Making your own security system isn't too hard, but if you'd like a super cheap and simple method, Instructables user deba168 shows how to make a wireless motion detector with an Arduino.

Real Time Home Security System using GSM Technology-An Anti-theft System! This project deals with the design & development of a theft control system for home, which is being used to prevent/control ...

He’s using an Arduino Uno and an Ethernet breakout board to hook it up to the network. This allows him to send text messages to himself when the alarm system is armed, disarmed, or triggered.

He figured that monitoring the alarm’s LEDs would make the most sense, so he used a bit of Ethernet cable and wired all of the system’s indicators to his Arduino board.

Basic DIY home security systems start at about $225 and top out at $800 or so. If you add wireless smoke/heat detectors, plan to spend about $1,300 for DIY alarm systems.

If you want to make your own system for doing so, Instructables user ICStation shows off how to use an Arduino to do it. The system here monitors temperature, humidity, and smoke levels and alerts ...

Luckily, Arduino’s own cloud services make it surprisingly easy to code for the Oplà. I opened the box, plugged the board into the Carrier, and then connected the board to my computer.