Ouput from NodeMCU pin as input to Arduino Nano Answered
I have a NodeMCU ESP-12E with D7 (output) connected in series with 220R resister to pin 12 (input) on Arduino Nano.
Looks something like the image (fritzing doesn't seem to have my exact device)
Is this a safe circuit? If not - what would make it safe?
It seems to work but I don't want to fry anything.
What I am doing is using the 5V output on the Nano to operate a relay. The NodeMCU only seems to have 3v output which does not seem to be enough to operate my relay. Maybe there's a better way to get this done?