The applications of microcontroller are not limited to control simple electrical or electronic device but they are widely used in robotics and automotive industries nowadays. From simple rear view mirror control to complex engine control functions are done by the microcontroller. The microcontroller can even implement to automatically controlling the vehicle without a human driver inside it and such kinds of vehicles are called Unmanned Vehicles (UV). The UVs are commonly used research, military, rescue and agriculture fields. For any UVs the real time tracking of their path is necessary to ensure that they are moving through the proper way.This project demonstrates how it is possible to make a simplest path tracking device for a ground vehicle with the help of optical mouse. This project makes use of an optical mouse which works on PS2 protocol and is interfaced with an Arduino board to read the data from it.