Calibrating ADC

[arao23]

I read that analog inputs are nonlinear on the ESP32, and therefore we will have to manually calibrate it. How do we calibrate the ESP32 so that the values are read in correctly? I didn't have this problem in the proof-of-concept arduino project.

[arao23]

Bump! Any updates on this?

Maybe I should switch over to 8266 until 32 is more mature. It may not be viable for production use if ADC is nonlinear :/

[StefanRvO]

I second this.
I will be using the ESP32 in a project this spring, which will involve the using the integrated ADC.
Are you able to provide some kind of documentation on the non-linearity of the ADC?

[WiFive]

It looks pretty linear up to 2.5v.

https://mobile.twitter.com/ba0sh1/statu ... 5816129536

[arao23]

Thanks, that's not as nonlinear as I fretted, good to know.

[jaegertuning]

I'm assuming the DAC is not linear either? I was testing it and a voltage sent to the ADC from an external sensor was a bit higher than if the same value is sent through the DAC