【正文】 ...................................................................3 ....................................................................................................................................................4第 2章 超聲波測距原理概述 .................................................................................................................................5 ....................................................................................................................................................6 超聲波發(fā)生器 ...........................................................................................................................................6 壓電式超聲波發(fā)生器原理 .......................................................................................................................6....................................................................................................................7第 3章 設計方案 .....................................................................................................................................................8 AT89S51單片機 ................................................................................................................................................8 超聲波測距系統(tǒng)構成 .....................................................................................................................................11 超聲波測距單片機系統(tǒng) .............................................................................................................................12 超聲波發(fā)射、接收電路 .............................................................................................................................12 ......................................................................................................................................................14 供電電路 .....................................................................................................................................................14 ..............................................................................................................................................15第 4章 系統(tǒng)軟件設計 ...........................................................................................................................................16 主程序設計 .....................................................................................................................................................16 超聲波測距程序流程圖 .................................................................................................................................20 超聲波測距程子序流程圖 .............................................................................................................................21第 5章 調(diào)試及性能分析 .......................................................................................................................................21 ..........................................................................................................................................................21 性能分析 .........................................................................................................................................................22參考文獻 .................................................................................................................................................................22附錄一：基于 AT89S51單片機超聲波測距系統(tǒng)電原理圖 .................................................................................24附錄二 基于 AT89S51單片機超聲波測距系統(tǒng) PCB圖 .......................................................................................25附錄三 基于 AT89S51單片機超聲波測距系統(tǒng)焊接組裝圖 ...............................................................................26附錄四 基于 AT89S51單片機超聲波測距系統(tǒng) C語言原程序 ...........................................................................27附錄五 元件清單 ...................................................................................................................................................413第 1章 緒論 課題背景，目的和意義傳感器技術是現(xiàn)代信息技術的主要內(nèi)容之一。s practical demand in measuring the precision 。This subject has introduced principle and characteristic of the ultrasonic sensor in detail ,and the performance and characteristic of onechip puter AT89S51 of Atmel Company ,and on the basis of analyzing principle that ultrasonic wave finds range ,the systematic thinking and questions needed to consider that have pointed out that designs and finds range ,provide low cost , the hardware circuit of high accuracy , ultrasonic range finder of miniature digital display and software design method