Research On Intelligent Light Dimming System Based On DMX512 Protocol

Traditional dimming technology is used in analog dimming technology, in which there are many signal lines, the consistency of signal transmission is poor, and the operation is also not very convenient. The intelligent lighting system, making full use of electronic technology, communication and computer network technology to a variety of lighting fixtures within the building organically connected together to achieve effective management and control. However, there is no uniform international standards, the equipments of manufacturers are not compatible and can not form an effective lighting network, DMX512 network communication protocol proposed creating a digital dimming products compatible era. For these reasons, this study developed an intelligent light dimming system based on DMX512 protocol. Full text as follows:Through studying the development of intelligent lighting systems background, design intelligent dimming system according to centralized control theory. This design of intelligent dimming system includes main control computer, control terminal and dimming module, of which the main control computer and control terminal are used on the Shanghai AVTRON company's products, the most important task of this paper is the design of light dimming control circuit and programs.This design of dimming control circuit is based on the MC9S08AW32 Freescale 8-bit microprocessor core, using LM2675 chip as power module, which provides the operating voltage of +5V for the whole circuit, RS-485 communication bus used for the dimming datas transmission, Finally LM324 Quad chip realizes PWM waveform magnification zoom control to achieve the ballast operating voltage requirements. Through the analysis of the operating principle of dimming control circuit, draw out the dimming process flow chart, and with the help of the CodeWarrior development tools we edit, compile and debug the dimming circuit programs. Test shows that the design of the DMX512 dimming circuit can realize the stepless control of lights, proves the feasibility of design, and intelligent light dimming system could meet the needs of the market.