To do so you can use a cooling fan with PWM (Pulse Width Modulation) support. The official raspberry pi fan has PWM support. It has 3 pins: red: +5V black: GND blue: PWM The official raspberry fan ...

The 3.3V microcontroller used here requires a logic level shifter to boost the PWM signal up to 5V for the fan. I use the 74AHCT125 to perform the logic level conversion, using pin #40, VBUS, to ...

Of course, the standard way of controlling CPU fans these days is with PWM, so he built a circuit which essentially converts the PWM signal from the motherboard into a phantom thermistor.

For our safety-critical system, we are using the TMS570LC43 to generate a PWM with the N2HET module. All worked well until we saw that the N2HET pin max voltage dropped from 3.3V to 2.1V. So, I build ...

Based on settings I can get the PWM output to be either off 100% or on 100%, and my fan reacts accordingly, so I don't believe there is any issue between the pin and the fan (i.e. not likely a HW ...