Post links and attach files for documentation here, also chat about these docs freely

User avatar
By Electroguard
#29240 Hi. I have read that the Analog 'working' range is 0 to 1v, but I can't find any mention of absolute Max V for the ADC pin, so does anyone know if it would be the same as the other pins and therefore able to take 3.3v without suffering damage?
User avatar
By Electroguard
#29271 Thanks for the reply. I've already looked through those Expressif Specs but couldn't find it mentioned, hence the question.

And yes, of course I could restrict the ADC to 1v and not have such problems, but I am creating a Smart Socket hack tutorial for swaping out the original wifi module and replacing with an ESP-12 (or 07) for using Souliss on Arduino framework, and I wish to provide re-flashing capability via its USB charging socket using the 2 unused data+ and data- pins, but also to provide facility for plug-in external sensors into the USB socket.

I have already got 2 GPIOs to pair up and work with TX and RX over the 2 wires without conflict, because only 1 of each pair is ever active depending on whether in normal or flashing mode, but it would be a good bonus to be able to connect up ADC also, so that either a digital or analog sensor could be plugged into the USB socket with requiring any dismantling or re-wiring.

I suspect the ADC 1v is a function of the analog reference voltage and ADC range rather than an actual electronic limitation, and provided that Analog In doesn't rise above the chip supply voltage then hopefully it shouldn't do any damage, but it would have been nice to see ADC Vmax specified somewhere to be sure, because even if it works ok for me it might still cause problems for others.
User avatar
By al1fch
#30125 Adafruit says 1.8V max (electrical) for ADC input on Huzzah 8266 page
I've same value elsewhere before but can't remember where....