Quote Originally Posted by Mike Dodd View Post
Thanks, Brian. I originally planned to use an ultrasound distance measuring device on an Arduino to detect at-park, but decided on magnetic switches instead.

My original level of paranoia was to shut off AC power to the garage door opener (remotely, from inside the house) while imaging, and turn it on afterward. But when powered-up and commanded to move the roof, the stupid opener starts to move it toward the OPEN position. Naturally, this stalls because the roof is already open (and the opener's magnetic switch knows this), and a second press of the button causes the roof to close. Sadly, the Foster board doesn't have a way to do a second relay closure. So the only way to ensure automated shutdown is to leave the power on for the whole session.

I think I'll stick with the second set of at-park switches in series with the Foster board's connection to the opener. It's difficult to think of a failure mode that will cause the roof to close if the hard-wired pushbutton loop is open.

--- Mike
http://astronomy.mdodd.com

I had the same problem, I'm going to upgrade the motor to the one advertised by the same company that does SkyAlert, so you command the direction instead of command a motion.