Originally I was thinking about building a motion detecting sensor system from scratch for the Adafruit Make it Tweet contest, but after thinking about what I would need to assemble to build it I figured there must be an easier solution. I started looking around for pre-built home security sensors etc... when I stumbled upon the GE Choice-Alert Wireless alarm system. I figured why not let it do all the heavy lifting of monitoring the sensors then I only need to figure out a way to make it tweet. Since the LEDs indicate the status of the sensors and alerts all I really needed was a way to monitor them and then send the results to Twitter.
If this sounds interesting keep reading to find out how to build one yourself. Before we get started lets go over the material we will need:
1 x GE 45142 Choice-Alert Wireless Control Center with Door or Window Sensor Kit from Amazon, Lowes or Home Depot ($30 -$40) - Comes with a single magnetic sensor for doors/windows many other sensors can be added ($15-$25 each)
1 x Arduino UNO from Adafruit ($30)
1 x Arduino Ethernet Shield from Adafruit ($45)
1 x 9V regulated DC wall-power adapter from Adafruit ($7)
1 x Arduino Project Enclosure from Sparkfun ($12)
1 x Right Angle Male Header strip from Sparkfun ($2)
Length of Cat 5 cable
Heat shrink tubing
Step 1: Open the Control Center case
We are interested in the LED leads protruding from the bottom of the circuit board.