uint32_t reading = adc1_get_raw(ADC1_CHANNEL_5); uint32_t voltage = esp_adc_cal_raw_to_voltage(reading, adc_chars); Yes, I am using the above, but it is still inaccurate. It brings me only slightly close to what I am actually reading with a voltmeter. My job aim is to get as closed as possible to t...

@oldndumb, completely agree with you. ESP32 ADC is completely inaccurate. eFuse value is closer to actial voltage refference, but still useless. Not only eFuse, actually red Refference Voltage cannot really be used. The only more or les working ESP32 ADC calibration methode I have found so far is be...

@oldndumb , I could not understand how you convert REG_GET_FIELD to human readable values. But at most, for what reason do you read eFuse and how do you use the data. Also, what is you methode to calibrate ADC?

@oldndumb, I was wondering, what do you need the voltage refference for and how do you calibrate ADC?

@oldndumb, I am using your function. All works for me just fine. All ESP-IDF works good for me on Arduino and Platform IO. Also wondering, why do you need to read the eFuse voltage reference and how do you use it? I have mesured the actual ESP32 internal reference voltage on a few boards and results...

@oldndumb, I love your sketch, but do not yet understand how it works. Could you maybe explain? Below what I was using to read Vref : #include "esp_adc_cal.h" void setup() { Serial.begin(115200); while (!Serial) {} //Read eFuse Voltage Refference esp_adc_cal_characteristics_t adc_chars; //declaring ...