HiCan I plug a led in pin 3 and 4 (with resistor) and set 4 to LOW and 3 to HIGH, will this light up the led or is it bad for the Arduino if you use an output pin as ground? And if i put them both tot HIGH, will the led go out?Thank you!
Not sure why you would want to do this. You could do it if you had a tricolour LED with only two leads but otherwise there seems to be no need.Do you think you are running out of ground pins? We have seen beginners think this is a problem as they don't realise you can connect more than one thing to a pin.