What is a Quadrature Counter and how is it used?

A Quadrature counter, also known as a Quadrature decoder, shaft decoder, or rotary decoder, is a type of digital input that uses a two-bit Gray code input to increase or decrease a value. The Quadrature counter works in combination with an optical or mechanical encoder, also known as a rotary or shaft encoder, to monitor the exact position, speed, and direction of a DC motor shaft.

The Quadrature counter works by reading the angular position of a shaft and converting it to high resolution digital data. This data is used for synchronizing moving parts for reliable, trouble-free operation. Optical encoders are commonly found in motors installed in industrial control applications, precision robotics, drive shafts, and rotating radar platforms.

Sealevel includes Quadrature counters in certain models of our R9 family of embedded RISC computers.