Thank you for your fast reply. I have been working through the XOD tutorials but not everything is “sticking with me” the first time around. I am basically trying to recreate the tutorial found linked below with XOD: https://jrowing.com/arduino-light-gates . I tried your suggestion and I am not getting the results I expected. I was hoping to get the led to go off when the beam is broken and be on when the beam is intact. All I get are some random flutters in the led when I pass my finger through the beam