【正文】 ` I 摘 要 近年來隨著計算機在社會領(lǐng)域的滲透 , 單片機的應(yīng)用正在不斷地走向深入，同時帶動傳統(tǒng)控制檢測日新月益更新。在實時檢測和自動控制的單片機應(yīng)用系統(tǒng)中，單片機往往是作為一個核心部件來使用，僅單片機方面知識是不夠的，還應(yīng)根據(jù)具體硬件結(jié)構(gòu)，以及針對具體應(yīng)用對象特點的軟件結(jié)合，以作完善。 模擬多通道壓力系統(tǒng)是利用壓力傳感器采集當前壓力并反映在顯示器上，它可以分析壓力過量程，并發(fā)出報警。并采用電子秤原理可根據(jù)輸入單價準確的計算出物體的金額。本篇論文討論了簡單的倒計時器的設(shè)計與制作 ，對于倒計時器中的四位 LED 數(shù)碼顯示 器來說，我為了簡化線 路、降低成本，采用以軟件為主的接口方法，即不使用專門的硬件譯碼器，而采用軟件程序進行譯碼。 關(guān)鍵詞 單片機， AT89S51， LED數(shù)碼管顯示器， keil C51， 倒計時器 ` II ABSTRACT Permeate 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 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 of[with] the object characteristics bine to make perfect. Imitating many passage pressure systemses is to make use of pressure to spread the feeling machine to collect current pressure bine the reflection is on the display, it can analyze the pressure surfeit distance, erupting to report to the the adoption electronics steelyard principle can according to input the amount of money that the unit price putes 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 people39。s 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 ` III 目錄 第 1 章 緒 論 ....................................................................................................... 1 課題背景 ........................................................................................................... 1 車速里程表的簡介組成及原理 ....................................................................... 1 設(shè)計的整體思路 ............................................................................................... 3 第 2 章 硬件的設(shè)計 .............................................................................................. 6 單片機簡介 ....................................................................................................... 6 AT89C52 系列單片機的介紹 ........................................................................... 7 里程表各部分電路介紹 ................................................................................... 9 霍爾傳感器電路 ....................................................................................... 9 定時計數(shù)器電路 ..................................................................................... 11 外部中斷 ................................................................................................. 12 74HC573 驅(qū)動 器 ..................................................................................... 13 顯示模塊電路 ................................................................................... 15 第 3 章 軟件的設(shè)計 ................................................................................................ ...................................................................................................................................... 17 普遍系統(tǒng)的總體設(shè)計 ..................................................................................... 17 單片機應(yīng)用軟件的一般設(shè)計 ......................................................................... 17 車速里程表的軟件設(shè)計 ................................................................................. 19 總體設(shè)計思路 ......................................................................................... 19 子程序和主函數(shù)的設(shè)計 ......................................................................... 20 第 4 章 軟件調(diào)試 ................................................................................................ 23 程序的檢測與調(diào)試 ......................................................................................... 23 仿真過程 ........................................................................................... 25 結(jié)束語 ........................................................................................................................ 28 參考文獻 ................................................................................................................... 29 致 謝 ........................................................................................................................ 30 附錄一 硬件設(shè)計原理圖 ..................................................................................... 31 附錄二 程序清單