fan_ctrl_opi.py

fan_ctrl_opi.py

#!/usr/bin/python
# -*- coding: utf-8 -*-
 
# For Orange Pi
# Tested on Orange Pi Plus 2

import OPi.GPIO as GPIO
import time
import sys
 
# Configuration
FAN_PIN = 21  # Chip pin used to drive transistor's base
WAIT_TIME = 1  # [s] Time to wait between each refresh
FAN_MIN = 20  # [%] Fan minimum speed.
PWM_FREQ = 25  # [Hz] Change this value if fan has strange behavior

# Configurable temperature and fan speed steps
tempSteps = [50, 70]  # [°C]
speedSteps = [0, 100]  # [%]
 
# Fan speed will change only of the difference of temperature is higher than hysteresis
hyst = 1
 
# Setup GPIO pin
GPIO.setboard(GPIO.PLUS2E)
GPIO.setmode(GPIO.BOARD)
GPIO.setup(FAN_PIN, GPIO.OUT, initial=GPIO.LOW)
fan = GPIO.PWM(FAN_PIN, PWM_FREQ)
fan.start(0);
 
i = 0
cpuTemp = 0
fanSpeed = 0
cpuTempOld = 0
fanSpeedOld = 0
 
# We must set a speed value for each temperature step
if len(speedSteps) != len(tempSteps):
    print("Numbers of temp steps and speed steps are different")
    exit(0)
 
try:
    while (1):
        # Read CPU temperature
        cpuTempFile = open("/sys/class/thermal/thermal_zone0/temp", "r")
        cpuTemp = float(cpuTempFile.read()) / 1000
        cpuTempFile.close()
 
        # Calculate desired fan speed
        if abs(cpuTemp - cpuTempOld > hyst):
            # Below first value, fan will run at min speed.
            if cpuTemp < tempSteps[0]:
                fanSpeed = speedSteps[0]
            # Above last value, fan will run at max speed
            elif cpuTemp >= tempSteps[len(tempSteps) - 1]:
                fanSpeed = speedSteps[len(tempSteps) - 1]
            # If temperature is between 2 steps, fan speed is calculated by linear interpolation
            else:
                for i in range(0, len(tempSteps) - 1):
                    if (cpuTemp >= tempSteps[i]) and (cpuTemp < tempSteps[i + 1]):
                        fanSpeed = round((speedSteps[i + 1] - speedSteps[i])
                                         / (tempSteps[i + 1] - tempSteps[i])
                                         * (cpuTemp - tempSteps[i])
                                         + speedSteps[i], 1)
 
            if fanSpeed != fanSpeedOld:
                if (fanSpeed != fanSpeedOld
                        and (fanSpeed >= FAN_MIN or fanSpeed == 0)):
                    fan.ChangeDutyCycle(fanSpeed)
                    fanSpeedOld = fanSpeed
            cpuTempOld = cpuTemp
 
        # Wait until next refresh
        time.sleep(WAIT_TIME)
 
 
# If a keyboard interrupt occurs (ctrl + c), the GPIO is set to 0 and the program exits.
except KeyboardInterrupt:
    print("Fan ctrl interrupted by keyboard")
    GPIO.cleanup()
    sys.exit()

Hello...I am sorry to bother you....but how does it work...I want to control POE module on my Rspberry Pi system. I installed ubuntu 22.04 server image on Raspberry Pi. I installed OPi.GPIO for ubuntu OS. Then I run your script but on my machine it gives error
"python3 fan_control.py
Traceback (most recent call last):
File "/home/ubuntu/fan_control.py", line 27, in
fan = GPIO.PWM(FAN_PIN, PWM_FREQ)
TypeError: PWM.init() missing 2 required positional arguments: 'frequency' and 'duty_cycle_percent'
".

Your help will be valuable to me.

Thank you.

Hello...I am sorry to bother you....but how does it work...I want to control POE module on my Rspberry Pi system. I installed ubuntu 22.04 server image on Raspberry Pi. I installed OPi.GPIO for ubuntu OS. Then I run your script but on my machine it gives error "python3 fan_control.py Traceback (most recent call last): File "/home/ubuntu/fan_control.py", line 27, in fan = GPIO.PWM(FAN_PIN, PWM_FREQ) TypeError: PWM.init() missing 2 required positional arguments: 'frequency' and 'duty_cycle_percent' ".

Your help will be valuable to me.

Thank you.

This is for Orange Pi, Not a Raspberry Pi.
so you need find other script.

Thank you so much for your reply. I modify your code with "import RPi.GPIO as GPIO "and it's executing fine on my system. The only issue is that I don't find any details for how to check its performance....I am very new in this area so trying to find out details online.
In code I set tempSteps = [50, 70, 80, 90, 100], speedSteps = [0, 20, 30, 40, 100] but couldn't see any changes in fan speed.

I am sorry for taking so much of your precious time. Can you please let me know how to verify performance?

Thank you & Regards,
Yashashree

Thank you so much for your reply. I modify your code with "import RPi.GPIO as GPIO "and it's executing fine on my system. The only issue is that I don't find any details for how to check its performance....I am very new in this area so trying to find out details online. In code I set tempSteps = [50, 70, 80, 90, 100], speedSteps = [0, 20, 30, 40, 100] but couldn't see any changes in fan speed.

I am sorry for taking so much of your precious time. Can you please let me know how to verify performance?

Thank you & Regards, Yashashree

Maybe your fan device not compatible to this script.

Basically I just following this post but I make an changes to match OPi. So you need DIY control board.

And this source are control Fan speed by CPU tempurature.
I don't know your environment, but firstly you need choose correct tempurature sensor (CPU, or something...) and it's maximum tempurature.