Here is a simple, yet useful circuit of an Arduino 4-digit 7-segment LED display unit. The module used here is a self-contained, compact common-cathode module containing four 7-segment LED numeric ...

We set the potentiometer pin as 0 (A0 on the Arduino Uno board), the CONTROL variable is the voltage that is used to cotrol the led brightness of the speed of the fan. In the setup() function the ...