Description

Synopsis :

             Simultaneous dimming controlling and data transmission are usually required in a white LED based indoor visible light communication system. However, the dimingcontrolling of LED normally interferes the data transmission due to the modulation nonlinearity of LED. In order to solve this problem, a scheme by separating the LEDsfor the functions of dimming control and data transmission respectively is proposedin this paper. In the scheme, the LEDs used for dimming control function are driven by a dc amplified circuit, and the LEDs for data transmission are driven by a digital modulation circuit respectively. In this way,the modulation distortion to the data signalcaused by the modulation nonlinearity canbe avoided even if the dimming is at highlevel dc driven current. The proof-of-conceptexperiment of a 2.5Mbit/s visible lightcommunication system demonstrates that thedimming controlling and data transmission canbe realized simultaneously in a simple way,and the data transmission is not affected by the dimming controlling function. Comparedto previous methods, the scheme in this paperis simpler and cost effective, and makes sensewhen high rate data is transmitted in a visible light communication system.

Existing System:

• No network system is used
• Control of lights done only by wired communication
• The existing system involves time based switching ON/OFF the lighting system.
• No sensors are used for different illuminations

Proposed System:

• System has illumination intensity variation for the user movement and brightness of surroundings.
• Wireless communication between different lights used.
• Sensor used to find human body.

Block Diagram: 

              

       

Hardware & Software Requirements:

• Microcontroller (PIC/ARM)
• PIR
• LDR
• Zigbee
• Visual Basic
• Compiler (MPLAB/Keil)

Application:

• Wireless application
• Automatic increase and decrease of light intensity
• Network process