https://www.adafruit.com/images/product ... N_v4.3.pdf
But it would be better if you simply manage to have a VMax of 1V.
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.
I've same value elsewhere before but can't remember where....