67 lines
1.9 KiB
Python
67 lines
1.9 KiB
Python
#!/usr/bin/python
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# -*- coding: utf-8 -*-
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import RPi.GPIO as GPIO
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import time
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import signal
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import sys
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import os
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# Configuration
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FAN_PIN = 18 # BCM pin used to drive PWM fan
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WAIT_TIME = 1 # [s] Time to wait between each refresh
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PWM_FREQ = 25000 # [Hz] 25kHz for Noctua PWM control
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# Configurable temperature and fan speed
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MIN_TEMP = 40
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MAX_TEMP = 70
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FAN_LOW = 40
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FAN_HIGH = 100
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FAN_OFF = 0
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FAN_MAX = 100
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# Get CPU's temperature
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def getCpuTemperature():
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res = os.popen('vcgencmd measure_temp').readline()
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temp =(res.replace("temp=","").replace("'C\n",""))
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#print("temp is {0}".format(temp)) # Uncomment for testing
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return temp
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# Set fan speed
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def setFanSpeed(speed):
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fan.start(speed)
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return()
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# Handle fan speed
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def handleFanSpeed():
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temp = float(getCpuTemperature())
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# Turn off the fan if temperature is below MIN_TEMP
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if temp < MIN_TEMP:
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setFanSpeed(FAN_OFF)
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#print("Fan OFF") # Uncomment for testing
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# Set fan speed to MAXIMUM if the temperature is above MAX_TEMP
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elif temp > MAX_TEMP:
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setFanSpeed(FAN_MAX)
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#print("Fan MAX") # Uncomment for testing
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# Caculate dynamic fan speed
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else:
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step = float(FAN_HIGH - FAN_LOW)/float(MAX_TEMP - MIN_TEMP)
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temp -= MIN_TEMP
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setFanSpeed(FAN_LOW + ( round(temp) * step ))
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#print(FAN_LOW + ( round(temp) * step )) # Uncomment for testing
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return ()
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try:
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# Setup GPIO pin
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GPIO.setwarnings(False)
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GPIO.setmode(GPIO.BCM)
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GPIO.setup(FAN_PIN, GPIO.OUT, initial=GPIO.LOW)
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fan = GPIO.PWM(FAN_PIN,PWM_FREQ)
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setFanSpeed(FAN_OFF)
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# Handle fan speed every WAIT_TIME sec
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while True:
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handleFanSpeed()
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time.sleep(WAIT_TIME)
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except KeyboardInterrupt: # trap a CTRL+C keyboard interrupt
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setFanSpeed(FAN_HIGH)
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#GPIO.cleanup() # resets all GPIO ports used by this function |