Py-RPi_PWM Controller

WARNING! This is an early development release, any use of this script is at your own risk!

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The project originally started off as a custom script for the NESPi-4 Fan Control PCB, but was later changed to be used with the official Raspberry Pi 4 Case Fan instead.

The script will not only turn the fan on/off, but also adjust the fan speed according to the temperature using a fan profile.

Installation

1. Go to the Getting started section on the official website and follow the first 5 steps except for the 4:th step where you should instead connect the cables like this:

   

2. Next install the fan controller python script:

   wget -qO- https://raw.githubusercontent.com/WaCrex/Py-RPi_PWM_Controller/master/install.sh | sudo bash -

Fan Profiles

The script comes with 3 fan profiles: silent, linear & cool. With linear being the default preset.

Configuration

The python script is by default looking for a json-file with the same name as the python script, by default this should be fan_ctrl.json.

/opt/fan_ctrl/fan_ctrl.json:

{
    "profile": "linear",
    "gpio_pin": 18,
    "pwm_freq": 100,
    "profiles": {
        "silent": [
            40, 40, 41, 41, 42, 42, 43, 44,
            45, 46, 47, 49, 51, 53, 55, 57,
            59, 61, 63, 65, 67, 70, 73, 76,
            79, 82, 86, 89, 93, 96, 100],
        "linear": [
            40, 42, 44, 46, 48, 50, 52, 54,
            56, 58, 60, 62, 64, 66, 68, 70,
            72, 74, 76, 78, 80, 82, 84, 86,
            88, 90, 92, 94, 96, 98, 100],
        "cool": [
            40, 44, 47, 51, 54, 58, 61, 64,
            67, 70, 73, 75, 77, 79, 81, 83,
            85, 87, 89, 91, 93, 94, 95, 96,
            97, 98, 98, 99, 99, 100, 100]
    }
}

Option	Default	Description
profile	linear	The name of the profile currently in use (must be listed under profiles).
gpio_pin	18	The GPIO Pin that the fan's PWM cable is connected to.
pwm_freq	100	The frequency of the PWM signal.
profiles		A dictionary of fan profiles, with Duty Cycle values (%) for the temperatures 50-80°C. The values must be between 0-100% and decimals aren't allowed.