【正文】 digital tube in digital form. Keywords: PTC； MCU； A/D converters； RT characteristic III 目 錄 第 1 章 緒論 .................................................................................................................. 1 基于微處理芯片的智能儀器的發(fā)展現(xiàn)狀 ..................................................... 1 傳感技術(shù)相關(guān)概述 ......................................................................................... 2 本論文研究的目的和意義 ............................................................................. 3 第 2 章 系統(tǒng)硬件電路設(shè)計(jì) .......................................................................................... 4 系統(tǒng)硬 件設(shè)計(jì)思路概述 ................................................................................. 4 電壓表設(shè)計(jì)的總體方案 ................................................................................. 5 設(shè)計(jì)思路 .............................................................................................. 5 設(shè)計(jì)方案 ............................................................................................... 6 電壓表 A/D 轉(zhuǎn)換模塊 .................................................................................... 6 A/D 轉(zhuǎn)換器概述 ................................................................................... 6 ADC0808 主要特性 : ............................................................................ 7 ADC0808 外部各引腳功能 ................................................................. 7 ADC0808 內(nèi)部邏輯結(jié)構(gòu) ..................................................................... 9 數(shù)據(jù)處理模塊 ............................................................................................... 10 AT89C51 單片機(jī)性能介紹 ................................................................ 10 AT89C51 外部引腳功能 .................................................................... 10 單片機(jī)系統(tǒng)的相關(guān)電路 .................................................................... 12 顯示模塊 ....................................................................................................... 13 四位數(shù)碼管概述 ................................................................................ 14 原理圖及引腳圖 ................................................................................ 14 數(shù)碼管的譯碼方式 ............................................................................ 15 數(shù)碼管與單片機(jī)接口設(shè)計(jì) ................................................................ 15 外加的分壓電路 ........................................................................................... 17 整體的電路原理圖設(shè)計(jì) ............................................................................... 17 第 3 章 系統(tǒng)軟件部分設(shè)計(jì) ........................................................................................ 19 電阻測(cè)量儀的主程序 ................................................................................... 19 初始化程序 ................................................................................................... 20 A/D 轉(zhuǎn)換子程序 ............................................................................................ 21 顯示子程序 ................................................................................................... 22 第 4 章 系統(tǒng)運(yùn)行及測(cè)試結(jié)果分析 ............................................................................ 23 IV keil程序調(diào)試及 proteus 仿真 ....................................................................... 23 proteus 功能及使用概述 .................................................................... 23 調(diào)試過程中的問題及解 決方案 ...................................................... 24 實(shí)物完成及實(shí)物調(diào)試 ................................................................................... 26 電路板實(shí)物測(cè)試結(jié)果 ........................................................................ 26 數(shù)碼管亮度不夠的解決方案 ............................................................ 26 數(shù)碼管閃爍的解決方案 .................................................................... 27 實(shí)際電阻測(cè)量及結(jié)果分析 ........................................................................... 29 實(shí)際測(cè)量的情況 ................................................................................ 29 測(cè)量結(jié)果與分析 ................................................................................ 29 系統(tǒng)存在的不足 ................................................................................ 30 第 5 章 全文總結(jié)及展望 ............................................................................................ 32 工作總結(jié) ....................................................................................................... 32 展望 ............................................................................................................... 32 參 考 文 獻(xiàn) ................................................................................................................ 34 致 謝 ...................................................................................................................... 35 附錄 1............................................................................................................................. 1 單通道動(dòng)態(tài)數(shù)字電阻測(cè)量儀 1 單通道 動(dòng)態(tài) 數(shù)字 電阻測(cè)量儀 第 1 章 緒論 基于微處理芯片的 智能 儀器的發(fā)展現(xiàn)狀 隨著微電子技術(shù)的不斷發(fā)展，微處理器芯片的集成度越來越高，已經(jīng)可以在一塊芯片上同時(shí)集成 CPU、存儲(chǔ)器、定時(shí)器、計(jì)數(shù)器、并行和串行接口和A/D 轉(zhuǎn)換器等。 關(guān)鍵詞： PTC 電阻 （正溫度系數(shù)熱敏電阻） ； 單片機(jī) ； AD轉(zhuǎn)換器 ； 阻溫特性 II ABSTRACT This article is based on thermistor, MCU, A/D converters, and Nixie tube, design and pleted the dynamic resistance measurement system. PTC (positive temperature coefficient thermistor) the properties of heatsensitive materials mainly posed of three characterization, the resistance temperature properties are the basic properties of heatsensitive materials, it is the best scale to measure the performance of the heatsensitive. So the resistance test of it is very important. The system uses 89C51 microcontroller as the master chip, choice the ADC0809 to plete the conversion of analog to digital. With the external circuit designed by myself, bined with the singlechip to realization the test of PTCR’s resistance in the span of 13 kΩ。 利用本系統(tǒng)對(duì) PTC 熱敏