Rotary Encoder For Dummies : For Arduino, Raspberry Pi

Some theory better to know before buying rotary encoders. Here is rotary encoder for dummies guide intended for Arduino, Raspberry Pi users. Rotary encoders are like potentiometers but potentiometers do not have full rotation without limits unlike encoders. Rotary encoders output reflected binary code (RBC) (also known as Gray code) to inform how much, in which direction the encoder has been turned. Rotary encoder is a very big topic in electrical engineering and electronics. They have extensive industrial usage. But this guide is intended for the development boards like Arduino, Raspberry Pi or PIC or Atmel microcontrollers. Amount of theory mixed practical needed to know for correct purchase is basic.

Rotary Encoder For Dummies : Basic Theory

There are different types of rotary encoders like rotary encoders without push button action. This type costs very less, hardly $2 per piece. Their usage is for things like volume control knob, control of servo motor etc.

Rotary encoders with push button action should be your choice for general works. These type of rotary encoders’ shaft rotates and the same shaft can be pressed to use as a pushbutton. Different rotational torque varies from model to model. Their usage is for things like with a display where we need a select action too. If you use rotary encoders without push button action for the purpose, you will need a separate push button.

There are other types of rotary encoders with different features, some has integrated joystick. Commonly, rotary encoders require 5V DC supply, usually uses an internal LED and optical detector to produce the output. Of course build quality among the rotary encoders depends on the manufacturers.

Some companies build rotary encoders with funky features. You possibly should select a rotary encoder with encoders with push button from a good manufacturer. Minimum cost of this type of units can go around $3 per piece.

Rotary encoders without push button action costs very less as we mentioned above. Rotary encoders with push button action on one side will have a 3 pin connector including ground and two coding pins and the other side will have two pins for switch.

Rotary encoders need a knob, which is usually not included. These knobs are called potentiometer knobs. They are sold as lots online, you can buy one piece from local electrical equipment shop.

Rotary encoders can be mounted on PCB – breakout or sold as piece. Obviously rotary encoders with push button as breakout with knob is practical for using with breadboard.