An open source home alarm monitoring system using Raspberry Pi, Netduino Plus 1 and ATtiny85.
This code contains information related to typical home alarm systems. Please, be aware that this procedure may void any warranty. Any alarm system of any type may be compromised deliberately or may fail to operate as expected for a variety of reasons. The author, G. García, is not liable for any System Failures such as: inadequate installation, criminal knowledge, access by intruders, power failure, failure of replaceable batteries, compromise of Radio Frequency (Wireless) devices, system users, smoke detectors, motion detectors, warning devices (sirens, bells, horns), telephone lines, insufficient time, component failure, inadequate testing, security and insurance (property or life insurance).
http://homealarmpluspi.blogspot.com/2013/04/blog-post.html
Original work started with just Netduino Plus 1. Then ATtiny85 and Raspberry PI. The following link shows the original implementation. http://netduinoexperience.blogspot.com/