He hooked up a TMP421-based temperature module along with a TEMT6000 ambient light sensor to his Arduino, which displays the data on a small LCD screen he purchased.

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 Arduino compatible Pax Instruments T400 Temperature Datalogger is now available to purchase priced at $175 from Adafruit. If you liked this you might also be interested in building an Arduino ...