I bought a new house last Summer and, of course, the first thing I did was start automating things! My house came with an ADT security system installed, but not active. I have no interest in using the control panel or professional monitoring, but I figured there should be a way to use the sensors that came with the house. Specifically, I have Honeywell/Ademco contact sensors/motion detector from the early 2000’s which operate on 345 MHz.
It turns out that these devices use a proprietary wireless protocol, but that was only a bump in the road. After much hacking, researching, and experimenting, I have integrated these sensors with ST by way of a raspberry pi with an SDR dongle listening to the sensors. It’s not 100% reliable due to SNR issues, but its plenty good to use the sensors for some typical automation (turn on lights when the door opens, etc). It’s especially satisfying that I got six contact sensors and one motion detector for ~$60 ($35 for the RPi, $25 for the SDR dongle).
I think this approach could be especially interesting to anyone who would like to keep their ADT panel active, monitored, and un-tinkered-with. Nothing has to change with respect to the ADT hardware, since it just listens to the existing signals.
SO, I have some code for the RPi, a smart app, and a couple of device handlers, which I’d be happy to share. I just wanted to test the waters and see if anyone is interested in trying this for themselves before I go to the work of documenting and publishing my project.