Usually the kits come with one sensor and one monitor.
Diy garage door monitor.
The doorbell switch now activates the garage door opener and the light comes on when the door opens whole thing runs off the existing door bell transformer using repurposed 4 conductor telephone corded.
The build cost 05 and only took an afternoon to complete.
Another reader stefan sent us entry that accomplishes the same tasks using an android app and an arduino controlled sensor.
These are reasonably inexpensive and easy to install.
The magnet is on the door.
Uses ifttt to update a google sheet when the status of the door changes.
Magnetic reed switches located on the garage door rails to monitor door open and closed.
Of course that all depends on whether or not you have a server a fair amount of coding skills and a few spare parts lying around.
The sensor is mounted in the garage according to manufacturer instructions.
We have had a few posts about monitoring your garage door but this one is a little bit different.
Communicate with thinger io to send when the door opened closed auto closed or the module rebooted.