【正文】 8 4 硬件設(shè)計 ........................................................................................................................................ 9 芯片的選擇 .................................................................................................................................. 9 控制器選擇 ........................................................................................................................ 9 超聲波接收電路 ............................................................................................................... 13 LED 顯示電路 ................................................................................................................ 15 高低頻報警電路 ............................................................................................................... 16 硬件圖 ....................................................................................................................................... 18 總體結(jié)構(gòu)框圖 .................................................................................................................. 18 系統(tǒng)總體硬件圖 ............................................................................................................... 19 5 軟件設(shè) 計 ...................................................................................................................................... 21 程序流程圖 ................................................................................................................................ 21 中斷流程圖 ................................................................................................................................ 22 系統(tǒng)子函數(shù) ................................................................................................................................ 22 蜂鳴器報警子程序和信號燈 .............................................................................................. 22 延時子程序 ....................................................................................................................... 23 單片機(jī)初始化子程序 ......................................................................................................... 23 系統(tǒng)總程序 ................................................................................................................................ 24 6 誤差分析 ...................................................................................................................................... 29 VI 由溫度產(chǎn)生的誤差 ............................................................................................................................29 7 結(jié)論與展望 ...................................................................................................................................30 結(jié)論 ...........................................................................................................................................30 不足之處及未來展望 ...................................................................................................................30 致謝 .................................................................................................................................................31 參考文獻(xiàn) ..........................................................................................................................................32 汽車倒泊防撞 警報 器的設(shè)計 1 1 緒論 課題來源 由于隨著科學(xué)技術(shù)和汽車工業(yè)的發(fā)展 ,許許多多的汽車安全裝置也 得 到大力的發(fā)展。 關(guān)鍵詞 ： 超聲波 ； 測距 ； 報警系統(tǒng) ； 單片機(jī) IV Abstract With China39。 目前超聲波測距已得到廣泛應(yīng)用 , 國內(nèi)一般使用專用集成電路根據(jù)超聲波測距原理設(shè)計各種測距儀器 , 但是專用集成電路的成本較高、功能單一。道路上、停車場變得越來越擁擠。 班 級： 學(xué) 號： 作者姓名： 年 月 日 I xx 大學(xué) xx 學(xué)院 機(jī)電 系 電子信息工程 專業(yè) 畢 業(yè) 設(shè) 計論 文 任 務(wù) 書 一、題目及專題： １、 題目 汽車倒泊防撞報警器的設(shè)計 ２、專題 二、課題來源及選題依據(jù) 由于隨著科學(xué)技術(shù)和汽車工業(yè)的發(fā)展 ,許多汽車安全裝置也得到大力的發(fā)展 .汽車上面安裝防撞報警器能夠極大地方便司機(jī)的駕駛 ,保障司機(jī)的安全 ,并且能在緊急的情況下自動剎車防止汽車之間的相撞 .隨著人們安全意識的提高 ,在汽車上安裝防撞倒泊警報器將必不可少 . 三、本設(shè)計（論文或其他）應(yīng)達(dá)到的要求： ，知道超聲波傳感器的主要性能特性； ，知道單片機(jī)的發(fā)展及應(yīng)用范圍； ，并選擇出一個合適的設(shè)計方案。此設(shè)計中，最終選擇的是 基于 AT89C51 單片機(jī)的超聲波防撞報警系統(tǒng)。倒車的總次數(shù)不斷增長 ,而汽車駕駛員視野又是非常有限 ,碰撞和拖掛的事故時有發(fā)生 ,夜間就更不安全了。而以單片機(jī)為核心的測距儀器可以實(shí)現(xiàn)預(yù)置、多端口檢測、顯示、報警等多種功能 , 并且成本低、精度高、操作簡單、工作穩(wěn)定可靠。s rapid economic development and the continuous improvement of living standards of residents, the residents have an increasing number of motor vehicles. Roads, parking lots bee more crowded. The total number of reversing the growing, and the car driver is a very limited field of vision, collision and trailer when the accident occurred the night even more dangerous. Drivers want to have a car alarm system, when in a moving vehicle can be continuously measured and the back of the rear obstacle distance (or the distance between cars and trucks), and can be displayed in the dashboard, and alerts from different range of different alarm signals in order to improve driving safety. Realtime digital display of the distance measured in the range of different distances can be issued a different sound and light alarm signal. At present, ultrasound has been wide ranging applications, the use of domestic ge neral ASIC design based on the principle of a variety of ultrasonic ranging range finder device, but the high cost of application specific inte