Computer mouse has a wheel which is used to scroll the long documents or webpages for better viewing. This wheel uses encoders to identify the rotation cycle and direction. The idea is to identify the number of rotation of the wheel require to move a given distance. In one rotation wheel would travel 2*π*r distance, where r is the radius of the mouse scroll wheel. This relationship would be required in application in order to calculate the distance traveled by mouse wheel when scrolled.

Click on the video to see working demo of the idea.