【正文】 urement tools, performance requirements have bee more sophisticated. Digital voltmeter has been achieved meas urement automation, improve efficiency indispensable instruments, digital measuring equipment is currently one of the main direction of development. Digital can not develop without the application of SCM, SCM is an integrated circuit chip, using technology to large scale data processing with a microprocessor (CPU) concentrated in a single chip. With the rapid development of single chip microputer, microcontroller technology has bee a national important indicator of the level of modern technology. SCM can be individually required to plete the modern industrial control intelligent control, which is the biggest single chip features. Microputer control system can replace the previous use of plex electronic circuits or digital circuits of the control system software control can be achieved and can achieve intelligent. Based on these ideas, the design uses ATMEL Corporation AT89C52 digital DC voltage meter system design, its main function is as follows: Measurement 05V DC voltage, the minimum resolution of , using 8 LED digital control module displays the measured voltage stability. The design AT89C52 microcontroller as the core, successive approximation A / D converter ADC0808 analog to digital conversion, using 8 LED digital control module shows the design of digital DC voltage meter system. In the design details of the body parts of the system software iii and hardware circuits, introduces successive approximation conversion circuit theory, 89C52 features, ADC0809 features and applications, 8segment LED digital control applications. The circuit design of novel, powerful, and scalable. Key words: Voltage Measurements SCM AT89C52 ADC0808 LED Digital Tube iv 目 錄 摘 要 ............................................................ i Abstract........................................................... ii 第 1 章 緒論 ........................................................ 1 背景 ....................................................... 1 數(shù)字電壓表及特點 ........................................... 2 數(shù)字電壓表的現(xiàn)狀以及發(fā)展趨勢 ............................... 3 選題的目的和意義 ........................................... 4 論文主要內(nèi)容 ............................................... 5 第 2 章 系統(tǒng)總體設(shè)計 ................................................ 6 系統(tǒng)的功能要求 ............................................. 6 方案論證 ................................................... 6 單片機的選擇 .......................................... 6 A/D 轉(zhuǎn)換器的選擇 ...................................... 7 系統(tǒng)設(shè)計框圖 .......................................... 8 第 3 章 硬件電路設(shè)計 ................................................ 9 單片機介紹 ................................................. 9 單片機的內(nèi)部結(jié)構(gòu) ...................................... 9 單片機發(fā)展概況 ....................................... 11 單片機的應(yīng)用領(lǐng)域 ..................................... 13 單片機 AT89C52............................................. 15 AT89C52 的主要性能參數(shù) ............................... 15 功能概述 ............................................. 15 功能引腳 ............................................. 16 晶振電路 ............................................. 18 復(fù)位電路 ............................................. 19 A/D 轉(zhuǎn)換模塊設(shè)計 ........................................... 21 A/D 轉(zhuǎn)換原理 ......................................... 21 ADC0808 簡介 ......................................... 23 ADC0808 與單片機 AT89C52 的接口電路： ................. 26 LED 顯示電路 ............................................... 27 LED 數(shù)碼管簡介 ...................................... 27 LED 數(shù)碼管顯示方式 ................................... 30 LED 顯示器與單片機 AT89C52 的接口電路 ................. 31 電源電路設(shè)計 .............................................. 31 設(shè)計原理圖 ................................................ 32 原件清單 .................................................. 33 第 4 章 系統(tǒng)軟件電路設(shè)計 ........................................... 34 系統(tǒng)程序的設(shè)計 ............................................ 34 初 始化程序 ........................................... 34 主程序 ............................................... 34 顯示子程序 ........................................... 34 v A/D 轉(zhuǎn)換測量子程序 ................................... 34 匯編源程序 ................................................ 35 第 5 章 軟件的調(diào)試與仿真 ........................................... 36 編譯程序 .................................................. 36 系統(tǒng)功能的仿真 ............................................ 36 Proteus 介紹 ......................................... 37 系統(tǒng)功能仿真 ......................................... 39 第 6 章 系統(tǒng)的防干擾措施設(shè)計 ....................................... 45 干擾的來源以及造成的后果 .................................. 45 干擾的來源 ........................................... 45 干擾造成的后果 ....................................... 45 抗干擾措施的設(shè)計 .......................................... 46 硬件抗干擾措施 ....................................... 46 軟件抗干擾措施 ....................................... 47 第 7 章 設(shè)計總結(jié) ................................................... 50 參考文獻 ........................................................... 52 附 錄 ........................................................... 53 附錄一 電壓表匯編源程序 ....................................... 53 附錄二 硬件原理圖 ............................................. 56 附錄三 外文資料 ............................................... 57 中文翻譯 ............................................... 63 致 謝 ........................................................... 68 太原理工大學(xué)陽泉學(xué)院 — 畢業(yè)設(shè)計說明書 1 第 1 章 緒論 背景 電壓是一個基本物理量 ， 是電路中表征電信號能量的三個基本參數(shù) (電壓 ， 電流 , 功率 )之一 。在設(shè)計的正文中詳細介紹了軟硬件系統(tǒng)的各部分電路，介紹了逐次逼近式轉(zhuǎn)換電路的原理， 89C52 的特點， ADC0809 的功能和應(yīng)用， 8 段 LED 數(shù)碼管的應(yīng)用。 基于以上思路，本設(shè)計采用 ATMEL 公司的 AT89C52 實現(xiàn)數(shù)字直流電壓表系統(tǒng)的設(shè)計，其主要具有如下功能：