I have Raspberry running a very simple blink-led program:
Raspberry GPIO21 ---->resistor----->[led +/led -]---->Raspberry ground
It works fine.
Now I'd like to use Arduino pin 2 to DigitalRead above led status: is it on or off? Where do I connect wires.
Sorry about if this is very simple - I had a long hiatus from Arduino programming and I am re-learning all again.