I have a USB fan attached to my Raspberry PI. The pi runs 24/7 and is standing right next to my bed together with the USB fan.
The USB fan has only one on / off switch and no other fan speed controls. But I just want a little breeze and no wind channel near my bed, because otherwise I wake up from the fan noises (the fan is very loud and the blades are rotating very fast)
I think lowering the USB voltage at one of the 2 USB interfaces should be right. How can I do that? Is there any other option for controlling the fan speed with my PI?