raspi-fan-control-installer.md

Raspberry PI Fan Controller

To install run:

curl -Ls "https://git.io/JU4cX" |bash -

raspi-fan-control-installer.sh

#!/bin/bash

curl -Ls "https://gist.githubusercontent.com/mattrude/a8666cf2e3035d3644a1def86e48eea6/raw/raspi-fan-control.py" -o /usr/local/bin/raspi-fan-control.py && \
curl -Ls "https://gist.githubusercontent.com/mattrude/a8666cf2e3035d3644a1def86e48eea6/raw/raspi-fan-control.service" -o /etc/systemd/system/raspi-fan-control.service && \
sudo systemctl enable raspi-fan-control.service && sudo systemctl start raspi-fan-control.service

raspi-fan-control.py

#!/usr/bin/env python3

import subprocess
import syslog
import time

from gpiozero import OutputDevice


ON_THRESHOLD = 64   # (degrees Celsius) Fan kicks on at this temperature.
OFF_THRESHOLD = 56  # (degress Celsius) Fan shuts off at this temperature.
SLEEP_INTERVAL = 5  # (seconds) How often we check the core temperature.
GPIO_PIN = 17       # Which GPIO pin you're using to control the fan.


def get_temp():
    output = subprocess.run(['vcgencmd', 'measure_temp'], capture_output=True)
    temp_str = output.stdout.decode()
    try:
        return float(temp_str.split('=')[1].split('\'')[0])
    except (IndexError, ValueError):
        raise RuntimeError('Could not parse temperature output.')


if __name__ == '__main__':
    # Validate the on and off thresholds
    if OFF_THRESHOLD >= ON_THRESHOLD:
        raise RuntimeError('OFF_THRESHOLD must be less than ON_THRESHOLD')

    fan = OutputDevice(GPIO_PIN)

    while True:
        temp = get_temp()

        # Start the fan if the temperature has reached the limit and the fan
        # isn't already running.
        # note: `fan.value` returns 1 for "on" and 0 for "off"
        if temp > ON_THRESHOLD and not fan.value:
            fan.on()
            syslog.syslog("Case fan turned ON,  current cpu temperature is: %0.0f c " % temp)

        # Stop the fan if the fan is running and the temperature has dropped
        # to 10 degrees below the limit.
        elif fan.value and temp < OFF_THRESHOLD:
            fan.off()
            syslog.syslog("Case fan turned OFF, current cpu temperature is: %0.0f c " % temp)

        time.sleep(SLEEP_INTERVAL)

raspi-fan-control.service

[Unit]
Description=Raspberry Pi Fan Controller
StartLimitIntervalSec=0

[Service]
Type=simple
ExecStart=/usr/bin/python3 /usr/local/bin/raspi-fan-control.py
Restart=always
RestartSec=1

[Install]
WantedBy=multi-user.target