BrewMonitor
An Arduino-powered, cloud-based homebrewing controller for 17 euros.
My buddy Martin built an Arduino-powered brewing monitor and I helped out. An Arduino clone, an ESP8266 WiFi module, and a DS18B20 temperature sensor, total cost about 17 euros. It talks to a cloud API so you can monitor your fermentation from anywhere.
Born out of The Bedroom Laboratory, the whole point was proving you don’t need to spend 200 quid on a fancy controller when a few cheap components and a weekend will do.