LED Light On ARM-based Communication System

Wireless optical communication based on white-light LED illuminator is a newfocus in the filed of wireless communication. On the base of advanced lighting andcommunication technology, this visible light communication devices will turn into bean important part of the present communication family. Compared with other wirelesscommunications, this system has various advantages, such as low cost, low powerconsumption, high transmitting power, nonexistence of electromagnetic radiation, andresource conservation and environmental protection, etc. In the light of applications,there are requirements to connect indoor optical communication system with Internet.The main purpose of this thesis is to apply TCP/IP Agreement to white-light LEDoptical wireless communication system, to design an experiment setup which canrealize the interconnection of network signal with the optical system.Based on S3C2440ARM processor, uC/OS-II real-time operating system istailored and transplanted. According to processor and operating system, in order totransplant into the embedded system, an overall structure of embedded protocol stackis designed. The drive program for the network card DM9000in processor is designed.High speed network signal coding, delivery of data, and modulation of signals also areimplemented. For the sake of the avoidance of the flicker of LED in communicationprocess and the stability in the transmitting process, the coding based on differentialManchester technique downloaded into CPLD is realized. For the transplanteduC/OS-II system and embedded protocol stack, function tests in a ARM9developmentboard are carried on. Experiments show that network signals can be transmitted on thebase of the indoor white-light optical communication system. The system is stableand has certain anti jamming capability. It shows that the designed visible lightcommunication system has been interconnected with the internet.