This repository contains code to control a Noctua PWM fan with GPIO pins, based on the CPU and ambient temperatures.
GPIO Fan Control
Hardware
Using Noctua 5V PWM fan. Note that the circuit diagram Noctua provides as an example for driving the PWM fan is incorrect. It should be a standard CMOS inverter circuit.
Pinout for Orange Pi Plus 2 is here: https://www.meccanismocomplesso.org/en/a-look-back-at-the-orange-pi-plus-2-board/
Software
The code for Armbian uses pyGPIO, which is not available in pip. Install as follows:
sudo apt-get install python-dev
git clone https://github.com/chwe17/pyGPIO.git
cd pyGPIO
sudo python setup.py install
fan_curve_control.py controls the fan speed, and requires a config file setting:
- Which pin to use for the PWM signal
- The location of a database to log the temperatures and fan duty cycle
- The file containing the cpu temperature
The controller sets the fan speed to run at one of three possible speeds.
Monitoring
Also included is a dockerised flask web app to display a graph showing measured temperatures and the duty cycle of the fan. The docker-compose.yml file requires two variables to be set in a .env file:
- The secret key for the web app
- The location of the database with the temperature and duty cycle information
The secret key is passed to the flask app in the container as an environment variable.