ADC Microphone
===============
:link_to_translation:`zh_CN:[中文]`

Using ADC to capture analog microphone data eliminates the need for an external audio codec chip, making it suitable for applications that do not require high sampling rates and are cost-sensitive. The code structure follows the engineering model of `esp_codec_dev <https://components.espressif.com/components/espressif/esp_codec_dev>`__.

Features
---------

- Supports multi-channel ADC audio sampling.
- Supports up to 12-bit ADC sampling resolution.

.. note:: The maximum resolution for multi-channel sampling is determined by the ADC's maximum sampling rate (83.3K for ESP32-S3) divided by the number of sampling channels.

Reference Circuit
------------------

External Configuration for ADC Continuous
------------------------------------------

You can initialize the ADC continuous mode externally and pass in an ``adc_continuous_handle_t``.

.. code:: c

    adc_continuous_handle_t handle;
    adc_continuous_handle_cfg_t adc_config = {
        .max_store_buf_size = adc_cfg->max_store_buf_size,
        .conv_frame_size = adc_cfg->conv_frame_size,
        .flags.flush_pool = true,
    };

    adc_continuous_new_handle(&adc_config, &handle);

Using with ADC Oneshot Mode
----------------------------

- If ADC oneshot and ADC continuous use different ADC units, there will be no conflicts.

- If they use the same ADC unit, make sure to call ``esp_codec_dev_close()`` to close ``adc_mic`` before calling ``adc_oneshot_read``.

.. code:: c

    adc_continuous_start(handle);
    adc_continuous_read();
    adc_continuous_stop();
    adc_oneshot_read();

Example Code
-------------

.. code:: c

    audio_codec_adc_cfg_t cfg = DEFAULT_AUDIO_CODEC_ADC_MONO_CFG(ADC_CHANNEL_0, 16000);
    const audio_codec_data_if_t *adc_if = audio_codec_new_adc_data(&cfg);

    esp_codec_dev_cfg_t codec_dev_cfg = {
        .dev_type = ESP_CODEC_DEV_TYPE_IN,
        .data_if = adc_if,
    };
    esp_codec_dev_handle_t dev = esp_codec_dev_new(&codec_dev_cfg);
    esp_codec_dev_sample_info_t fs = {
        .sample_rate = 16000,
        .channel = 1,
        .bits_per_sample = 16,
    };
    esp_codec_dev_open(dev, &fs);
    uint16_t *audio_buffer = malloc(16000 * sizeof(uint16_t));
    assert(audio_buffer);
    while (1) {
        int ret = esp_codec_dev_read(dev, audio_buffer, sizeof(uint16_t) * 16000);
        ESP_LOGI(TAG, "esp_codec_dev_read ret: %d\n", ret);
    }

API Reference
--------------

.. include-build-file:: inc/adc_mic.inc