Getting Connected With Your Home Security System

This simple device, paired with some creating code will let you become your own home security monitoring service. It’s called the PhantomLink and [Adam] started the project as a commercial venture. He recently decided to go open source with the hardware and will soon be posting a guide on how to program your own web interface too.

We just looked in on a project which takes control of a security panel using an Arduino. The PhantomLink is focused on not just reusing the input hardware, but monitoring the whole system. It sounds like several different protocols are supported.

The DB9 jack is intended for use with an adapter you can wire yourself. Basically just tap into the terminal block on the alarm controller for your house, then route those connections to the proper pins. A PIC 12F683 monitors the alarm system, pushing data via the WiFi module mounted on the board. With that web connection you can do anything you want by catching and formatting the data.

24 thoughts on “Getting Connected With Your Home Security System

  1. Excellent project. I did something similar by tying my existing Ademco alarm into home automation system by using an
    AD2USB device:

    Now when my alarm is tripped, I can receive an SMS message and having the wireless motion sensors and door sensors’ data available to the home automation system is beneficial for occupancy sensing. I wrote a wrapper program around the alarm data feed so that different events can trigger different scripts based on time, frequency of events, etc. This works well for feeding the HA system. For example front door sensor constantly flags an error on the
    alarm panel as all sensors do, and every couple of minutes my HA system will speak “Front door left open” rather than every few seconds.

    Before buying the AD2USB device, I also had sampled the siren (sounder) output to determine when the alarm was tripped. The system I have, which is an older Vista 10se periodically polls the sounder to make sure it’s still there and will generate an error, apparently to thwart a criminal cutting the wire. I remember having to “debounce” this input as a result.

    Anyway I am interested in open-sourcing my project as well and am looking
    for collaborators.

  2. Oh come on! sensing 12v on the sounder?
    here was me thinking he was interfacing on the protocol level.

    What’s next, connecting batteries to coils and moving nails by magic??

    1. So far I’ve only released the most basic implementation of the firmware. The common denominator among most panels, regardless of manufacturer, is the presence of a siren output, which is why this approach was used for version 1. But please note that a microcontroller was strategically placed between the input lines and the Wi-Fi module to provide a path forward for implementing protocol-level communication. There are a couple of different techniques I’m experimenting with to make this work, but they currently require different firmware loads for different panel protocols. As soon as I get the details sorted out, I’ll be posting updates to the firmware.

    2. This reply seems unnecessarily discourteous. Everyone here is trying to be helpful and inventive, and some people are by definition less knowledgeable than others (but probably more helpful and less arrogant).

  3. I designed one once around a z80 and POTS kits. I did sensors on some doors and windows, and most importantly motion/heat detection units in some ceiling corners. Also a gel cell 12v for backup power.

    I never could find a response service to dial out to for the POTS though..

    1. PWM..

      There is no packet protocols on any of the ones I’ve come across. I’ve also messed with ADTs residential and commercial units. They are simple PWM streams except for industrial systems that connect to mainframes, but they don’t get high sales on those. Those usually go to security contractors who wire into PWM multiplexers that then go to a mainframe.

    2. I put a logic analyzer on the control panel interface of an FBII alarm panel and was able to get data packets off it. There are 4 wires, two are power and ground for the control panel and the other two are open colector (pulled up to 12V) TX and RX. It’s just ASCII, but I haven’t decoded the packet format yet.

      The control panel displays alarm and system status messages, so it looks like a very viable way of getting panel status, and can also be used to arm or disarm the panel by sending packets corresponding to keyboard presses. Much easier than building a modem to interface to the phone line.

      My plan is to use an Arduino serial port to interface to the control panel serial lines and and Ethernet shield to create a web interface.

      One of these days I will get a round tuit…

      1. That’s essentially what the AD2USB device does. It makes all the data you see on the panel available at a USB port so you can parse through it, and you can also inject key presses onto the bus. I had to blank out both the POTS phone numbers that the panel was trying to call to get rid of the phone line error message.
        I have a friend who did reverse-engineer the POTS side for his ademco alarm and made his own device for connecting to its POTS line. It provides dial tone to the alarm, answers and interprets all the alarm data and makes it available on a serial port to his BSD box. I almost went this route until I realized that I wanted to use the motion and door sensor data as inputs to my home automation system. It’s nice to hear the system speak “Hey you, you left the gate open again!”

  4. “That’s essentially what the AD2USB device does”

    Sure wish they made it for my panel…it would save me a lot of work. I have emailed them to ask if it’s possible, but I doubt they will be interested.

    Anyway, the fun is in reverse-engineering the comm protocol and spoofing a keypad.

    1. Hi ka1axy,

      It looks like you have beat me to it. I was planning on doing the same thing, but came across your posts. I have FBII as well, were you able to decode it? If not, could the messages just be replayed or do they use some kind of random salting?



  5. I appreciate all of the interest in this project. I finally have the gerber files for the PCB posted. I’ve also been receiving a lot of questions about how the WiFly module works and how it is programmed. The configuration utility software provides a wizard that does everything automatically, but I added a terminal window to give a bit more low-level visibility and control into the process. I’ve also been working on a tutorial webpage ( to help demonstrate some of the other features of the WiFly module since the board can be used as a generic XBee/RN-XV breakout board too if you remove the microcontroller.

  6. This is very interesting. I have a friend who wants to have his doorway set up with a motion sensor that sets up a picture. He also wants the “doorbell” switch to set up a call to him on his phone so that he can answer through the speaker. Has anyone seen anything like that or have any ideas?

    1. The project files for the Wi-Fi version were taken down due to some legal concerns. The current Ethernet based version is much simpler and uses a basic Lantronix Xport for most of the core functionality. Schematics are posted on the PhantomLink website for those who want to build it.

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