I have been using the Fan Shim for my RPi 4 (Raspbian Buster 4.19) for over a month now and it really is a game changer for my CPU-intensive tasks. I am using the automatic script to toggle the fan on and off, and it seems so be working fine (except for the button which wouldn’t on/off in automatic mode, but whatever).
I noticed that the fan speed is different between the different fan toggles. Sometimes it would spin at full speed which is quite noisy and sometimes it would spin “normally” and make 0 noise. I have been wandering in the code of FanShim repo but couldn’t find anything that explains it.
Could somebody explain why does it turn at different speeds? And if it is possible to set only one?