The AS-1 is a fully-featured home security system built on the Arduino platform. It includes all the standard features you would find in a commercial system, plus some unique ones that alarm installers and homeowners may find useful. This is not one of those gimmicky highly simple security system in a box things that they sell on TV; this is much more like what a professional would install in your house.
The prior work available on this subject was limited mainly to tutorials on how to build single-room alarm systems out of Arduino boards. A few webpages dance around the possibility of making a system like this, but none that I could find actually have explicit instructions on how to do it.
For the most part, the project went according to plan (except that I had to do it solo because everyone else either got recruited by other groups or wanted to do something radically different than what I wanted). A few things had to be cut due to time constraints (most notably the keypad housing, as seen in the photo above). But other than that, it worked out quite well.