The Development of Computer Controlled Multicolor Illumination Network Using RGB based Light Emitting Diodes

Nowadays, the usage of the three main colors; red, green and blue (RGB), in optical technology is vast. RGB based light emitting diode (LED) luminary system has wide applications such as in LCD backlighting, commercial freezer lighting, white light illumination and etc. This paper presents the design of a personal computer (PC) based RGB illumination module. The system, consists of a microcontroller and LED driver, will enable users to select the desired color by just clicking on the CIE chromaticity chart (commision internationale de ´Eclairage) XYZ standard. The output color of the LEDs are corrected by varying the brightness of each RGB based LEDs using the microcontroller based module. The method used to control the brightness of the individual LEDs is pulse width modulation (PWM) where the duty factor of the current is varied. With the controllable colors, this project has applications such as in light therapy system to help ease seasonal mood swings, to improve sleeping patterns and to overcome jet lag syndromes of frequent travelers. It can also be widely explored for entertainment, presentations and decorations purposes.