Everyone who has operated a stereo or radio is familiar with the volume control. Besides the tuning knob, this is probably the most used control. The technical name for it is the potentiometer. Because of its lengthy name, it is often referred to simply as the pot.
Because of the hardware access that the Raspberry Pi provides through its GPIO, I2C, and SPI ports, the potentiometer is potentially very useful. This chapter will explore its application.
Figure 7-1 illustrates a small collection of single-turn potentiometer types. Two old knobs for the shafted pot types are ...