基于51單片機(jī)的超聲波液位傳感器──硬件設(shè)計(jì)

論文編號(hào):JD1189  論文字?jǐn)?shù):14151,頁(yè)數(shù):36  附任務(wù)書(shū)，開(kāi)題報(bào)告，文獻(xiàn)綜述，外文翻譯，中期檢查

畢業(yè)設(shè)計(jì)說(shuō)明書(shū)（論文）中文摘要

 本設(shè)計(jì)是在熟悉了單片機(jī)、超聲波、LED和AD694等性能后，以AT89C51單片機(jī)為核心，利用壓電式超聲波換能器對(duì)液位進(jìn)行自動(dòng)檢測(cè)；LED實(shí)時(shí)顯示測(cè)量數(shù)據(jù)；方便操作人員對(duì)系統(tǒng)檢測(cè)結(jié)果的監(jiān)控。系統(tǒng)硬件電路設(shè)計(jì)主要包含超聲波發(fā)射電路、接收電路、模擬信號(hào)輸出電路、數(shù)碼管顯示電路等。超聲波發(fā)射電路利用NE555發(fā)射脈沖經(jīng)過(guò)兩級(jí)功率放大和脈沖變壓器升壓激發(fā)換能器中的壓電元件產(chǎn)生超聲波信號(hào)。接收電路共由三個(gè)部分組成：第一部分為隔離電路；第二部分為信號(hào)放大電路；第三部分為門(mén)限電路。AT89C51單片機(jī)是整個(gè)超聲波液位傳感器測(cè)量系統(tǒng)的核心部分，主要任務(wù)是產(chǎn)生脈沖信號(hào)，通過(guò)發(fā)射電路驅(qū)動(dòng)超聲波換能器發(fā)出超聲波，并接收超聲波返回產(chǎn)生的下降沿信號(hào)，引發(fā)中斷。

關(guān)鍵詞  超聲波  測(cè)量  距離  單片機(jī)

畢業(yè)設(shè)計(jì)說(shuō)明書(shū)（論文）外文摘要

Title       Ultrasonic Level Sensor Based on MCS—51                                             
                       _       ——The Hardware Design                                      

Abstract
This design is familiar with the SCM, Ultrasonic and LED and AD694 properties. With AT89C51, ultrasonic transducer using the piezoelectric level for automatic detection; LED real-time display measurement data; Convenient operation personnel testing results of monitoring system.
The system hardware circuit design includes ultrasound circuit, receiving circuit, analog signal output circuit, digital tube display circuit, etc. Ultrasound circuit using NE555 firing pulse after two levels of power amplifier and pulse transformer transducer presser inspire piezoelectric element of producing ultrasonic signal. Receiving circuit altogether consists of three parts: The first part is isolating circuit; The second part is the signal amplifier circuit; The third part is the threshold circuit; AT89C51 is whole ultrasonic level sensor measuring system, the core part, Main task is to produce pulse signal circuit driver, through the launch ultrasonic transducer, and receives the ultrasonic issued ultrasonic produced along the signal drop back, triggering interrupts.

Keywords  ultrasonic  measurement  distance   microcontroller

目   次

1  引言 1
2  超聲波傳感器 2
2.1  超聲波的性質(zhì) 2
2.2  超聲波換能器 2
3  超聲波傳感器的測(cè)量原理 5
4  設(shè)計(jì)任務(wù)與要求 6
4.1  設(shè)計(jì)任務(wù) 6
4.2  系統(tǒng)總體設(shè)計(jì)要求 6
4.3  計(jì)時(shí)精度 7
5  硬件電路設(shè)計(jì) 9
5.1  整體電路設(shè)計(jì) 9
5.2  發(fā)射電路的選擇 9
5.3  接收電路 12
5.4  模擬信號(hào)輸出電路 15
5.5  數(shù)碼管顯示電路 18
5.6  單片機(jī)電路 19
5.7  電源整流電路 22
6  硬件電路仿真 23
6.1  發(fā)射電路的仿真 23
6.2  隔離電路的仿真 23
6.3  放大電路的仿真 24
7  軟件設(shè)計(jì) 26
7.1  主程序設(shè)計(jì) 26
7.2  子程序設(shè)計(jì) 26
結(jié)論 28
致謝 29
參考文獻(xiàn) 30
圖1  電路圖 31
表1  元器件列表 32