You might find this helpful. Two options: (1) a ceiling-mounted ultrasonic sensor to detect car is in a garage parking spot (not really what you're asking); and (2) an xbee device plugged into the USB port (a lot closer).
Good luck.....
You might find this helpful. Two options: (1) a ceiling-mounted ultrasonic sensor to detect car is in a garage parking spot (not really what you're asking); and (2) an xbee device plugged into the USB port (a lot closer).
Good luck.....