This is darn cool, use an optical mouse as a position sensor.
From the site: “Most optical mice are based on a technology where a small sensor take a small microscopic picture of the surface and detects the mouse movement by mathematically comparing sequential images. ”
This could make a dandy white line/direction sensor for a robot.
Interface to Optical Mouse Sensor
I suppose someone could also make a barcode scanner out of an optical mouse with little work… Humm….