A potentiometer (or "pot") is an electrical device used to measure angular position. The user can therefore adjust the degree to which the potentiometer opposes electric current through it, simply by turning a shaft that is attached to the center of the potentiometer. As the resistance of the potentiometer changes, so does the voltage, which thus causes the potentiometer to act as a variable voltage divider. This varying voltage can be measured by the VEX microcontroller and is directly proportional to the angular position of the shaft connected to the center of the potentiometer. This allows you to obtain an analog measurement of an angular position. The VEX potentiometer is designed with a “D-hole” in the center, which should slide easily over the VEX square shafts. The potentiometer includes two arcs, each ½in from the center hole; these arcs exist to assist with mounting the potentiometer to the robot structure.
Note: Before you can use the potentiometer, you must reprogram your VEX microcontroller to read the varying voltage of the sensor on the corresponding port you are planning to connect to.
Figure 1. Potentiometer graphic displaying how to use arcs for mounting.