A novel method for illumination and communication using white LED lights

LED lighting is regarded as the most potential lighting source due to its advantages, such as low power and long lifespan which is largely dependent on the temperature of the LED. So it is possible to predict the life of the LED lamp if the temperature can be read. The conventional method of reading information about a LED lamp is based on communication buses such as RS485 and CAN, but it is inconvenient to add communication lines. This paper proposes a novel compact lighting system which integrates the communication function into the conventional LED driving. Switching frequency modulation method is applied in the system so as to modulate data in the visible light. And the design of the receiver is also proposed, which identifies different frequencies and demodulate data. The introduced system achieves control over communication and dimmer independently at the same time. An experimental system is developed to demonstrate the effectiveness of the proposed approach.