Using the image acquisition capabilities of the optical mouse sensor to build an absolute rotary encoder

In this paper, the optical mouse sensor is proposed as the main sensor of an absolute rotary encoder. The image acquired by the optical sensor is used to read a positioning binary code printed on an internal rotary surface to obtain the absolute rotary position. The two-dimensional image matrix acquisition is more robust than the single reading point approach used in other absolute rotary encoders (with only one pixel) where the position must be coded using random sequence codes. Additionally, the low cost of the optical sensor facilitates the development of inexpensive absolute rotary encoders.