⚠️ NOTE: This project is currently in early stages of development and can change rapidly. Expect breakage between releases.

The Hwmon Handheld Fan Controller (hhfc)

This is meant to be a universal controller for anything that can be read and writen from hwmon sysfs filesystem. Originally designed for handhelds but can be configured for anything that has sensors and fans exposed via hwmon sysfs exclusively (i.e. /sys/class/hwmon/hwmon?/*)

Install

On ArchLinux (and derivatives) there is hhfc-git package in the AUR.

For installing from sources you'll need some python packages first:

• build
• installer
• wheel
• setuptools
• pyyaml

Then clone sources and build/install

$ git clone git+https://github.com/Samsagax/hhfc.git
$ cd hhfc
$ python -m build --wheel
# python -m installer dist/*.whl

For system daemon use copy the systemd unit:

# cp -v systemd/hhfc.service /usr/lib/systemd/system/hhfc.service

Usage

Run hhfc with a given configuration file:

$ hhfc -c fan_control.yaml

:info: You may need root privileges (i.e. sudo) to write to hwmon attribute files.

There are some examples under config directory in the repo. See Configuration for writing your own for your machine

Systemd unit (system daemon)

The most common usecase once configured is to run it as a system daemon. Write a configuration file for your machine and place it in /etc/hhfc/fan_control.yaml (create directories if appropriate). Then enable the systemd unit if not already. It will look for the system configuration and start the daemon:

# systemctl enable hhfc.service

Monitor mode

You can also run the controller in "monitor mode" by usign the -m flag. This way the controller won't write to fan handles but can monitor sensor readings and fan speeds.

# hhfc -m -c fan_control.yaml

Configuration

The driver uses FANS and SENSORS as the configuration units defined on a yaml file.

Defining sensors

Sensors are read from hwmon drivers given it's name and temperature input. Often the sensors need to be scaled and offset to have a readable value.

Example SENSORS section:

SENSORS:
  - name: "cpu"
    driver_name: "k10temp"
    temp_input: "temp1_input"
    divisor: 1000
    offset: 20
  - name: "gpu"
    driver_name: "amdgpu"
    temp_input: "temp1_input"
    divisor: 1000
    offset: 20

• name defines how the sensor will be referenced by fans
• driver_name is the name of the hwmon driver to watch (i.e. /sys/class/hwmon?/name attribute)
• temp_input name of the attribute file to read temperatures from.
• divisor the value to divide the read temp_input. This is an optional parameter, if not set it will default to 1000.
• offset the value to add to the read temp_input after the division. Most chips expose the temperature with an offset of 20°C. This parameter is optional and will default to 0 if not set.

Each sensor needs to be prepended with a list marker (i.e. -)

Defining fans

Any fan can watch one or more sensors. It needs at least one to function. Fans need to be defined by a name, the hwmon driver name and hwmon attribute to handle and read its input.

Example FANS section:

FANS:
  - name: "fan1"
    driver_name: "oxpec"
    handle: "pwm1"
    max_control_value: 255
    min_control_value: 0
    fan_input: "fan1_input"
    allow_shutoff: yes
    minimum_duty_cycle: 30
    sensors:
      - name: "cpu"
        curve: [
         [60, 0],
         [80, 50],
         [90, 100]
        ]
      - name: "gpu"
        curve: [
         [60, 0],
         [80, 50],
         [90, 100]
        ]

• name is the name to reference this fan.
• driver_name is the name of the hwmon driver to write to (i.e. /sys/class/hwmon?/name attribute)
• handle is the hwmon attribute file to write to (i.e. /sys/class/hwmon?/pwm1 in this case)
• max_control_value and min_control_value are the min and max value the controller will write to the handle. Duty cycles are defined and used in the [0-100] interval, written values will be mapped to [min-max] values before writting. This parameters are optional, if not set they will default to the range [0-255].
• fan_input is the hwmon attribute to read fan speed from.
• allow_shutoff determines if the fan is allowed to be shut off. The value should be "yes" or "no" (default). If the fan is allowed to shut off completely the value of minimum_duty_cycle will be used to turn it on and the lowest value in the fan curve will shut it off. If the value is "no", the value of minimum_duty_cycle will be used as the lowest value for the fan.
• sensors define a list of sensors and its curves this fan will monitor. Each sensor curve definition needs to start with a list marker.
  • name is the sensor name that will be matched from the SENSORS section
  • curve defines points with temperatures and corresponding duty cycles. The lowest and higher points will also work as cutoffs. Any temperature value reading below the lowest or higher than highest will be set to the corresponding duty cycle value. Duty cycle is on the range [0, 100].

Contributing

If you have written configurations for some device that can be generic enough and safe to use, please add it as a Gist link in this issue or as a Pull Request for inclusion.

The project is under the GPLv3 license and all kinds of contributions are welcome.