sorry I meant phototransistor, not photodiode. Ok, call me paranoid. but I did happen to run more tests and sometimes the tests work and sometimes they dont. I'm gonna try to shield the side of these phototransistors since there are LEDs and 7-segment displays on the same board that sometimes light up. The LEDs are right next to the phototransistors (even touching them). so now I need to find a decent LED insulator that isn't too fat and the only thing I can think of which is unprofessional is wrapping the phototransistor sides up with electrical tape.