Rotary Encoder

A rotary encoder is a turnable dial that outputs its direction. A rotary encoder is very different from a potentiometer in that it reports its actual location via a digital signal, such as I2C rather than just reporting resistance.

Rotary encoders can also be turned continuously without stop unlike most pots who often have less than a 360° turn.

Note that where a potentiometer's location accuracy is mainly dependent on the microcontroller's ADC, a rotary encoder will be rated in steps or pulses. A 12 step encoder has 12 distinct places the switch can be rotated to, so it is limited to those 12 spots.

Types

 * Optical Rotary Encoder - Uses an optical sensor to read the location
 * Magnetic Rotary Encoder - Often just looks a typical IC, it reads the rotation of a magnet the is placed above (but not touching) it.