Rotary Encoder Interfacing with PIC Mirocontroller

       i am currently working with some power supply design and i can say using conventional pots(potentiometer)  and rotary  switch  to adjust the voltage and other stuff is quite old school. so i have decided to go for a bit high tech , actually bit digital.

so here is the solution

Incremental Rotary Encoder

first of all i would like to tell you , these type of rotary encoder is totally digital component so you can't directly replace these  with you conventional pots. so lets start what are Incremental Rotary Encoder , Incremental rotary encoders by the looks of it just like a general purpose pot looks like but output is quite different they  provide a pair of digital signals that allow a microcontroller to determine the direction of a shaft’s rotation. They can be used to monitor motors and mechanisms, or to provide a control-knob user interface.

   for a quick look here is a typical incremental rotary encoder

and hear the output wave form

Decoding with Microcontroller 

in this examples we will be decoding the rotary encoder with the help of sate machine.

view of state machine in the wave form