摘要
LED显示屏是利用发光二极管点阵模块或像素单元组成的平面式显示屏幕。由于它具有光效高、使用寿命长、组态灵活、色彩丰富以及对室内外环境适应能力强等优点，在国内外得到了广泛的应用。在短短的十来年中，LED 点阵显示屏就以亮度高、工作电压低、功耗小、小型化、寿命长、耐冲击和性能稳定的优点迅速成长为平板显示的主流产品，在信息显示领域得到了广泛的应用。LED的发展前景极为广阔，目前正朝着更高亮度、更高耐气候性、更高的发光密度、更高的发光均匀性、可靠性、全色化方向发展。
本文介绍了一款以单片机AT89S51为控制器的字幕型LED显示屏的硬件设计。该系统可实现中英文字符的显示和动态特效显示。并且可以通过级联的方式来扩大显示屏幕的尺寸已达到增加显示内容的目的。系统采用PC机作为上位机，上位机向单片机发送控制命令和上位机所存储的显示代码，AT89S51单片机接收并处理PC 机的控制命令以及显示代码，由显示驱动模块驱动一个16×16分辨率的LED点阵显示屏的扫描显示。PC机与单片机之间的通信采用RS—232C通信标准来实现。所选用的AT89S51单片机具有价格低廉兼程序写入方便的特点使得整个硬件系统方便维护和检修。除此之外，该系统只占用了单片机少量的I/O口和内存，为系统留下功能扩展的空间。加上串并转换器（译码器）74LS164，大大减少可I/O口的占用数目，为单片机扩展其他功能预留下来了空间。选择锁存器74LS373，74LS164的输出条件与74LS373的输入条件相匹配，可以实现锁存器对译码器的数据锁存。
关键字：AT89S51 单片机, LED 点阵显示, 串行通信
Abstract
The LED display is the use of a planar light-emitting diode dot matrix module or unit pixel display. Because it has the advantage of high luminous efficiency， long life, flexible configuration，rich colors and strong ability to adapt to the indoor and outdoor environment, both at home and abroad has been widely used.In just ten years, of LED dot matrix display with high brightness, lower voltages, the power consumption of the small, miniaturization, long service life, impact resistance and stable performance advantages of rapid growth of flat panel display of the mainstream of the products, in the field of information display a wide range of applications. LED development prospect, is currently towards a higher brightness, higher resistance to climate sex, higher light density, higher light uniformity, reliability, and the development direction of full-color.
This paper introduces a design of the LED lattice display system base on MCU AT89S51.The system can display in both Chinese and English characters of the show and from top to bottom and move around the magic show. And can be cascaded to expand the screen size to achieve increased content purposes. The PC sends control commands and display code to microcontroller, AT89S51 receives control commands from PC and shows the code, Driver module drives a 16×16-resolution LED lattice LED’s panel display scan showed. Communication between PC and the microcontroller using RS-232C communications standards. The characteristics that AT89S51 microcontroller is cheap and could be coded conveniently makes the whole system Convenient to Maintenance and Repair. In addition, the system will take up only a small amount of the MUC I/O and memory, so that the system has functional space for expansion. Plus string and converter (decoder) 74 LS164, greatly reducing can I/O mouth and the occupation of the number, for the single chip microcomputer expand other function reserve down space. Choose latches 74 LS373, 74 LS164 output conditions and 74 LS373 input conditions match, can realize the latches on decoder data lock to save.
Key words : AT89S51MCU, lattice LED’s panel display, serial communication
