cpufan.py

#!/usr/bin/env python3
# Author: Edoardo Paolo Scalafiotti <edoardo849@gmail.com>
# Use with a PNP transistor like the P2222A
# Add line in /etc/rc.local to execute file on boot.

import os
from time import sleep
import RPi.GPIO as GPIO

pin = 15 # The pin ID, edit here to change it
maxTMP = 45 # The maximum temperature in Celsius after which we trigger the fan


def setup():
    GPIO.setmode(GPIO.BCM)
    GPIO.setup(pin, GPIO.OUT)
    GPIO.setwarnings(False)
    return()


def getCPUtemperature():
    res = os.popen('vcgencmd measure_temp').readline()
    temp =(res.replace("temp=","").replace("'C\n",""))
    #print("temp is {0}".format(temp)) #Uncomment here for testing
    return temp


def fanON():
    setPin(True)
    return()


def fanOFF():
    setPin(False)
    return()


def getTEMP():
    CPU_temp = float(getCPUtemperature())
    if CPU_temp>maxTMP:
        fanON()
    else:
        fanOFF()
    return()


def setPin(mode): # A little redundant function but useful if you want to add logging
    GPIO.output(pin, mode)
    return()


try:
    setup()
    while True:
        getTEMP()
        sleep(10)  # Read the temperature every 10 sec, increase or decrease this limit if you want
except KeyboardInterrupt: # trap a CTRL+C keyboard interrupt
    GPIO.cleanup() # resets all GPIO ports used by this program