Function esp_idf_svc::sys::adc1_config_channel_atten

pub unsafe extern "C" fn adc1_config_channel_atten(
    channel: u32,
    atten: u32,
) -> i32

@brief Set the attenuation of a particular channel on ADC1, and configure its associated GPIO pin mux.

The default ADC voltage is for attenuation 0 dB and listed in the table below. By setting higher attenuation it is possible to read higher voltages.

Due to ADC characteristics, most accurate results are obtained within the “suggested range” shown in the following table.

+----------+-------------+-----------------+
|          | attenuation | suggested range |
|    SoC   |     (dB)    |      (mV)       |
+==========+=============+=================+
|          |       0     |    100 ~  950   |
|          +-------------+-----------------+
|          |       2.5   |    100 ~ 1250   |
|   ESP32  +-------------+-----------------+
|          |       6     |    150 ~ 1750   |
|          +-------------+-----------------+
|          |      11     |    150 ~ 2450   |
+----------+-------------+-----------------+
|          |       0     |      0 ~  750   |
|          +-------------+-----------------+
|          |       2.5   |      0 ~ 1050   |
| ESP32-S2 +-------------+-----------------+
|          |       6     |      0 ~ 1300   |
|          +-------------+-----------------+
|          |      11     |      0 ~ 2500   |
+----------+-------------+-----------------+

For maximum accuracy, use the ADC calibration APIs and measure voltages within these recommended ranges.

@note For any given channel, this function must be called before the first time adc1_get_raw() is called for that channel.

@note This function can be called multiple times to configure multiple ADC channels simultaneously. You may call adc1_get_raw() only after configuring a channel.

@param channel ADC1 channel to configure @param atten Attenuation level

@return - ESP_OK success - ESP_ERR_INVALID_ARG Parameter error