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.   

The mouse and the Keyboard form the standard input unit for a Personal computer. The QWERT keyboard which is used in the PC comes with a PS2 connector or USB port connector. The PS2 keyboard uses a simple synchronous serial protocol using only two wires for communication. Due to its simplicity the PS2 keyboards are widely used with simple microcontroller based boards also. The PS2 keyboard always acts as a slave device which can send the equivalent ASCII value of the key which has been pressed to its master device which can be a PC or a microcontroller. The ZigBee is the name of a wireless protocol maintained by the IEEE 802.15 standard. This is a protocol specified for wireless Personal Area Network (PAN) using low powered wireless transceivers. There are already wireless transmitter and receiver modules which can do point to point communication.   

The PS2 mouse is an input device which can communicate with a host device using the PS2 protocol. It can be connected to a host device using the 6 pin mini DIN connector. The mouse will continuously give output which can be decoded to get the movement in the X-Y plane and also the status of the buttons on the mouse. The data read from the mouse can be decoded and processed to get the amount of change in position of the mouse with respect to the position at the previous read. This data is normally used in PCs to move a pointer in the screen. The PS2 protocol is a simple two wire synchronous protocol which makes it possible for the simple microcontroller board to interface the standard PS2 mouse or keyboard with it.This particular project demonstrates how to transmit the data read from a standard PS2 mouse from a microcontroller board to a distant PC.  

The Xbee is the brand name a wireless transceiver device which works on the ZigBee protocol. The ZigBee is the name of a wireless protocol maintained by the IEEE 802.15 standard. This is a protocol specified for wireless Personal Area Network (PAN) using low powered wireless transceivers. They can be used for simple point to point communication systems also. They have an approximate range of 10 to 100 meters and are used in industries, scientific fields, medical fields etc. The Xbee module even though uses complex packet data based Zigbee protocol for communicating with each other, they can communicate with other devices using simplest serial communication protocol and hence they are widely used in microcontroller base boards.This project demonstrates how to interface an Xbee module with the Arduino board and perform a full transmission and reception test between two Xbee modules generally known as loop back test. 

In earlier days the application of the wireless technology was limited mostly to simple point to point communication only replacing the cable based communication systems. The entire communication system itself became complex after the introduction of the computer and communication system based on computers. Several complex networked communication systems like LAN, WAN, PAN etc. came into use. To replace the cable based network communication system with wireless technology demands the design of complex wireless devices and wireless network protocols.The ZigBee is the name of a wireless protocol maintained by the IEEE 802.15 standard. This is a protocol specified for wireless Personal Area Network (PAN) using low powered wireless transceivers. There are already wireless transmitter and receiver modules which can do point to point communication.