Quick recap: I’m building a DIY security alarm using a Raspberry Pi, hardwired PIR sensors, and MQTT integration with Home Assistant.

Hello again — it seems to be close to a year since I last managed to get some words published on this blog. And almost three years since I last wrote about my Raspberry Pi security alarm project 😮

But the project is still alive and well. We use it every night and whenever we are away, and it just works 😃 Development usually happens in bulk, with very little happening in between.

We have a Dakboard digital calendar in our kitchen — showing lots of house and temperature data. So naturally; it must show the actual outdoor temperature as well.

To do this I used a Raspberry Pi 2, and a DS18B20 HAT I made some years back.

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 👇

We recently got balanced ventilation installed, and I have interfaced it with Home Assistant. However — the ventilation unit have three “special modes” that can not be enabled through the Modbus interface; fireplace, kitchen, and override. These can only be set on the touch panel, mobile app, or through inputs terminals on the controller.

So I repurposed an old project and made a three-relay Wi-Fi controlled module, using MQTT to send commands and receive statuses.

Then used Home Assistant to automate it 🙂

As the weather is warming up here in Norway — my kids have gotten their bikes out. To make it more fun, both for them and me, I figured I’d build a series of traffic signals that they could play with.

I first started with a traffic light, simple — red, yellow and green. To control it I am using a Raspberry Pi Zero W, this will allow me to make it communicate on Wi-Fi and MQTT later.

My kids wanted traffic lights for their LEGO city, so first I had to build a traffic lights controller.

My twins and I both like LEGO, and LEDs. I figured I’d make some simple LED street lights that we could use to build a LEGO scenery.

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.

My twin boys are, like their dad, fascinated by switches and flashing lights. I needed an excuse to use the Raspberry Pi Zero in a project, so I built them a WiFi MQTT controlled alarm module. With a couple of switches, some panel indicators, a buzzer, and a blue LED strobe.