I'm building an Arduino alarm system. I want to add some wireless sensors, both motion and alarm contact (door) sensors. There are lots of alarm hardware options, does anyone have any recommendations for a place to start? Does anyone have any suggestions for a wireless system that's easy to integrate with an Arduino?
I was really hoping to get wireless sensors for $10 or $15, and just have those transmit to some wireless receiver that can feed my Arduino. I was thinking something like this: http://www.smarthome.com/7311D/Skylink-WD-318-Household-Alert-Door-Window-Alert-System/p.aspx