摘    要

本课题来源于服务企业的科研项目的一部分，涉及的后台监控系统以串行通信方式实现对上位机应用系统（单片机应用系统）显示内容的更新，提供调试、应用、售后于服务一体的功能，具有现实意义。针对小型点阵屏的后台监控系统一般协议不透明、现实内容字体修改不方便、无法更新当前时间等缺陷，同时系统软件开放性不够，很难实现不同厂家的配套使用。

利用计算机软件开发针对小型电子屏的后台监控系统，目标如下：1）显示内容可以自定义（含中英文、标点符号、数字等），但需要包含当前时间（年月日、星期、小时分钟秒）；2）显示内容字体可以进行改变（通过使用字库或采用其他方法）；3）针对不同字体可以自动生成点阵的字模；4）字模信息通过PC机串口或USB虚拟串口发送给下位机，下位机根据发送来的信息进行显示；5）串口通信速度、格式均可以控制；6）通信协议自定义；7）能够读取下位机显示的内容数据并在后台中进行保存；8）监控系统界面友好。

关键词： 51单片机；LED点阵；驱动电路；手写屏

Abstract

This subject comes from a part of the scientific research project of service enterprise. The background monitoring system in question can update the display content of upper computer application system (single chip computer application system) by serial communication, and provide debugging and application. The function of after-sale service is of practical significance. The background monitoring system of small lattice screen is not transparent, the font of real content is not convenient to modify, the current time can not be updated and so on. At the same time, the system software is not open enough, so it is difficult to realize the matching use of different manufacturers.

Using computer software to develop background monitoring system for small electronic screen, the objectives are as follows: 1) display content can be customized (including Chinese and English, punctuation marks, numbers, etc.), but need to include the current time (day, week, etc.) Hours, minutes, seconds); (2) the font of display content can be changed (by using the font or other methods), 3) the font of the lattice can be automatically generated for different fonts; 4) the font information is sent to the lower computer through the serial port of PC machine or the USB virtual serial port, which is displayed according to the information sent; 5) the speed of serial port communication, the format can be controlled; 6) the communication protocol is self-determined. Can read the content data displayed by the lower computer and save it in the background; 8) the interface of the monitoring system is friendly.

Keywords: 51 single chip microcomputer; LED lattice; driving circuit; handwritten screen
目    录

一、绪论1

（一）课题的研究意义1

（二）设计任务及要求1

（三）单片机的发展史2

（四）单片机的发展趋势3

二、系统的整体结构5

三、单片机介绍6

1、单片机引脚介绍9

2、复位电路设计9

2．时钟电路设计11

四、点阵电路介绍12

（一） LED点阵显示部分简介12

（二）LED驱动方式14

（三）手写笔电路设计16

五、软件设计17

（一）系统软件流程图17

（二）程序函数介绍18

1、延时函数18

2、行扫描函数18

3、手写笔中断函数18

（三）编程环境介绍19

总结23

参考文献24

附录 A25

（一）硬件电路原理图25

附录B26

（二）系统程序源代码26

致谢38