POTENTIOMETER
A variable resistor with three pins. Two of the pins are connected to the ends of a fixed resistor. The middle pin is connected to a wiper that moves across the resistor. This divides the resistor into two parts. These components are often referred to as pots and are used to adjust the voltage in a circuit. The volume knob on a radio is an example of a pot. A potentiometer is a simple mechanical device that provides a varying amount of resistance when its shaft is turned. By passing voltage through a potentiometer and into an analog input on your board, it is possible to measure the amount of resistance produced by a potentiometer (or pot for short) as an analog value. When the shaft is turned all the way in one direction, there are 0 volts going to the pin, and the input value is 0. When the shaft is turned all the way in the opposite direction, there are 5 volts going to the pin and the input value is 1023. In between, analogRead() returns a number between 0 and