Data communication using visible light allows transmission and reception of data through the light emitting diode. It employs the most advanced optical wireless communication technology in which light in the visible region (400nm-700nm) is used. It can work as an alternative to overcome the increasing wireless traffic demand. It is an unlicensed spectrum and is suitable for secure short range indoor communication.
The designed system consists of transceiver modules. The data transceiver transmits the data at the data rate of 9600 baud using pulse width modulation technique.ATMEGA328 microcontroller is used as a serial interface, modulator and the main processing unit. A high powered (3W) LED is employed which can switch data at a rapid rate. A lens is used with the LED which focuses the beam of light 2000 times. PIN diode is used as the data receiver. It can sense and translate the information sent by LED. A two way communication system is therefore developed to exchange data between two computers within the range of 2 meter at a data rate of 1.2 kbps-9.6 kbps for indoor applications.
The system has been tested for noise and error in data communication. It is also tested at different distances between the two transceiver modules. The performance of the system is analyzed using simulation and the actual system testing. Different graphs showing the performance of the simulated and actual system are obtained. The system works satisfactorily at a distance of 2 meter. The results are very much consistent with the expected values and the system proves to be very reliable and cost effective. The system can be successfully employed for data communication between shorter distances.