So like many people I have a Security System already wired into my house. Door sensors, window sensors, Motion detectors, etc.
When we moved in I played around with it and figure out the code to use it; but never had any intention of hooking it up to ADT or any of the other security companies.
As I’ve been getting deeper and deeper into HA, it’s always bothered me that I couldnt figure out a way to utilize those existing sensors in my SmartThings environment. Why buy new wireless motions, door sensors etc, when I already have a great setup of wired ones in place?!
When browsing around for solutions, I noticed that many of the Z-wave door sensors have an external sensor port; where you can wire an external sensor into the Z-Wave sensor.
My logic was, why not just use this external port to send the status of my wired sensors.
So I ordered a Z-wave door sensor from Monoprice, and tried it tonight. After some playing around, I’ve got my wired sensors sending a status to the Z-Wave door sensor, which then updates the hub.
Step 1: Add wires to the external sensor port of your Z-Wave door sensor
Step 2: Connect wires “before” the diode to the hardwired sensor you want to connect to (before the diode means on the sensor side, not the panel side) This is important, in testing it did not work when I clipped my leads to the “panel side” of the wires, I am not an electrician, engineer, or have much (any) electronics background, but apparently the diode is necessary to isolate the sensor
Step 3: Test it.
You can see in the pictures below the wiring diagram for my security system, the alligator clip leads to the z-wave sensor clipped onto the hardwired sensor wires, and the z-wave door switch sitting on top of my alarm box.
Now I just have to use a smart app to notify me when there is a status change, motion, etc when there shouldn’t be.
You will be limited by the “zones” on your security system, and will need a door sensor for each zone; but there have been good deals on 4packs lately for these