【正文】 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量方案、測量結(jié)果都有十分密切的關(guān)系，因此頻率的測量就顯得更為重要。 本文設(shè)計的 測量 頻率計 由 硬件電路和軟件 設(shè)計兩 部分 組成 。 硬件電路 以 AT89S52 單片機 最小系統(tǒng)為核心，實現(xiàn)整個電路的測試信號控制、數(shù)據(jù)運算 等功能，選用 74LS160 作為分頻電路，并通過 LCD 顯示模塊顯示測量的數(shù)據(jù)。軟件設(shè)計包括：單片機定時計數(shù)程序、 LCD 顯示程序等。該數(shù)字頻率計可以對輸入信號幅度為 5V 的正弦波信號、方波信號、三角波信號進行測量，測量的頻率范圍為 1Hz10MHz。測量的相對誤差為 ? 1%。本系統(tǒng)具有結(jié)構(gòu)緊湊、體積小、可靠性高、測頻范圍寬、使用方便等優(yōu)點。 關(guān)鍵字 : 數(shù)字頻率計；信號；單片機 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)字頻率計的設(shè)計 3 目錄 1 緒論 ................................................................................................................................. 1 課題背景 ..................................................................................................................... 1 課題研究的目的和意義 ............................................................................................ 1 國內(nèi)外概況 ................................................................................................................ 2 課題的主要研究工作 ................................................................................................ 2 2 硬件電路的設(shè)計 ............................................................................................................... 3 系統(tǒng)方案選擇 ............................................................................................................. 3 系統(tǒng)結(jié)構(gòu)及基本設(shè)計原理 ......................................................................................... 5 基本電路設(shè)計 ............................................................................................................. 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 ....................................................................................... 12 LCD1602 的工作原理 ............................................................................... 13 LCD1602 與單片機的連接 .................................................................... 14 控制核心 AT89S52 單片機 ..................................................................................... 14 AT89S52 引腳功能描述 ......................................................................... 14 時鐘振蕩電路 ............................................................................................ 17 復(fù)位及復(fù)位電路設(shè)計 ................................................................................ 18 3 軟件設(shè)計 ......................................................................................................................... 20 主程序的設(shè)計 ........................................................................................................... 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 ............................................................................................................................. 27 附錄 1 .................................................................................................................................. 28 附錄 2 .................................................................................................................................. 29 數(shù)字頻率計的設(shè)計 1 1 緒論 課題背景 數(shù)字頻率計 (DFM)是電子測量與儀表技術(shù)最基礎(chǔ)的電子儀表類別之一 , 數(shù)字頻率計是計算機、通訊設(shè)備、音頻視頻等科研生產(chǎn)領(lǐng)域不可缺少的測量儀器 ，而且它是數(shù)字電壓表 (DVM)必不可少的部件。當今數(shù)字頻率計不僅是作為電壓表、計算機、天線電廣播通訊設(shè)備、工藝過程自動化裝置。多種儀表儀器 與家庭電器等許多電子