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.

Call it synchronicity, or manually setting a 16-bit number in an Arduino, or how to turn an OLED into a rotary dial ...

The device itself consists of an off-the-shelf ultrasonic sensor, an Arduino, and a digital potentiometer. It all fits in a custom 3D printed enclosure and runs of two rechargeable coin cells.

Deep in the bowels of the Digikey and Mouser databases, you’ll find the coolest component ever. Motorized linear potentiometers are a rare, exotic, and just plain neat input device most commo… ...