I have tried to put some white printer paper around the transistor to shield it from excess light. Do you think that a black shield works better?
Also I will be using 4 phototransistors, sorry the photo only shows 1. So, I can determine if a coin passes either 1, 2, 3, or all 4 transistors. However, if I have 4 phototransistors over each opening then they all trigger when any coin is sensed. So I am trying to find a transistor that will give me a digital 0 or 1 so that I can definitely know if a coin passes by the transistor.
I think the thing used in Robots is a Hall effect sensor, but I wasn't sure if that was going to work.