Cooling Fan Control Raspberry Pi Libreelec.

Quote from RolandP

Hi,

coming back to the 4-wire fan with PWM:

I just connected the blue wire (pwm control wire) to GPIO18 (pin 12), set in the cooler.py script: GPIO.PWM(12, 25000) 12 for the pin and frequency to 25kHz and here we go: works like a charm -so far.

Thanks for your help.

Cheers

Roland

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You can set GPIO and Frequence variables here

# Configuration
FAN_PIN = 18  # BCM pin used to drive transistor's base
WAIT_TIME = 10  # [s] Time to wait between each refresh
FAN_MIN = 30  # [%] Fan minimum speed.
PWM_FREQ = 25000  # [Hz] 25kHz for Noctua PWM control

and leave this as is

fan = GPIO.PWM(FAN_PIN, PWM_FREQ)

You can also play with the temp and speed you need...

# Configurable temperature and fan speed steps
tempSteps = [30, 40, 45, 50, 55, 60, 65, 70, 75]  # [°C]
speedSteps = [0, 30, 35, 40, 60, 70, 80, 90, 100]  # [%]

this is what I m using

My fan only starts at 30% so anything lower then that it won't start

This is a small tool to change speed from SSH for testing before you set lowest speed in script..It lets you input different speed from SSH till your fan starts..

calibrate.py.txt

Quote from Nayed

I have a great request:

Can you sum up 1 working solutions with all the steps needed in your first post as the topic is interesting but it is going longer and longer.

The topic is growing and in 1 part we have scripts, update in another, after there is script with variable speed and for me it is a bit confusing

Thanks in advance!

What are you planning to do?

2 pin 5v fan ?

Script in post #60 works fine for PWM temp/speed control..

You just need to make circuit..

Quote from Nayed

2 pin 5v fan

I made a circuit with 2n2222 transistor and 1k resistor I use the following circuit

Temperature Controlled Fan for Raspberry Pi 4 - Fizzy

but I would like to use your script from #60 because of the speed control

I just change the fan file from the link above with your script from #60 and now intend to turn it on

Seems I made something wrong(either circuit, either places for the script, .. or something else) as I turn it on but the fans are not starting

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Did you connect transistor base to the proper gpio?

Quote from Nayed

How can I verify that the speed fan is temperature controlled? I am looking at it and speed seems the same all the time

Post #74 I posted a small script calibrate.py

That is similar script to the one on #60 but works manually from terminal instead of reading temperatures...it's just for testing and to find your fan minimum speed...mine started at 30%...less then that and it wont turn...

You can test fan with that script from terminal....you type 50 will be 50% speed..100 will be 100% speed and so on...

Quote from Nayed

Thank you!

---

speed steps in script are low so you dont see much difference by looking at the fan

tempSteps = [30, 35, 40, 45, 50, 55, 60, 65, 70, 75]  # [°C]
speedSteps = [0, 35, 45, 50, 55, 60, 70, 80, 90, 100]  # [%]

try to change the steps and you ll see a big jump from 50% to 100%

something like:

tempSteps = [45, 50]  # [°C]
speedSteps = [50, 100]  # [%]

This way it jumps from 50% straight to full throttle

You just edit script and restart to try with 50% to 100% but you dont really have to..if fan is working all should be fine

If you want to try change values just ssh systemctl reload fan.service or stop and then start service