Control a PWM Fan on a Raspberry Pi

Tested on Raspberry Pi 3B+ and 4B but should work on other versions as well.

Installation

• Connect PWM capable Fan to GND, 5V and GPIO 12 (Pin 32)
• Copy or link RPiFanControl.service to /etc/systemd/system/RPiFanControl.service
  • sudo ln -s $PWD/RPiFanControl.service /etc/systemd/system/RPiFanControl.service
• Copy or link RPiFanControl.py to /usr/local/bin/RPiFanControl.py
  • sudo ln -s $PWD/RPiFanControl.py /usr/local/bin/RPiFanControl.py
• Optional: Copy RPiFanControl.example.ini to /etc/RPiFanControl.ini and edit the config
  • sudo cp RPiFanControl.example.ini /etc/RPiFanControl.ini
  • sudo nano /etc/RPiFanControl.ini
• Install python requirements
  • Run sudo pip3 install -r requirements.txt
• Enable system service
  • Run sudo systemctl enable RPiFanControl
• Add dtoverlay=pwm-2chan,pin=12,func=4,pin2=13,func2=4 to /boot/config.txt and
• Reboot your Pi

Usage

Once the script is running it will control the connected fan according to the settings.
See comments in RPiFanControl.py for details.

It will by default also update two files with the current values on each change:

• /run/RPiFanControl/temperature contains the current CPU temperature in °C as a float
• /run/RPiFanControl/dutycycle contains the current PWM duty cycle in % as an integer