A Low-Cost Free-Space Optical Communication Prototype

In this paper a prototype of a free-space optical communication system is proposed. The transmitter is equipped with a blue 1W LED and a low-cost microcontroller implementing a digital modulation scheme. The receiver converts the incoming light into a current through a photodiode and another identical microcontroller is employed to demodulate and decode the signal, after proper analog amplification and filtering. The system is thought to be used underwater for communication, e.g., between an autonomous underwater vehicle and a buoy. Preliminary results in air are shown to validate the functioning of the system with different values of solar illuminance.