Design Of LED Large Screen Data Transmittng Control System

LED large screen concentrates electronic technology, electro-optical technology, computer technology and communication technology, it has the features of high brightness, low power consumption and long service life, and has been widely used in industry, commerce and transportation, etc. At present, structures of LED screens and parameters required by users have become diverse, but traditional transmiting control systems only support uniform kind of screen structure and can't satisfy the requirements of users. So it's of wide applications and perspective to design a new transmiting control system which supports varieties of screen structures and satisfies requirements of different users.In this thesis a transmiting control system of fullcolor LED large screen based on FPGA is designed. On the basis of intensive studying the structure and principle of LED large screen, an overall designing scheme of the transmiting control system based on DVI interfaces, FPGA and Gigabit Ethernet is proposed. This designing scheme overcomes the drawback of traditional LED control systems that only support unform screen structure. It includes the following aspects:1. To satify the requirement of users to set the displaying parameters of the LED large screen dynamically, a user-friendly interface software is designed. This software is designed using C++ language based on VC++6.0 platform, and set the LED large screen parameters mainly using serial port communication. The experiment shows that this interface can set displaying control parameters such as screen structure, resolution, gray scale and brightness, etc.2. On the basis of intensive studying LED large screen display system, an LED large screen transmiting controller is designed. In the transmiting system, taking a 1024×768 resolution, 60Hz refreshing rate video source as the research object, video data from the DVI interface and displaying controlling parameters from the serial port are recombined, cached and transmitted using VHDL language, and a single-chip transmiting controller based on FPGA is implemented. Simulation using Modsim tools shows that the controller achieves the designing requirement.3. By analyzing existing long range video transmiting mode and working principle, a Gigabit Ethernet interface circuit is designed. By setting suitable transmiting and coupling mode, system parameters are determined, and realtime features and stability are ensured. The test shows that the interface can transmit data with Gigabit Ethernet in real time and properly.This data transmitting control system can recombine video data in different ways according to the different screen structures, and then transmit the controlling parameters set by the software and the recombined video data to the scanning control system stably through the Gigabit Ethernet. In that way the data transmitting control system can support multiple screen structures and the LED large screen control technique is impoved.