RaspFanControl

A script to automatically control a raspberry fan with the CPU temperature.

Completly written in bash. No libraries and/or extra packages needed.

It works by setting a pin high when the CPU temperature raises above a certain level, and setting it low when it is below that same level.
That means that it works to drive directly the fan by connecting it to the pin, or you can also connect a transistor to the pin to use as a switch and drive the fan with 5V instead.

Added a new version where there are two temperature thresholds, one for turning on the fan and one for turning it off (this threshold is a lower temperature then the top threshold). This change was made because with one single threshold it was constantly turning on and off the fan.

The old version can still be found in the repository under the name fan-control-old.sh.

Configuration

The temperature threshold, pin nunber and time between checks can be changed in the fan-control.sh script.

Install

You can launch this script at startup your preferred way, but also, included with the actual script is a systemd service. To use it place the fan-control.service inside the /etc/systemd/system directory and the fan-control.sh inside /usr/local/bin (you can change where you place the fan-control.sh, just make sure to specify it inside the fan-control.service file).

Then run systemctl start fan-control.service to start the script and systemctl enable fan-control.service to automatically start it at boot. If you reboot you should see the service as active if you run systemctl status fan-control.service.

Keep in mind that you need to run this script as root user or it will fail. The way I specified above does that.