The device is essentially an RFID temperature sensor snuck inside a custom-made magnetic stir bar. The bar is paired with a smart hotplate base that displays the temperature readings.

I used an LCD shield to display the current temperature and speed of the fan, but you can use the circuit without the LCD display. You also need to select the transistor by the type of fan that you ...

The hardware follows a straightforward formula, aside from Arduino and display it boasts an Adafruit sensor board and a hardware clock.