Glass Break Detector for Ring Alarm System

A little while ago, we installed a Ring alarm system in our house. We like it quite a bit. The initial installation hurdle was the need for three range extenders; then, two motion detectors were unreliable, but that turned out to be a battery issue. For the last month or so, it has run without a hitch.

Price was one of the main reasons to go with Ring instead of SimpliSafe. Both the equipment and the professional monitoring was cheaper (monitoring is $10/month or $100/year for Ring, compared to at least $15/month with SimpliSafe). Compared to ADT and Brinks, we didn’t want a long-term contract.

One thing that had me pause for a few days before purchasing the Ring system was the lack of a glass break detector. It’s really surprising that Ring doesn’t have one. In the end, though, I convinced myself that it’s really not a big issue. There are two situations: either we’re home and the system is armed, or we’re not home and the system is armed. If we’re not home, then the motion detectors are armed, and anyone stepping into our house will be detected. If we are home, then the system is armed in such a way that the motion detectors are disabled, but I’m pretty sure we’d hear the sound of glass breaking.

Still, this bugged me a little. I ended up buying another Ring contact sensor, the same little sensors we’re using on all our doors and windows. I opened it up, and it has a little magnetic reed switch in it. If I don’t use the magnet, and instead use a couple of wires to bypass the reed switch, I can simulate opening and closing the contact switch by disconnecting or connecting the wires, respectively.

There are third-party glass break detectors, for example the Honeywell IntelliSense FG-1625. It has a “normally closed” connection, which is exactly what I need: Normally, I want the wires connected, thereby bypassing the (always open) reed switch. If breaking glass is detected, I want the wires to be disconnected.

I wired up both the Ring contact sensor and the Honeywell glass break sensor accordingly, but unfortunately, the Ring wouldn’t register the glass break sensor opening the connection. In the end, I added a 2k Ohm resistor as an end-of-line resistor from C (“closed”) to EOL (“end-of-line”), and now it appears to work. When nothing is happening, Ring shows the contact sensor as closed. When the glass break sensor detects breaking glass, Ring shows the contact sensor as open, and I can alarm on it.

I’m trying this out, for now, without actually alarming and possibly calling the cops over. I’m looking for two things:

  1. Are there false positives? I’ve got the combined sensor sitting in our living room, where the most action happens. But unless we actually break glass, I shouldn’t see an alarm.
  2. What’s the battery life for the glass break sensor? It’s not really meant to be run on a 9 V battery. If the battery drains too quickly (which would register as “open connection” and therefore “glass break”, unfortunately), I probably have to hard-wire it. See update below.

Update: A day in, and the battery has drained sufficiently that it’s not outputting 9 V anymore, but only about 6.4 V. That was enough for the glass break detector to go offline (and show as “open” in Ring). I’ve now hardwired it to a 9 V power supply, and am continuing to test item #1 above.


About Mathias

Software development engineer. Principal developer of DrJava. Recent Ph.D. graduate from the Department of Computer Science at Rice University.
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