Making my old dumb alarm smart


(Chris) #1

I’m working on a project to remote control and monitor my “ancient” home alarm system using ST. It’s a late 90’s Ademco FA110C system, designed to dial out on a hard line. No remote control capabilities (except for a hardwired physical keyswitch arm/disarm option), no web or smart capabilities. I priced out replacing it with a Vista 20P system…the panel itself is relatively cheap, but after adding 3 keypads to replace the current 3 in the house, and getting an Envisalink to complete the communication piece, I’d be looking at around $400 to go this route.

I think I have figured out how to arm and disarm remotely using a GoControl relay module to simulate the alarm’s keyswitch option. I also think I can use an external-input-capable contact sensor with a 12v relay to send a signal if the siren activates. Simple enough, and probably looking at a cost of $60-70 instead of $400.

I’d like to take things one step further and find a way to turn each of the 6 zones into ST devices so I can see the state of each zone, and also possibly measure frequencies of a signal across a couple terminals to determine if the alarm is Armed/Ready/Not Ready. Is there a single device out there that can do something like this? I could add 6 separate contact sensors, but then I’m starting to get closer to the cost of replacing the whole thing, which pretty much defeats the purpose.


(Chris) #2

Did a little more digging. Zone notification isn’t going to be worth it. I realized I can get armed/disarmed status from one of the keypad LEDs using a 12v relay. Will be ordering a contact sensor to report on relay state. It’ll be basic, but with one GoControl relay and one contact sensor I’ll be able to remotely arm and disarm the alarm, and see armed/disarmed status. Good enough for me.


(Amauri Viguera) #3

There is another thread around that has some details on how to connect the contacts to a Raspberry Pi via the GPIO ports. I actually ordered the breakout board and everything for mine but it just arrived and haven’t had a chance to take a stab at it, but it might be worth a try.


(Chris) #4

I just realized that the power input for the control board is 16VAC, not 120VAC, so I can’t power the GoControl relay module from the panel like I thought I would be able to. There’s no other power source close to my panel and I’m not willing to run new wiring for an old alarm system. I think I’ll be better off replacing the whole system with a Vista 20P and Envisalink. If I only get one keypad instead of 3 I can do it for a little over $200, and have full control over arming/disarming, state monitoring (armed away vs armed stay), and individual zone monitoring. One other nice thing about upgrading is that my current FA110C panel only has 6 zones, so two of my entry doors are combined into one zone, and the third entry door is combined with some window sensors. Since the 20P has 8 zones, I can split each of these doors out into it’s own zone, and use those zone statuses to monitor door state instead of the Iris contact sensors I’m currently using.


ADT unknown model and smartthings integration
(Chris) #5

So I ended up figuring it out. The AC adapter for the panel actually had two twisted pairs in it. I separated them and used 2 wires for power and the other two to act as jumpers to pull the terminals used for the keyswitch back out to where the AC adapter is plugged in. I was then able to hook up the relay switch in the same box as the AC adapter.

Here’s the inside of the panel. The terminals with the red and green wires are the ones that are connected to the relay switch. I duplicated the LED function of the keyswitch as well so I can see alarm state (armed/disarmed ready/disarmed not ready) from the panel. Not that it’s worth much.

Here’s the contact sensor by one of the keypads. There’s a 12v automotive relay that I had laying around inside the panel, triggered by the red Armed LED light. When the LED is on, the relay closes, which also closes the reed switch in the contact sensor, making it show Closed instead of Open.

I modified the standard z-wave door/window DTH to show armed/disarmed instead of open/closed and changed the associated colors as well.

The dual Alarm status things (one is the contact sensor, one is a virtual switch) is necessary to sync status and allow arming and disarming from both ST and manually from the keypad. I can also use Alexa or GH to verbally turn the Alarm System switch on/off.

Set up some automations as well with CoRE, and I now have a basic smart alarm system for about $65. I was able to add the Alarm System switch to my routines to arm/disarm automatically. Also set up a couple of pistons to act like a quasi-self monitoring system. May eventually get another contact sensor to tell if the alarm siren is activated, but for now I can infer if the siren is active by looking for doors opening and then no change in the alarm state within 30 seconds after.


(tony) #6

This is something that I have been trying to figure out for some time now! I ordered everything I need so we’ll see if it works for me…

Thanks for the great idea here! … Only thing I’m going to have trouble with is changing the open / closed to armed / disarmed… Can you tell me where you found the code and how to modify the code?

I’m very new to Smartthings and I don’t fully understand github yet…

Thx … Tony