【正文】 ， 就在今天的數(shù)字電壓表和數(shù)字萬(wàn)用表中都有頻率計(jì) 的功能 。到今天頻率計(jì)已開(kāi)始并正在向智能、精細(xì)方向的發(fā)展。我國(guó)現(xiàn)階段電子產(chǎn)品的市場(chǎng)特點(diǎn) ,電子數(shù)字化發(fā)展很快。 本論文主要講述了數(shù)字頻率計(jì)的小集成制作。 課題研究的目的和意義 數(shù)字頻率計(jì)是計(jì)算機(jī)、通訊設(shè)備、音頻視頻等科研生產(chǎn)領(lǐng)域不可缺少的測(cè)量?jī)x器 。現(xiàn)在頻率計(jì)已是向數(shù)字智能方向發(fā)展，即可以很精確的讀數(shù)也精巧易于控制。當(dāng)今數(shù)字頻率計(jì)不僅是作為電壓表、計(jì)算機(jī)、天線電廣播通訊設(shè)備、工藝過(guò)程自動(dòng)化裝置。該數(shù)字頻率計(jì)可以對(duì)輸入信號(hào)幅度為 5V 的正弦波信號(hào)、方波信號(hào)、三角波信號(hào)進(jìn)行測(cè)量，測(cè)量的頻率范圍為 1Hz10MHz。摘要 摘 要 在電子技術(shù) 領(lǐng)域 中，頻率是最基本的參數(shù)之一，并且與許多電參量的測(cè)量方案、測(cè)量結(jié)果都有十分密切的關(guān)系，因此頻率的測(cè)量就顯得更為重要。軟件設(shè)計(jì)包括：?jiǎn)纹瑱C(jī)定時(shí)計(jì)數(shù)程序、 LCD 顯示程序等。 關(guān)鍵字 : 數(shù)字頻率計(jì)；信號(hào)；單片機(jī) 2 Abstract In the electronics field, the frequency is one of the most basic parameters, and is very closely related to many electrical parameters measurement program, measurement results, so the measurement of frequency bees even more important. The measurement of frequency designed in this text consist of two parts: the hardware and software design .the hardware circuitry take AT89S52 microputer as the core, to achieve the functions of controlling of the entire circuit of the test signals, data operations and choose 74LS160 as a frequency divider circuits, and through LCD display module shows measured data. Software design includes: MCU timer counting procedures, LCD display procedures and so on. The digital frequency meter can measure amplitude sine wave signal, square wave, triangle wave signals of which input signal is 5v, the frequency measured ranges from 1Hz to10MHz. The relative measurement error is 1%. This system has the advantage of pact structure , small size, high reliability, test frequency range, and easy use. Keyword: Figure frequency meter； Signal； Singlechip 數(shù)字頻率計(jì)的設(shè)計(jì) 3 目錄 1 緒論 ................................................................................................................................. 1 課題背景 ..................................................................................................................... 1 課題研究的目的和意義 ............................................................................................ 1 國(guó)內(nèi)外概況 ................................................................................................................ 2 課題的主要研究工作 ................................................................................................ 2 2 硬件電路的設(shè)計(jì) ............................................................................................................... 3 系統(tǒng)方案選擇 ............................................................................................................. 3 系統(tǒng)結(jié)構(gòu)及基本設(shè)計(jì)原理 ......................................................................................... 5 基本電路設(shè)計(jì) ............................................................................................................. 6 前置整形電路 .............................................................................................. 6 分頻電路 ..................................................................................................... 7 選通通道 ................................................................................................... 10 LCD1602 在系統(tǒng)中的應(yīng)用 ..................................................................................... 12 LCD1602 的特點(diǎn) ....................................................................................... 12 LCD1602 的工作原理 ............................................................................... 13 LCD1602 與單片機(jī)的連接 .................................................................... 14 控制核心 AT89S52 單片機(jī) ..................................................................................... 14 AT89S52 引腳功能描述 ......................................................................... 14 時(shí)鐘振蕩電路 ............................................................................................ 17 復(fù)位及復(fù)位電路設(shè)計(jì) ................................................................................ 18 3 軟件設(shè)計(jì) ......................................................................................................................... 20 主程序的設(shè)計(jì) ........................................................................................................... 20 LCD1602 顯示子程序流程 ....................................................................................... 21 4 系統(tǒng)調(diào)試 ......................................................................................................................... 22 系統(tǒng)的硬件調(diào)試 ....................................................................................................... 22 系統(tǒng)的軟件調(diào)試 ....................................................................................................... 23 頻率測(cè)量結(jié)果 ........................................................................................................... 24 4 5 總結(jié)與展望 ..................................................................................................................... 25 總結(jié) ........................................................................................................................... 25 展望 ........................................................................................................................... 25 致謝 ..................................................................................................................................... 26 參考文獻(xiàn) ............................................................................................................................. 27 附錄 1 .................................................................................................................................. 28 附錄 2 .................................................................................................................................. 29 數(shù)字頻率計(jì)的設(shè)計(jì) 1 1 緒論 課題背景 數(shù)字頻率計(jì) (DFM)是電子測(cè)量與儀表技術(shù)最基礎(chǔ)的電子儀表類(lèi)別之一 , 數(shù)字頻率計(jì)是計(jì)算機(jī)、通訊設(shè)備、音頻視頻等科研生產(chǎn)領(lǐng)域不可缺少的測(cè)量?jī)x器 ，而且它是數(shù)字電壓表 (DVM