I found that using analogRead(1) on Arduino gives unexpected results out of the box. Connecting GPIO1 (ADC1_CH0) to VCC/2 (1.65V) results in a value of 8191 (instead of around 2047 as expected for a 12 bit result at half-scale). After reading the documentation, I understand that after reset ADC1 is ...

I came across the same problem with a ESP32-S2-WROVER, mounted on the ESP32-S2-Saola-1 development module. I guess the DAC is the same as in the original ESP32. Using a 10K load to GND gives a linear response, no curvature at the high end with the 220 ohm load as pictured above. So, if you need to s...