The project illustrates the control of a PC fan speed and using an Arduino microcontroller to read a LM35 temperature sensor. The use of an optocoupler is covered along with Pulse Width Modulation ...

I have heard it said that PWM fans are controllable by software. I understand the PWM connectors are the 4-pin But speedfan was around pre PWM wasn't it? So for 3 pin fan connectors. Could it control ...