ESP32 Forum

I can't find any useful description of how to use the ADC or the pre-amplifier despite tantalising hints. Is there anything?
It seems unfortunate for effort to have been put into these features without describing them.
I really don't want to have to reverse-engineer the chip to get use these features.

Ideally I would like to use the ADC with DMA to collect samples over some milliseconds. I can't figure out DMA either ...

Any help would be appreciated.

Ideally I would like to use the ADC with DMA to collect samples over some milliseconds. I can't figure out DMA either ...

Same for me, eagerly....(possible for Arduino?)

Yep, the ADC in it's current state is a broken toy.
Also, the WROOM32 module has no saparate VDDA pins sticking out and even worse it is directly connected to the VDD33 internally without any LC filtering.
It will limit the ADC capabilities significantly.