I need to monitor a door of its use.
I am thinking of a reed switch & magnet on the door, connected to a RF transmitter with a receiver ~50 feet away, after that maybe record use somehow, or turn on a latching circuit to tell me that the door was used "today".
If it would be X10 through the power line (can do), I would surely want to give it its own house code.
Any ideas what would work best, and at a low cost?
Thanks!