Raspberry PI Fan control

This script keeps your SBC healthy by regularly checking CPU temperature and running an externally attached fan when necessary.

Installation

$ apt install python3 python3-pip

Run ./install.sh. This installs Python requirements and copies fanctrl to /usr/bin/.

$ ./install.sh

Optional

By running ./install_systemd.sh, fanctrl is installed as systemd service fanctrl.service under lib/systemd/system/ to run after each system start. Log is written to /var/log/fanctrl.txt.

$ ./install_systemd.sh

Usage

When installed for running after system start, there is no need to run fanctrl manually as temperature checks and fan spinning is performed automatically.

To manually run the fan, call fanctrl -f:

# Run the fan, no matter the actual cpu temperature
$ fanctrl -f

Get more information with fanctrl -h:

usage: fanctrl.py [-h] [-f [FORCE]] [-i [INTERVAL]] [-t [TEMPERATURE]]
                  [-p [PIN]] [-l [LOG]]

optional arguments:
  -h, --help            show this help message and exit
  -f [FORCE], --force [FORCE]
                        Force fan on for FORCE time (default: 15s), no matter
                        the temperature, and quit. Program does not enter
                        scheduling mode.
  -i [INTERVAL], --interval [INTERVAL]
                        Interval in which cpu temperature is checked. Min:
                        10s, Default: 30s
  -t [TEMPERATURE], --temperature [TEMPERATURE]
                        Temperature (in °C) at which the cooling function is
                        triggered. Default: 48°C
  -p [PIN], --pin [PIN]
                        Physical pin which triggers the fan (BCM mode).
                        Default: 17
  -l [LOG], --log [LOG]
                        The log file temperature changes are written to.
                        Called once per interval.

Default values

• Default fan pin: 17 (BCM mode)
• Default temperature trigger: 48°C
• Default interval: 30 seconds
• Default fan timer in force mode: 15 seconds