[Mikey Sklar] finds himself in need of a temperature regulated refrigerator for fermenting foods like yogurt, kimchi, bread, and beer. After some testing he found that by building his own controller he can get a chest freezer to outperform an upright refrigerator at this task by 2-to-1.
The controller is based around an ATmega48. It includes a remote temperature sensors which you can see connected to the lower left header in the image above. On the back of the board there’s a relay used to switch the freezer’s power on and off. [Mikey] is selling a kit but the hardware and software for the project are both open source so build it yourself if you have the know-how.
A chest freezer is a great place to store Cornelius kegs… we’ll keep our eyes open for one.