The Research Of LED Lighting Communication System

In the late1990s, people pay more attention to the wireless optical communication withquality of safe and confidential, large capacity of information transmission, good secret.At thesame time, under the trend of energy conservation and environmental protection. LED lightingtechnology has been developed rapidly. In2000visible light communication technology arisesat the historic moment. Its basic principle is that it uses light signal as the carrier, uses lightemitting diode as light source, through the spatial channel, and it transmits data at the speedwhich can’t be recognized by naked eyes. As borrowing lighting platform and transmittingdata signals by wireless means, so no longer need to rewiring, it can provides lighting as wellas green safe way of communication.This paper designs a kind of LED lighting system of communication. This system usesLED as light source. In the indoor environment, uses a serial data communication getsinformation from the computer A, transmits signal to STM32, STM32uses pulse positionmodulation to modulate source The receiver uses PIN photo-detector to receive the opticalsignal and converts it into electrical signal. The electrical signal transfers through the filter,voltage judgment, then is decoded into the original sigal. The original signal transfer to thecomputer B.This paper complete the serial data communication, constant current drive power source,the hardware design and software programming of the receiver part. Finally realize the datacommunication in one direction, with the distance of0.5m and the speed of9600baud rate.