Home Made Alarm Systems?

screwBrinks! asks: "I would like to begin a new project to do during those long and boring weekends. I thought about creating an alarm system in my apartment which would be connected to my computer. Then, if there is any intrusion, it would page me or phone me. I also want to be able to see a live report from the web and some other goodies. I have no problem doing the software part, but I don't have much experience with building hardware. Have any of you ever built such a system? If so, what would be your recommendation? I know much of this may already exist prebuilt, but I really would like to make as much of it as I can, for fun. I have no problem against using prebuilt infrared detectors, prebuilt door contacts, and the like as long as they aren't X-10 products."

Comments

Homemade Security devices

[p7]

I haven't done it before, but I imagine you could make most of the items out of stuff from Radio Shack. Door contacts could be two small (can't remember the name, but they are the scall strong magnets) magnets with opposing poles to puch up on a microswitch. Then you need an optical tripwire which you could possibly set up using a photovoltaic sensor and an laser led. That would cover the doors and windows. If you can reasonably cover the windows with the light beam device you shouldn't need motion detectors. Then if you get any voltage drop or an open you set off the alarm.

Re:I've seen this done

[NorthDude]

Yep! CCD camera are very impressive at "seeing" IR. In fact, digital camera needs special filter to block out near visible IR light because they would ruin a photo. But using special purpose IR filter (which blocks visible light), you are still able to make some incredibly good IR shots.

GNU Phantom.Security

[Yottabyte84]

I found this a while ago. This connects to your printer port and supports 5 zones. The electronic hardware is quite easy to build (I've built simmalar things). You could also modify it to provide home automation.