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

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.

I’ve wanted to use an ESP8266 WiFi module in a project for some time now, and after reading about the WeMos board, I figured this was the easiest way to get started. The WeMos D1 mini is quite small and much easier to interact with and program than the ESP8266 devices. So I built this single relay controller, with internal temperature reporting. I am communicating with it using MQTT, which makes it really easy to implement it into things like Home Assistant.