Changes

This `read_fan_speed.py` python file depends on the third-party python library `Rpi.GPIO`. In the official Raspberry Pi OS and most third-party OS, this library is installed by default. If you run this file and get some errors, try to run the following command to install the Rpi.GPIOy library.

sudo apt-get install -y python3-smbus python3-rpi.gpio

==Other==

<code>pwm_fan_control.py</code> is no longer used, and are reserved here for research and use by python lovers only.