Cheap Modules Upgrade Home Security System

[gw0udm] had an ancient monitored alarm system fitted to their home, and decided it was time to upgrade to something a little more modern. They chose a system from Texecom, but when it came time to hook it up to their computer, they were alarmed at the costs – £40 for what amounted to a USB-to-Serial cable! There were other overpriced modules too. But [gw0udm] wanted to upgrade, so it was time to hack the system.

The first step was grabbing a £4 USB-to-Serial board and wiring it up – a simple job for the skilled hacker.  As we always say – everything speaks serial. [gw0udm] then set their sights higher – they wanted the Ethernet interface but weren’t about to cough up the coin. After some research, it was determined that a Raspberry Pi could be used with a utility called ser2net with the existing serial interface to do pretty much the same job. It was a simple matter of figuring out the parity and messaging format to get things up and running.

From there, the project moves on to tackling the creation of a GSM module for monitoring in the absence of a local network, and on flashing the firmware of the system itself. It’s great to see a project continually grow and expand the functionality of a product over time.

We see a lot of security systems here at Hackaday – high prices and proprietary hardware tend to inspire the hacker spirit. Check out this reverse engineering of an obsolete 1980s system, resplendent with Eurostile font.

6 thoughts on “Cheap Modules Upgrade Home Security System

  1. A really nice series of posts. I have the same alarm (brand), and have also been looking for a way to integrate it with my network. My efforts (such as they are) have been around the idea of a small wireless interface, such as an ESP8266 or RTL8710 providing a single UART for the panel to communicate with, running a UART-TCP forwarder like esp-link.
    Things that have held me back have been powering it from the 12V supplied by the panel, as well as level conversion (and obviously, tuits that are sufficiently circular!).

    Alternatives I have thought of include a small Linux SBC such as the Onion2 and such like, level convertors, and dual UARTs that would allow simultaneous operation of both the GSM and Wintex software. (I was unaware that it was possible to add even MORE UARTs to the alarm panel!) My approach to allowing online alarm monitoring, as well as Wintex configuration would have been to simply kill or suspend the monitor software whenever an inbound TCP connection arrived on port 10001.

    Using a small SBC with multiple UARTs, and the GSM module attached to that would also allow for a home control system to make use of the GSM modem for things like notifying the owner that their primary internet connection has gone down, etc, rather than it having to be dedicated to the alarm system. When connected via USB, most modems offer multiple tty’s which can be used to interact with the modem core. One of those tty’s could be connected to a physical UART on the SBC using something like socat (e.g. socat /dev/ttyUSB3 /dev/ttyS1)

    Alternatively, a modem emulator (Hayes command set interpreter) could be used to accept “SMSes”, and relay them as instant messages or emails via the home wifi.

    1. So, while I had it workign using an Orange Pi Zero for a few years, eventually the Ethernet port packed in, and I was back to square one.
      This time I implemented an Ethernet to UART interface using an ESP32, a level converter, and a couple of pin headers. It’s still powered by USB, until I can lay hands on a K7805. It’s running ESPHome, and a custom StreamServer that I found conveniently implemented by someone else :-)

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