Research On Key Technology And Equipment Development Of Lighting System Based On DALI Protocol

DALI (Digital Addressable Lighting Interface) has been widely applied in the field of lighting control, with its simple and convenient control mode, professional and meticulous lighting effects, flexible networking, etc. With the expansion of DALI system and the formation of new international standards, there is an urgent need by using general-purpose micro-controllers to achieve the new DALI standards, develop generic protocol stack, solve the implementation of Manchester coding and solve the conflict of multi-master communication, and so on. On the basis of studying the DALI standard protocol IEC62386, in view of the above key technical problems has been deeply studied. And equipment of DALI system based on DALI protocol is developed. The paper’s main work is summarized as following:(1) The features of Manchester coding are analyzed, several implementations of Manchester encoding and decoding are compared, and combining with the structure of DALI communication frame, the method of using the software program to implement the Manchester coding by using general micro-controller I/O port, combining with the external interrupt, timer and other peripherals, is identified. And the design of coding software is accomplished. The experimental verification is completed by building the hardware environment.(2) The DALI protocol has been well studied, the design method of the implementation of DALI protocol by using hierarchical block is determined. DALI protocol stack is developed with more adaptive characteristics, which does not depend on a particular micro-controller and can be easily transplanted on different kinds of MCUs and lays a solid foundation for implementation the development of the DALI standard equipment.(3) The DALI communication mechanism has been well studied. Through in-depth analysis of various conflict resolutions of OSI model, the methods of DALI instruction detection, setting priority instruction, the bus monitor and competition back-off delay are proposed to solve the communication conflict problem which is caused by taking the bus among multi-master devices in DALI system. Thus, the reliability of the DALI system communication is ensured.(4) The design of hardware and software of DALI system equipment is accomplished on the basis of the DALI protocol stack which has been implemented, including touch panels, and LED drivers. Moreover, the detailed analysis and summary of development process and design principles of DALI devices are also completed.(5) The DALI test system, which includes the master control device and LED driver, is set up. Reliability and stability of the DALI protocol stack are verified. Comprehensive test is also conducted by testing the performance and functionality of DALI equipment which has been implemented.