#!/usr/bin/env python
import RPi.GPIO as GPIO
import time
import os

GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)

IMPULS_PIN		= 23	#Pin, der zum Transistor fuehrt
SLEEP_TIME		= 30	#Alle wie viel Sekunden die Temperatur ueberprueft wird
MAX_CPU_TEMP	= 40	#Ab welcher CPU Temperatur der Luefter sich drehen soll
MAX_SENSOR_TEMP	= 30	#Ab welcher Temperatur im Gehaeuse der Luefter sich drehen soll
SENSOR_ID 		= ''	#ID des Sonsors, BITTE ANPASSEN, falls kein Sensor vorhanden leer lassen



def get_sensor_temperature():
	try:
		tempfile = open("/sys/bus/w1/devices/"+SENSOR_ID+"/w1_slave")
		text = tempfile.read()
		tempfile.close()
		temperature_data = text.split()[-1]
		temperature = float(temperature_data[2:])
		temperature = temperature / 1000
		return float(temperature)
	except:
		return 0

def get_cpu_temperature():
	temp = os.popen('vcgencmd measure_temp').readline()
	return float(temp.replace("temp=","").replace("'C\n",""))



def main():

	#Init
	GPIO.setup(IMPULS_PIN, GPIO.OUT)
	GPIO.output(IMPULS_PIN, False)

	while True:
		cpu_temp = get_cpu_temperature()
		sensor_temp = get_sensor_temperature()
		if cpu_temp >= MAX_CPU_TEMP or sensor_temp >= MAX_SENSOR_TEMP :
			GPIO.output(IMPULS_PIN, True)
		else:
			GPIO.output(IMPULS_PIN, False)

		#print "gemessene CPU Temperatur:" + str(cpu_temp)
		#print "gemessene Sensor Temperatur:" + str(sensor_temp)

		time.sleep(SLEEP_TIME)


if __name__ == '__main__':
    main()