【正文】 0基于 AT89S52 單片機(jī)的頻率計(jì)設(shè)計(jì)中 文 摘 要頻率測(cè)量是電子學(xué)測(cè)量中最為基本的測(cè)量之一。頻率計(jì)主要是由信號(hào)輸入和放大電路、單片機(jī)模塊、分頻模塊及顯示電路模塊組成。AT89S52 單片機(jī)是頻率計(jì)的控制核心，來(lái)完成它待測(cè)信號(hào)的計(jì)數(shù)，譯碼，顯示以及對(duì)分頻比的控制。利用它內(nèi)部的定時(shí)/計(jì)數(shù)器完成待測(cè)信號(hào)頻率的測(cè)量。在整個(gè)設(shè)計(jì)過(guò)程中，所制作的頻率計(jì)采用外部分頻，實(shí)現(xiàn) 10Hz~2MHz 的頻率測(cè)量，而且可以實(shí)現(xiàn)量程自動(dòng)切換流程。以 AT89S52 單片機(jī)為核心，通過(guò)單片機(jī)內(nèi)部定時(shí)/計(jì)數(shù)器的門(mén)控時(shí)間，方便對(duì)頻率計(jì)的測(cè)量。其待測(cè)頻率值使用四位共陽(yáng)極數(shù)碼管顯示，并可以自動(dòng)切換量程，單位分別由紅、黃、綠 3 個(gè) LED 指示。本次采用單片機(jī)技術(shù)設(shè)計(jì)一種數(shù)字顯示的頻率計(jì)，具有測(cè)量準(zhǔn)確度高，響應(yīng)速度快，體積小等優(yōu)點(diǎn)。關(guān)鍵詞：頻率計(jì)；單片機(jī)；計(jì)數(shù)器；量程自動(dòng)切換 1目錄第一章 前言 ...............................................................................1 頻率計(jì)概述 ...........................................................................1 頻率計(jì)發(fā)展與應(yīng)用 .....................................................................1 頻率計(jì)設(shè)計(jì)內(nèi)容 .......................................................................1第二章 系統(tǒng)總體方案設(shè)計(jì) ...................................................................2 測(cè)頻的原理 ...........................................................................2 總體思路 .............................................................................3 具體模塊 .............................................................................3第三章 硬件電路具體設(shè)計(jì) ...................................................................5 AT89S52 主控制器模塊 .................................................................5 AT89S52 的介紹 ...................................................................5 復(fù)位電路及時(shí)鐘電路 ..............................................................6 引腳功能 ........................................................................7 單片機(jī)引腳分配 ..................................................................8 電源模塊 ............................................................................9 直流穩(wěn)壓電源的基本原理 ..........................................................9 電源電路設(shè)計(jì) ...................................................................10 放大整形模塊 ........................................................................11 分頻設(shè)計(jì)模塊 .......................................................................11 分頻電路分析 ...................................................................11 74LS161 芯片介紹 ................................................................12 74LS151 芯片介紹 ................................................................13 分頻電路 .......................................................................14 顯示模塊 ...........................................................................14 數(shù)碼管介紹 .....................................................................15 頻率值顯示電路 .................................................................15 檔位轉(zhuǎn)換指示電路 ...............................................................16第四章 系統(tǒng)的軟件設(shè)計(jì) ....................................................................17 軟件模塊設(shè)計(jì) .......................................................................17 中斷服務(wù)子程序 .....................................................................18 顯示子程序 .........................................................................19 量程檔自動(dòng)轉(zhuǎn)換子程序 ...............................................................20 應(yīng)用軟件簡(jiǎn)介 .......................................................................20 Keil 簡(jiǎn)介 .......................................................................21 protues 簡(jiǎn)介 ....................................................................22第五章 頻率計(jì)的系統(tǒng)調(diào)試 ..................................................................23 硬件調(diào)試 ...........................................................................232 電源模塊調(diào)試 ...................................................................23 整形模塊調(diào)試 ....................................................................24 分頻模塊調(diào)試 ...................................................................25 軟件調(diào)試 ...........................................................................25 Pouteus 軟件調(diào)試 ................................................................25 功能調(diào)試 .......................................................................26 系統(tǒng)調(diào)試 ............................................................................27 系統(tǒng)軟件調(diào)試 ...................................................................27 系統(tǒng)軟硬件調(diào)試 .................................................................27 誤差分析 ...........................................................................28第六章 總結(jié) .......................................................