Everything is OK alarm

This device is a clever watchdog for your home, it monitors doors, water and temperature in the basement, the sensors have wireless interface so no need to trace cables, the main unit is connected to the phone line for remote access. It’s not just a simple alarm system, beside that it monitors the acces points, it also checks the temperature in the basement, to prevent in case of low temperatures the water in the pipes can freeze and crack the pipes.

The brain is the MC9S08GT micro controller from Freescale, so it is harder to replicate, but you can find usefull solutions in the documentation for your future projects, maybe redesign the entire system for your favorite ATMEL or PIC micro controller.

Everything is OK alarm:[PDF][Download]