I was reading this and thought to myself, “If I have alot of time and no cash, this would be the way to go”. Why? It seems a bit clunky of a build. But, I have wheels, wood, micro-switches. So it would not cost anything. Me…I think I use use magnet sensors or something.
http://www.instructables.com/id/Automatic-Garage-Door-OpenClosed-Checker/