The annoying thing about commercial smart home gear is its lack of interoperability. HomeAssistant is very flexible though, and it’s easy to use all kinds of gear—even stuff you bodge together yourself. [Jeff Sandberg] demonstrates that ably with his project to use ancient 1990s burglar alarm sensors in his modern smarthome setup.
The sensors in question are from an old GM Interlogix security system. The sensors themselves sit on doors or windows. They use magnets and a reed switch to sense if the door or window is opened. If so, they send out a radio message saying as much. All [Jeff] had to do was catch those messages and translate them for HomeAssistant.
To listen in on the sensors, [Jeff] employed a Nooelec NESDR—a software defined radio that could pick up the 319.5 MHz signals. The NESDR runs a tool called RTL_433, which can decode the sensor signals, and spit out MQTT messages to interface with HomeAssistant.
Much of the hard work was done already for [Jeff]—he just had to lace together the components. This is just a testament to the hard work by people in the HomeAssistant and SDR communities for figuring all this out and putting the tools online.
We’ve seen some neat HomeAssistant builds before, like this neat home control terminal. If you’re cooking up your own smarthome hacks, don’t hesitate to let us know!
Hooking up an old (obsolete?) burglar alarm to Home Assistant, cool!
I’ve seen a few homes with unused control panels on a wall. It would be neat to get them working again.
“old” is not 319.5 MHz, it’s wired.
Or maybe 27Mhz or 49MHz.
Message ends.
Maybe so, but wired is way more secure. It’s so easy for burglars to jam 319MHz and 2.4GHz while doing the dirty….
Old is not 319.5MHz.
It’s wired.
And then later, maybe, 27MHz or 49MHz.
Message repeats.
There are actually products that are designed to integrate existing panel based systems into HomeAssistant. I don’t remember which ones, as they weren’t relevant to me, but I’ve seen people mention them in various other online discussions.
Unfortunately all the control panels and such were ripped out before I purchased this house, which is why I had to wind up doing radio (Original blogpost author)
Konnected is the one I’ve been thinking about buying.
I reverse engineered the 1-wire protocol of my house alarm and connected it to Home Assistant with an ESP8266. fun project and it works great
Didn’t know General Motors made alarm systems. Always thought those were General Electric when I worked on them. Learn something new every day.
It’s GE. The article writer was wrong.
Do you know wireless door lock system with energy harvesting and no 2-year lifetime li-ion battery (or worse, Li batteries?)
Konnected.io has a get product that uses existing wired security sensors and integrated very well with Home Assistant.
Some of the Nooelecs can be unreliable. I have a NESDR Nano 2 which appears to have cooked itself to death – all it was doing was sitting in my util room connected to a Pi, recording data from my meters.
I used the konnected device to reuse my existing wired alarm sensors and replace my old alarm panel when it died. Integrates nicely with Home Assistant. Konnected.io