Domen Ipavec shares his temperature alarm for boiling milk in the project log forum:
Anyone who has ever boiled milk on the stove knows, that it has a nasty habit of overflowing. That is why I created the temperature alarm for boiling milk to be used my mother.
The temperature alarm uses attiny841 microcontroller and DS18B20 to continuously measure the temperature of the milk and sounds an alarm when the temperature is over the preset alarm value.
I’ve designed the pcb in KiCAD, etched the pcb at home and soldered it together.
The case is made from 4mm plywood and the buttons are small pieces of wooden rod glued to a square piece of plywood so they can not fall out.
Project info at Domen Ipavec’s blog.