CS P5 I0 Configure 5th digital pin for input without pull-up resistor. DG P5 Get the digital value of 5th digital pin. CE P9 OP Configure 9th digital pin for PWM output and store the configuration in ...

Arduino Uno; 3- or 4-pin PC fan [optional] Potentiometer (e.g., this one) If you only have a 3-pin fan, be aware that your fan will always run at maximum speed. Additionally, if you do not opt for ...