Monday, September 2, 2013

Rotary Encoder Interfacing With MSP430 LaunchPad

       This a a follow up to the Roatary Encoder with PIC micro in this demo we will use Texas Instrument MSP430G2211 with MSP430 LaunchPad 

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

Schematic with MSP430G2211

Source code and firmware

CLIK Here To download Source Code and Firmware. 

if you have any problem please leave in the comment section.


  1. Hello, I need the same circuit with 12F675.. Any Idea? Thank you

  2. HI, I need the same circuit with TM4C TIVA microcontroller.