I, like many Tindarians, love the Raspberry Pi. What I don’t like is letting it get too hot, and I find it annoying to simply leave a fan on all the time. After all, when embedded, these devices often only really do something every once in a while, so why waste wear and tear on a fan, as well as power, that other 99% of the time?
One solution is a passive heat sink, which is my preferred method in many situations. But when I found I needed to actively blow air over the processor using a fan, I didn’t find an easily available solution. So I made this one! The EZ Fan Raspberry Pi Fan Control PCB brings together a resistor, transistor, and diode (conspicuously missing in the image above), along with header pins into which you can plug your fan and the Pi. This allows it to source power from the 5V rail, and be controlled with a 3.3V IO pin.
While it’s a simple enough gadget to make yourself with a bit of soldering, this device makes things a matter of plug-and-play when you select the fully assembled option. It’s also available as a bare PCB, or as a parts kit, or even with connector wires. Finally, if you’re wondering how to actually turn it on based on temperature, the documentation includes a script for automating this task, though it only checks the status once per minute.