Intruder Alarm

Intruder Alarm

Central to my whole plan for automating the house is a decent burglar alarm. Clearly there are benefits in having an alarm for it’s own sake. Several of the houses on our street have now got alarms, so I figure that makes our house slightly more appealing to your casual house breaker.

I’ve done a very considerable amount of research about which alarm system to go with. I think I’ve read the sales blurb, and installation manuals for pretty much all the major panels available in the UK. Ranging from Scantronic i-ON, Visonic Powermax, Texecom Premier, through to the Cooper Security Menvier. The house developers offered us an alarm as a £600 upgrade when we bought the house, you get three wireless PIRs and one wireless door contact, which wouldn’t come close to meeting my needs. Also, I want to be able to tinker. So I need to know everything I can about the system.

I’ve ended up settling on the DSC Power Series. This was for three main reasons. They offer a brilliant ‘disappearing’ wireless door/window contact. It’s only about five millimetres thick, and so will slip easily between the door or window and the frame. This not only has aesthetic advantages, but it also means an intruder has no idea where sensors might me placed (or indeed, not placed). Secondly, there are pretty comprehensive integration modules that allow the panel to be connected to a computer or IP network. There are also a couple of third party boards that improve on this even further. For my purposes this is a major consideration. I want the panel to feed me details of pretty much all the events that occur on the system, PIRs being tripped, doors opening or closing or wires being cut.

The third reason was that I read somewhere that the DSC panels are incredibly complex and offer very detailed, fine-grained programming options. And as such, only experienced professional installers should tackle it. That sounds like my kind of system.

So my plan is to augment the alarm panel with an Envisalink 2DS, which connects to the IP network, and reports all events on the system. It also allows commands to be executed remotely. But I’m not sure how wise that would be, it seems like a potential serious vulnerability. This sounds like an ideal task for the Raspberry Pi, I might try writing my own daemon that listens for the updates from the panel and then shove them in a mySQL database.

In addition to this I’m planning to use the programmable outputs on the panel, connected to an Arduino to provide broad-scale information about the system, such as whether it’s armed, in alarm, tampered, or if the sensors on the each of the three floors have been tripped.

Hopefully using some combination of these two data streams, I should be able to provide pretty reliable occupancy detection, in order to switch off lights on floors that aren’t in use, and of course switch on the ground floor lights when anyone returns home (at night obviously).

So I’m currently filling and re-filling my shopping cart on the vendor’s website, deciding exactly which bits I need…