湖南工业大学专科毕业设计（论文）I摘 要近年来随着计算机在社会领域的渗透, 单片机的应用正在不断地走向深入，同时带动传统控制检测日新月益更新。在实时检测和自动控制的单片机应用系统中，单片机往往是作为一个核心部件来使用，仅单片机方面知识是不够的，还应根据具体硬件结构，以及针对具体应用对象特点的软件结合，以作完善。 模拟多通道压力系统是利用压力传感器采集当前压力并反映在显示器上，它可以分析压力过量程，并发出报警。并采用电子秤原理可根据输入单价准确的计算出物体的金额。本篇论文讨论了简单的倒计时器的设计与制作 ，对于倒计时器中的四位 LED 数码显示器来说，我为了简化线路、降低成本，采用以软件为主的接口方法，即不使用专门的硬件译码器，而采用软件程序进行译码。关键词 单片机，AT89S51， LED 数码管显示器， keil C51，倒计时器湖南工业大学专科毕业设计（论文）IIABSTRACTPermeate in the social realm along with the calculator in recent years, single slice the application of the machine just at constantly alignment thorough, arouse a traditional control an examination a day a new moon benefit renewal in the meantime.In solidly the hour the examination the single slice that controls with auto the machine the application the system, single slice machine usually Be a core parts to use, only single slice the machine aspect knowledge is not enough, return should according to concrete the hardware structure, and aim at concrete application the software ofwith the object characteristics combine to make perfect. Imitating many passage pressure systemses is to make use of pressure to spread the feeling machine to collect current pressure combine the reflection is on the display, it can analyze the pressure surfeit distance, erupting to report to the police.Combine the adoption electronics steelyard principle can according to input the amount of money that the unit price computes an object accurately This thesis discuss that pour the design and creation of the timer in brief, for pour four LED figures displays in the timer to say, I am for the sake of the simplification circuit,decline low cost, adopt to take software as the connect of lord a peoples method, do not use specialized hardware to translate the code machine namely, but adopt the software procedure to carry on translating code. Keyword：single slice machine，AT89 S51，The LED figures tube display，Keil C51，Pour timer湖南工业大学专科毕业设计（论文）III目录第 1 章 绪 论.11.1 课题背景.11.2 车速里程表的简介组成及原理.11.3 设计的整体思路.3 第 2 章 硬件的设计.62.1 单片机简介.62.2 AT89C52 系列单片机的介绍.72.3 里程表各部分电路介绍.92.3.1 霍尔传感器电路.92.3.2 定时计数器电路.112.3.3 外部中断.122.3.4 74HC573 驱动器.132.3.5LED 显示模块电路.15 第 3 章 软件的设计.173.1 普遍系统的总体设计.173.2 单片机应用软件的一般设计.173.3 车速里程表的软件设计.193.3.1 总体设计思路.193.3.2 子程序和主函数的设计.20 第 4 章 软件调试.234.1 程序的检测与调试.234.2PROTEUS 仿真过程.25 结束语.28 参考文献.29 致 谢.30 附录一 硬件设计原理图.31 附录二 程序清单.32 附录三 元器件清单.