pifan

This project includes a daemon and a client, that provide precise control over a fan that is attached to one of the PWM outputs of a Raspberry Pi. With a single configuration file, you can set high and low temperatures, use different control profiles for your fan, or control things like frequency used to drive the fan. This program is built on top of gpiozero, which is a Python library available on Raspberry Pi.

Installation & usage

Currently the daemon can be installed by cloning the repository and using the provided setup.py-file. Steps are provided below.

1. Get the source code: Clone the repository by running git clone https://github.com/ekelhala/pifan.git
2. Install: Move to the cloned repository: cd pifan, and run sudo python setup.py install (you might need to install setuptools with sudo apt install python3-setuptools). This will build and copy all necessary files to right locations.
3. Set up the systemd service: We want to run this daemon in the background, so we'll use a systemd service to achieve this. Run sudo systemctl enable pifan to enable the service at startup, and sudo systemctl start pifan to start the service now. If you have everything set up correctly, your PWM fan connected to Pi's GPIO 12 should start spinning at full speed.
4. Configure the daemon: If you want to change how the fan behaves, you should edit the file /etc/pifan/default.toml (for example with nano: sudo nano /etc/pifan/default.toml). After making your changes, remember to run sudo systemctl restart pifan to restart the fan service, which also reloads the configuration file you just edited.

pifanctl

After installation, you can use the command-line client to communicate with the daemon. Use sudo pifanctl <command> to run the client (check commands below).

Commands

Currently pifanctl offers the following commands:

• status
  • See the status of the daemon, including fan speed and system temperature
• config
  • Inspect the configuration of the daemon
• set_controller <controller>
  • Set the fan controller profile. Possible values for controller are: max_speed, linear_interpolator and silent. Check controllers for more information.

Configuration

not added yet

Controllers

pifan provides the following controller profiles for your fan: max_speed, linear_interpolator, silent, and stepwise. The controller you want to use can be selected by setting the value of controller under [fan] in the configuration file. Default controller is max_speed.

max_speed and linear_interpolator

The max_speed-controller drives the fan at full speed all times, while linear_interpolator looks at the current temperature, and increases the speed of the fan linearly when the temperature increases. When using linear_interpolator, the fan is turned off, when the current temperature goes below the low temperature (set with temp_low). When high temperature (temp_high in configuration) is reached, linear_interpolator drives the fan at maximum speed.

Adding new controllers

The structure of the code is designed in a way which makes adding new controllers easy. You can add your controller code under fan_control by following the structure of existing controllers, and using the BaseController and ControllerOptions to operate the controller. After writing your controller, you can make it available through get_controller, and a configuration option, which you can set in the configuration file.