N.B. you do not necessarily get a range all the way to 3.3V VCC!!!! On the ESP32S2 using adc_cali_raw_to_voltage() the max voltage we could read was 2.643V with atten = ADC_ATTEN_DB_11 The ESP32 has an AtoD Vref of approx 1.1V, but this is nominal and it can be in the range 1.0 to 1.2V. An […]

Documentation https://docs.espressif.com/projects/esp-idf/en/latest/esp32s3/api-reference/peripherals/adc_oneshot.html Hardware Limitations Note that ADC1 and ADC2 usage are shared by some peripherals, such as the random number generator and WiFi. Speed adc_oneshot_read() was fast in our tests, taking approx 130uS on an ESP32 S3 Example setting up, with calibration and performing a read Example function that uses as simple averaging filter Disable […]