fanctrl is a utilty for the Raspberry Pi 4B to control a PWM fan's speed based on the current CPU temperature.
By default, fanctrl uses GPIO pin 18 to set the speed of the fan. It turns the fan off entirely as long as the CPU temperature is below 60 degrees Celsius and linearly increases it until the CPU temperature reaches 80 degrees Celsius, at which point the fan will run at full power. The fan speed is adjusted every 5 seconds. These defaults can be changed by modifying the values in fanctrl.cpp.
To start, run fanctrl as root. For the first 5 seconds the fan will run at full speed so that you can ensure it is working properly. fanctrl also provides a systemd service to make it easier to use (see the installation section further down).
- WiringPi 2.52 or newer (see "Updating WiringPi" below)
- CMake 3.7 or newer
- Working C++ compiler that supports C++11
Use
cmake -DCMAKE_BUILD_TYPE=Release -Bbuild -H.
cmake --build build
sudo cmake --build build --target install
to install fanctrl and the systemd service. If you want to start fanctrl automatically during boot, additionally call
systemctl enable fanctrl
and to start it immediately use
systemctl start fanctrl
If you don't want to install the systemd service for some reason, pass -DINSTALL_SYSTEMD_SERVICE=OFF to the first cmake invocation.
As of right now (Oct 3rd, 2019) raspbian does not ship WiringPi 2.52 yet. To update, use
wget https://project-downloads.drogon.net/wiringpi-latest.deb
sudo dpkg -i wiringpi-latest.deb