ESP32 Forum

Code: Select all

void record_wav()
{
    static uint16_t i2s_readraw_buff[SAMPLE_SIZE];
    uint32_t rec_time=2;
    int flash_wr_size = 0;

    uint32_t flash_rec_time = BYTE_RATE * rec_time;

    printf("Record starting now....flash_rec_time = %d!!!!\n", flash_rec_time);
    // Start recording
    while (flash_wr_size < flash_rec_time) {
        // Read the RAW samples from the microphone
        i2s_read(CONFIG_EXAMPLE_I2S_CH, (char *)i2s_readraw_buff, SAMPLE_SIZE, &bytes_read, 100);

        for (int i=0; i < SAMPLE_SIZE/2; i++)
        {
            printf("%04x", (uint16_t)i2s_readraw_buff[i]);
        }

        flash_wr_size += bytes_read;
        vTaskDelay(50 / portTICK_PERIOD_MS);
    }

    while(1){
    	vTaskDelay(200 / portTICK_PERIOD_MS);
    }

    ESP_LOGI(TAG, "Recording done...... Uninstalling driver.....!");
    ESP_ERROR_CHECK( i2s_driver_uninstall(CONFIG_EXAMPLE_I2S_CH) );
}

void init_microphone(void)
{
    // Set the I2S configuration as PDM and 16bits per sample
    i2s_config_t i2s_config = {
        .mode = I2S_MODE_MASTER | I2S_MODE_RX | I2S_MODE_PDM,
        .sample_rate = CONFIG_EXAMPLE_SAMPLE_RATE,
        .bits_per_sample = I2S_BITS_PER_SAMPLE_16BIT,
        .channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
	.communication_format = I2S_COMM_FORMAT_STAND_MSB,
        .intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
        .dma_buf_count = 64,
        .dma_buf_len = 200,
        .use_apll = 0,
    };

    // Set the pinout configuration (set using menuconfig)
    i2s_pin_config_t pin_config = {
        .mck_io_num = I2S_PIN_NO_CHANGE,
        .bck_io_num = I2S_PIN_NO_CHANGE,
        .ws_io_num = CONFIG_EXAMPLE_I2S_CLK_GPIO,
        .data_out_num = I2S_PIN_NO_CHANGE,
        .data_in_num = CONFIG_EXAMPLE_I2S_DATA_GPIO,
    };

    // Call driver installation function before any I2S R/W operation.
    ESP_ERROR_CHECK( i2s_driver_install(CONFIG_EXAMPLE_I2S_CH, &i2s_config, 0, NULL) );
    ESP_ERROR_CHECK( i2s_set_pin(CONFIG_EXAMPLE_I2S_CH, &pin_config) );
//  ESP_ERROR_CHECK(i2s_set_pdm_rx_down_sample(I2S_NUM_0,I2S_PDM_DSR_16S) );
    ESP_ERROR_CHECK( i2s_set_clk(CONFIG_EXAMPLE_I2S_CH, CONFIG_EXAMPLE_SAMPLE_RATE, I2S_BITS_PER_SAMPLE_16BIT, I2S_CHANNEL_MONO) );
}

void lv_tick_task(void *arg)
{
    while(1)
    {
        vTaskDelay((200) / portTICK_PERIOD_MS);
    }
}

void app_main(void)
{
    ESP_LOGI(TAG, "PDM microphone recording Example start");

    // Init the PDM digital microphone
    init_microphone();
    ESP_LOGI(TAG, "Starting recording for %d seconds!", CONFIG_EXAMPLE_REC_TIME);
    // Start Recording
    xTaskCreate(lv_tick_task, "lv_tick_task", 1024, NULL, 1, NULL);
    xTaskCreate(record_wav, "i2s_pdm_rx_task", 4096*5, NULL, 5, NULL);
}