This project is a modular alarm system. It uses an arduino MKR1000 in every unit, which is mounted on the standard board. To this board, you can connect multiple other boards with different sensors or relays.
The idea is that you can choose which kind of sensors you want to protect your house. For example, you want smoke detectors, but you also want burglar sensors on the same system.
Every standard board with the MKR1000 will also have a buzzer on it, so the central computer (raspberry pi) can alarm every one at home if there is a fire or something like that. You can also use a buzzer from 1 station to alarm only 1 place. For example, when there are burglars at night and you are sleeping, only the buzzer in your room could go of, to wake you up.
You can also make your own expansion boards with your own sensors on it. The 5 pin connector gives you access to an interrupt or an analog pin and I2C pins.
Every module would connect to your home network and send it's data to a raspberry pi, which handles the alerts etc.
This is my project, I hope you like it and I hope I have time to work it out further.