CH340-fan-control is a python script to control a USB fan with the QinHeng Electronics CH340 and HL340 USB relay module under Linux.
It will turn a USB powered fan on when a given temp is exceeded (the default is 80 degrees C) and turn it off when it falls below a lower threshold value, defaulting to 70 degrees C.
I own a few Android TV boxes that have poor thermal designs that are prone to overheating when under sustained load. This can either cause your device to significantly slow down or even shut down entirely. This can be fixed by cutting a hole in the bottom on your TV box above the SoC and sticking a small USB fan over it. In my case I am using a AC Infinity 40mm x 20mm USB Fan that cost me £10.
Fans can be annoying if they're always on so you can use this script in conjunction with a QinHeng Electronics CH340/HL340 based USB relay module, mine cost me £5, to only activate the fan when it is required. My CH340 is badged as a SONGLE but I've seen similar devices badged as Mogzank or HALJIA 5V USB relay modules or controllers.
Connect the grey (or red) wire from the fan into the COM (middle) terminal of the relay module and connect the grey (or red) wire of the USB header to the NO terminal of the relay. No soldering is required, it is usually enough to screw the wires into the terminals. The black wire should remain unbroken.
Whilst I have been successful in connecting and powrering a USB hub, my relay and a fan all from a single USB port on my X96 Air Q1000 whilst keeping the CPU temp below 85 degrees under full load, you will get better results if you give the fan a dedicated USB port.
These scripts require Python 3 and the Python USB modules. You will very likely have Python 3 installed already. To install the python USB modules run:
$ sudo apt install python-usb
Under Ubuntu and Debian based distros, or:
# pacman -S python-pyusb
Under Arch and Manjaro.
You can manually start and stop your fan using CH340-interactive.py:
$ sudo ./CH340-interactive.py -on
Installing CH340-fan-control.py involves a few more steps.
Copy CH340-fan-control.py into /usr/local/bin and copy CH340-fan-control.service into /etc/systemd/system and make sure they're executable:
$ git clone https://github.com/danboid/CH340-fan-control.git
$ cd CH340-fan-control
$ sudo cp CH340-fan-control.py /usr/local/bin
$ sudo cp CH340-fan-control.service /etc/systemd/system
$ sudo chmod u+x /etc/systemd/system/CH340-fan-control.service
$ sudo chmod u+x /usr/local/bin/CH340-fan-control.py
Start the service:
$ sudo systemctl start CH340-fan-control
Enable it to run at boot:
$ sudo systemctl enable CH340-fan-control
Note that you cannot use CH340-interactive.py whilst the CH340-fan-control service is running. You must stop the CH340-fan-control service first before you can use CH340-interactive.py.