Decoding Quadrature Signals using AT90CAN128
Akhilesh Gannavarapu1, Vatte Suresh2

1Gannavarapu Akhilesh, Electrical and Electronic Engineering, JNTU-H, Hyderabad, India.
2Vatte Suresh, Electrical and Electronic Engineering, JNTU-H, Hyderabad, India.

Manuscript received on May 01, 2012. | Revised Manuscript received on May 29, 2012. | Manuscript Published on June 10, 2012. | PP: 20-23 | Volume-1 Issue-1, June 2012. | Retrieval Number: A109051112/2012©BEIESP
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Abstract: A code is written for decoding the quadrature signals from the rotary encoder, to get a pulse train along with direction signal, which shows one transition period, and the direction of the rotation, whether in clockwise or anti clockwise directions respectively. It is especially important for machines in Industries which have to monitor the transition periods, or for machines used for Image Processing. Using AVR Studio 4, and AVR GCC, a C code for decoding the quadrature signals is being presented, which gives the pulse for one cycle and the direction in which the encoder is being rotated. With a change in direction, there is a change in the direction pulse, and the pulse indicates the completion of one transition cycle. It is explained in detail in the documentation.
Keywords: Quadrature decoder, AVR Studio v. 4.18, AVR GCC, transition state.