【正文】 基于單片機的數(shù)字頻率計的 設(shè)計與 實現(xiàn) 摘要 隨著電子信息產(chǎn)業(yè)的發(fā)展，信號作為其最基礎(chǔ)的元素，其頻率的測量在科技研究和實際應(yīng)用中的作用日益重要，而且需要測頻的范圍也越來越寬。傳統(tǒng)的頻率計通常采用組合電路和時序電路等大量的硬件電路構(gòu)成，產(chǎn)品不但體積較大，運行速度慢，而且測量范圍低，精度低。因此，隨著對頻率測量的要求的提高，傳統(tǒng)的測頻的方法在實際應(yīng)用中已不能滿足要求。因此我們需要尋找一種新的測頻的方法。隨著單片機技術(shù)的發(fā)展和成熟，用單片機來做為一個電路系統(tǒng)的控制電路逐漸顯示出其無與倫比的優(yōu)越性。 本文闡述了以 AT89C51 單片機為控制器件的頻率測量方法，并用匯編語言進行設(shè)計，采用單片機智能控制，結(jié)合外圍電子電路，用以實現(xiàn)高低信號頻率的測量。 本文 設(shè)計 的是 一個簡易數(shù)字頻率計，被測信號可以是正弦波、三角波、方波。 首先，我們把待測信號經(jīng)過放大整形；然后把信號送入單片機的定時計數(shù)器里進行計數(shù)，獲得頻率值；最后把測得的頻率數(shù)值送入顯示電路里進行顯示。 本文從頻率計的原理出發(fā)，介紹了基于單片機的數(shù)字頻率計的設(shè)計方案，選擇了實現(xiàn)系統(tǒng)得各種電路元器件，并對硬件電路進行了仿真。 關(guān)鍵詞 單片機；頻率計；測量 Design and implementation of Digital Frequency Meter Based on Single Chip Mircropute Abstract Along with the development of electronic information industry, signal as the basic elements, the frequency measurement in scientific research and practical application is increasingly important, but also need the scope of frequency measurement is being more and more wide. The traditional frequency plan usually adopts binational circuits and the sequential circuits of the hardware circuit structure, product not only large size, speed is slow, and measuring range, and low accuracy of low. Therefore, as for frequency measurement requirements, the traditional method of frequency measurement in practical application already cannot satisfy requirements. Therefore, we need to find a new measuring method of frequency. Along with the development of technology and mature, use a singleship as a circuit system of control circuit shown its inparable advantages. In this paper, with AT89C51 microcontroller to control the frequency of measurement devices and assembly language design, intelligent control using single chip, bined with the external electronic circuit, can be high and low frequency measurements. This paper designs a simple digital frequency, the measured signal can be sine wave , square wave. F irstly, the rectangular pulse, which the measured signal is amplified and reshaped, is used as control throttle valve. Then, the frequency counter counts the number of the periods using the internal timer/counter of signal is chip so as to gain the frequency value of measured signal. Finally, the frequency value of measured signal is displayed through static display circuits. From the analysis of theory, and introduces the digital frequency plan based on single chip design, selection of the system, and have all kinds of circuit ponents of hardware circuit simulaion. Keywords Micor puter； Frequency； Measure 目錄 摘要 …… ..........................................................................................................................I Abstract .......................................................................................................................... II 第 1章 緒論 ................................................................................................................... 1 課題背景 .............................................................................................................. 1 單片機的發(fā)展及特點 .......................................................................................... 1 頻率計的基礎(chǔ)知識 .............................................................................................. 1 論文研究內(nèi)容 ...................................................................................................... 2 第 2章 單片機簡介及方案論證 ................................................................................... 3 AT89C51 單片機簡介 ........................................................................................... 3 單片機及其引腳說明 ................................................................................... 3 AT89C51 的定時 /計數(shù)器原理 ...................................................................... 5 定時 /計數(shù)器的工作模式 .............................................................................. 6 定時／計數(shù)器的特殊功能控制寄存器 ....................................................... 6 定時／計數(shù)器 (T0,T1)的控制寄存器 .......................................................... 7 數(shù)字頻率計設(shè)計的幾種方案 .............................................................................. 8 幾種方案的優(yōu)劣討論 .......................................................................................... 8 本次設(shè)計采用的方案 .......................................................................................... 9 本章小結(jié) .............................................................................................................. 9 第 3章 系統(tǒng)硬件設(shè)計 ................................................................................................. 10 數(shù)字頻率計工作原理及結(jié)構(gòu)框圖 .................................................................... 10 一般數(shù)字式頻率計的原理 ......................................................................... 10 基于單片機的數(shù)字頻率計原理 ................................................................. 10 電路原理圖 ........................................................................................................ 11 放大整形電路 .................................................................................................... 11 放大整形電路的必要性 ............................................................................. 11 放大整形電路的原理 ................................................................................. 11 分頻電路 ............................................................................................................ 15 分頻電路介紹 ............................................................................................. 15 四選一電路 ........................................................................................................ 16 顯示電路 ............................................................................................................ 17 顯示原理 ..................................................................................................... 17 顯示電路圖 ......................................................................