This repo is mostly based on Aerandir14's work with a few changes to suit my needs.
Also the repo aggregate stuff together so I won't get lost next time building one.
Tested on Raspberry Pi 4 running Raspbian busty.
For parts and building instruction, please refer to the original post.
Modify the pin on GPIO and PWM frequency.
$ python calib_fan.pyApply the same pin and frequency to fan_ctrl.py, then
$ python fan_ctrl.py &If you want to run the script whenever system start up, put it in rc.local/cron job. Or, even better, running as a service
$ sudo cp fan-ctrl.service /lib/systemd/system/
$ sudo systemctl enable fan-ctrl.service
$ sudo systemctl start fan-ctrl.service