I was looking for an opto-sensor in Mouser's catalog that was compatible with the one currently sourced from Farnell. Didn't find any good matches, although there was one you might be able to mount on the opposite side of the board if you bent a few pins.
The majority of these sensors have a two-pin phototransistor/photodarlington output. The one we specify has a three-pin open-collector output. The three-pin versions are a lot harder to find, and they're a bit more expensive too.
I don't know much about these sensors. Can someone explain why we chose the sensor we did? The only big difference I see is the three-pin sensors have a schmitt trigger built in, but a lot of the PIC's inputs are ST so I'm not sure that explains it.
I also saw the note on the universal controller board instructions: "R7 and R8 allow the use of non-standard opto-switches and are usually not needed; replace them with wire jumpers." What's this non-standard type of switch?
