK_SET);

    uint32_t number_of_samples = (8 * wave_header.data_size) / 8;
    ESP_LOGI(TAG, "Number of samples: %lu", number_of_samples);

    uint32_t size_of_sample = (wave_header.num_channels * wave_header.bits_per_sample) / 8;
    ESP_LOGI(TAG, "Sample Size: %lu", size_of_sample);

    uint8_t *w_buf = (uint8_t *)calloc(1, BUFF_SIZE);
    assert(w_buf);

    size_t w_bytes = BUFF_SIZE;

    while (1)
    {
        int read_bytes = fread(&w_buf, sizeof(w_buf), 1, f);
        if (read_bytes <= 0)
        {
            ESP_LOGI(TAG, "No more data to read");
            return;
        }

        i2s_channel_write(tx_handle, w_buf, BUFF_SIZE, &w_bytes, 1000);
    }
}