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 👇

My girlfriend wanted a digital calendar on the kitchen wall; I made one with a 24" monitor, a Raspberry Pi and DAKboard.

I’m using Prometheus to monitor my home office and homelab, I figured it would be cool to have a stack light show the active warnings and alerts from Alertmanager. So I made a HAT (Hardware Attached on Top) for the Raspberry Pi to drive a five-colored stack light.

I made a simple HAT (Hardware Attached on Top) for the Raspberry Pi to read multiple DS18B20 temperature sensors — it was surprisingly easy. I used the measured temperatures to control a fan using Home Assistant.