Design And Implementation Of LED Color Screen And Its' Control System

The LED display is a new information display media which rapidly developed in global in late 1980s, now has become the mainstream products of the big screen display.The LED display as a new display media, along with large scale integrated circuit and the rapid development of computer technology, obtained the rapid development. Compared with with the traditional display media - colorful neon lights, pixel tube TV wall, four color magnetic flap, its high brightness, dynamic image shows good effect and low failure rate, less energy consumption, long service life, display content diversity, display mode is rich, high performance-to-price advantage has been widely used in many fields.Based on the upstairs, LED dot matrix display and its driving control system are analyzed and researched in this paper, and designed a kind of LED screen and control circuit can be used for indoor and outdoor large screen assembly and splicing, realizing displaying dynamic effect of Chinese characters move-up, down-on.Firstly, the paper expounds the principle of the LED displaying and shining, deeply analyzes its working principle and introduces various kinds of the LED screen, the LED screen display double-color Chinese character system designed in this paper is summarized. Based on this, the paper analyzes on several common driving method of LED display system,then determine to use the method of row scanning control drive mode.Secondly, detailed introduces hardware designing of the dot matrix screen display cascade module,and explains each key hardware part of the screen.Introdeces 74HC138, 74HC595, 74HC254 three main drive chip's function and application in actual circuit, this design makes the drive chips and LED screen design together.And then, designs a kind of LED screen panel control circuit based on AVR microcontroller, used to implement the hardware circuit to LED screen scanning control. Analysis the panel of each peripheral hardware interface circuit and function of practical circuit connection mode, lists the part program interface circuit and the explanation. Based on the practical circuit, also explains move-up and move-left display effect program design thought.Finally, in order to make the data updated intelligent and convenient second development, this paper designed the software of PC serial communication program based on VC++ development environment, completed the simple interface design, the data exchang each other between the PC and panel RS232 circuit.Through practical debugging, LED display can show the characters and the display module also can cascade display, and achieves the Chinese character moves up and down, right and left. Display can show clear character pictures, system is stable and reliable, and it can work under the PC control, it is a kind of practical application value and secondary development LED display system.