Raspberry Pi 5 Auto Fan Controller

readme.md

Raspberry Pi 5 Auto Fan Controller

UPDATE: The fan is now controlled automatically in the latest updates (See this answer https://askubuntu.com/a/1497778/1746852). This cron job is no longer needed.

A quick hack to get around the fact Ubuntu for the Pi5 currently does not control the fan.

This needs to be run with sudo permissions:

sudo python3 pi5_fan_controller.py

And, by default, will monitor the Pi5's temperature for one minute every 2 seconds adjusting the fan based on some arbitrary boundaries I came up with on the spot :^)

This is intended to be set up as a system-wide cron job (system-wide because of the sudo privileges). To do this, edit this file:

sudo nano /etc/crontab

And add this cron job:

* * * * *  root  python3 /path/to/pi5_fan_controller.py

(with the updated path to the python file)

Many thanks to the following Ask Ubuntu answers:

• https://askubuntu.com/a/15834
• https://askubuntu.com/a/1491768

pi5_fan_controller.py

from enum import Enum
import time

TEMP_PATH = "/sys/devices/virtual/thermal/thermal_zone0/temp"
FAN_PATH = "/sys/class/thermal/cooling_device0/cur_state"


class FanSpeed(Enum):
    OFF = 0
    LOW = 1
    MEDIUM = 2
    HIGH = 3
    FULL = 4


def main():
    start = time.time()
    while time.time() - start < 59:
        temp = get_temp()
        if temp > 70:
            speed = FanSpeed.FULL
        elif temp > 65:
            speed = FanSpeed.HIGH
        elif temp > 60:
            speed = FanSpeed.MEDIUM
        elif temp > 50:
            speed = FanSpeed.LOW
        else:
            speed = FanSpeed.OFF
        set_fan_speed(speed)
        time.sleep(2)

        
def get_temp() -> int:
    with open(TEMP_PATH, "r") as f:
        data = f.read()
    return int(data) // 1000


def set_fan_speed(speed: FanSpeed):
    with open(FAN_PATH, "w") as f:
        f.write(str(speed.value))


if __name__ == "__main__":
    main()

Hi, I took your code, made it a little more oop, and wrapped a systemd service around it along with a simple bash script to set it all up.
https://github.com/nicciniamh/pi5-fan-control