The Temperature Candle is a relatively simple design which essentially boils down to a 8-pin microcontroller, a temperature sensor and voltage reference and a RGB LED on a 1.5″ diameter PCB – the same size as a standard votive candle. The micro flickers the LED like a candle at a color determined by the ambient temperature. The color gives an indication of the room temperature in reference to the recommended sleep time temperature for
babies to reduce the risk of SIDS (Sudden Infant Death Syndrome).
The candle can also blink the temperature by pressing a reset button on the PCB.
This should be a relatively cheap kit and it uses all thru-hole components so it should be easy to assemble. Using a simple micro, it can also be a good introduction to microcontrollers, and is designed with a jack to connect to Microchip’s Pickit 3 programmer / debugger.
You can see more information and look at all the design files on its project page.
The Temperature Candle - [Link]