In November last year — I started building a DIY security alarm system, using a Raspberry Pi as the controller. My plan was to make a self-sustained system, using proper alarm hardware — like PIR sensors and sirens.

Integration with Home Assistant would be an add-on, not a requirement. I wanted the system to be as redundant and fault-tolerant as I could make it.

This is a pretty long story, with some twists and turns — let’s get into it 👇

Using a few cheap sensors, a wireless keypad, Zigbee2MQTT and Home Assistant; I was able to get a basic security alarm up and running during a free afternoon 🙂

Keypad with programmable PIN code, two outputs (modes) and protection against repeated incorrect PINs. Uses an AVR ATtiny2313 microcontroller.