ESP32 Forum

It looks like the ADC on the S31 is intended for differential operation. I couldn't find much information about single ended measurement besides this:

A specific ADC unit can only work under one operating mode at any one time, either continuous mode or one-shot mode. adc_continuous_start() has provided the protection. In single-ended mode, if the N-side channel is used as the input interface, its raw-data polarity is inverted. For an input range of -2 V to 2 V, the N-side raw code is 4393 to 0. Please use the ADC calibration APIs.

I understand that measurements will be inverted but I don't understand the -2V to 2V figures. Is it possible to use p and n channels for single ended measurements in the range of 0V to VREF_ADC (3V3 on the WROOM-3) so that I can do 8 single ended measurements in this range on each of the ADCs (16 in total)?

Thanks a lot.