Just got a bag of these from a buddy of mine. Looks like a photointerrupter you might see in a mouse or for servo control. Anyone know what else they might be good for?


Looking for project ideas... lol

I have used similar devices for end stops on a CNC machine, to read a slotted disc in a wind speed gauge, to sense the movement of a tippy cup in a rain gauge, to sense the slots on a robot wheel encoder disc and more.

Thanks fungus. I’ve seen them being use as limit switches for a 3D printer. I think they could work as an optoisolator. Looks like something that will end up in my “extra” stuff box and may come in handy one day.

As far as wiring them, they are like an optoisolator. A current limitresistor for the LED side and that side can be powered all the time. I use the internal pullup on an input connected to the collector and ground the emitter of the phototransistor. Arduino input LOW when not blocked by something in the slot and HIGH when blocked.