Unfortunatelly my Spruino Wifi just died today. I connected it to the 5V USB port of my computer and flashed the firmware to have a clean system and do some tests. It was very hot. After 10 minutes it switched off and never came back.
Voltage of the USB port is normal and I also tryed other 5V wall adaptors.
I probably did something wrong while playing with the voltage divider, maybe I applied 12V directly to a pin, or made a short, don't know. I must say that it has survived many other mistakes I made (as I am learning electronics) so the board is pretty strong and this is absolutelly not a complain.
Just in case it is interesting to you, this is the info I have:
Before dying, I measured 88ºC at the regulator and 50ºC at the chip. The system booted and worked right, maybe a bit slow, but the wifi and my http server worked. Digital pin outputs also worked.
While feeding with 5V, the 350 mA power draw was continuous with Wifi on. I remember that I measured 150 mA before the day it started to get hot, so I think that the heat came from the extra 200 mA.
While feeding it with 3.3V, power draw was 280 mA with Wifi, less temperature but still high.
When it died nothing else was connected to pins and system was clean, no programs, but heat and power consumption was the same.
Thanks for your support!