How to connect a garage door photo eye to a micro?
I am looking at hooking up an old photo eye from a garage door to a micro. The end use will be in a device to detect if my dog is about to jump over the fence and take a picture as well as play some audio of me telling him to get down. The problem is that I don't know the correct way to connect the photo eye to the micro. I believe the transmitter site should be powered with 12V, but I would rather know for sure before frying the sensor. My garage door opener doesn't have a port for the photo eyes, so I can't check the outputs on it, but I was hoping someone here might already know, or might investigate their own open. Thanks for any help.