Function esp_idf_svc::sys::adc_vref_to_gpio

source · 
pub unsafe extern "C" fn adc_vref_to_gpio(
    adc_unit: u32,
    gpio: i32,
) -> i32
Expand description

@brief Output ADC1 or ADC2’s reference voltage to adc2_channe_t’s IO.

This function routes the internal reference voltage of ADCn to one of ADC2’s channels. This reference voltage can then be manually measured for calibration purposes.

@note ESP32 only supports output of ADC2’s internal reference voltage. @param[in] adc_unit ADC unit index @param[in] gpio GPIO number (Only ADC2’s channels IO are supported)

@return - ESP_OK: v_ref successfully routed to selected GPIO - ESP_ERR_INVALID_ARG: Unsupported GPIO