【正文】 e nop nop nop djnz 14h here ret Ranging in front of singlechip termination circuit input port single chipimplementation of the above procedure the port in a 40kHz pulse output signal afteramplification transistor T the drive to launch the first ultrasonic UCM40T issued 40kHzultrasonic pulse and the continued launch of the right and the left side ofthe circuit respectively then input port and the working principle and circuit infront of the same Reception and processing of ultrasonic Used to receive the first launch of the first pair UCM40R the ultrasonic pulsemodulation signal into an alternating voltage the opamp amplification IC1A and afterpolarization IC1B to is locked loop with audio decoder chip LM567 internalvoltagecontrolled oscillator center frequency of f0 1/ capacitor C4 determinetheir target in the launch of the carrier frequency on theLM567 input signal is greater than 25mV the output from the high jump 8 feet into alowlevel as interrupt request signals to the singlechip in front of singlechip termination circuit output port INT0 interrupt thehighest priority right or left location of the output circuit with output gate IC3A accessINT1 port singlechip while singlechip and received input IC3A interrupted by the process to identify the source of inquiry to deal with interrupt priority level for thefirst left right of the source code is as follows:receive1: push psw push acc clr ex1 related external interrupt 1 jnb right pin to 0 ranging from right to interrupt serviceroutine circuit jnb left pin to 0 to the left ranging circuit interruptservice routinereturn: SETB EX1 open external interrupt 1 pop acc pop psw retiright:...right location entrance circuit interrupt service routine Ajmp Returnleft:...left Ranging entrance circuit interrupt service routine Ajmp Return The calculation of ultrasonic propagation time When you start firing at the same time start the singlechip circuitry within the timerT0 the use of timer counting function records the time and the launch of ultrasonicreflected wave received you receive the ultrasonic reflectedwave the receivercircuit outputs a negative jump in the end of INT0 or INT1 interrupt request generates asignal singlechip microputer in response to external interrupt request theimplementation of the external interruptservice subroutine read the time differencecalculating the of its source code is as follows: RECEIVE0: PUSH PSW PUSH ACC CLR EX0。關鍵詞：超聲波，測距儀，單片機前言 隨著科技的發(fā)展，人們生活水平的提高，城市發(fā)展建設加快，城市給排水系統(tǒng)也有較大發(fā)展，其狀況不斷改善。超聲波發(fā)生器內部結構，它有兩個壓電晶片和一個共振板。強度較強的脈沖會比強度較弱的脈沖超過界限的時間早點，因此我們會認為強度較強的脈沖屬于較近的物體。是帶有鎖 定環(huán)的音頻譯碼集成塊LM567，內部的壓控振蕩器的中心頻率 f01/，電容 C4 決定其鎖定帶寬。第四步：設置回波放大器的所得來規(guī)格輸出，假定是 3 伏。主程序完成初始化工作、各路超聲波發(fā)射和接收順序的控制。而且超聲波指向性強，能量消耗慢，在介質中傳播距離遠，利用超聲波檢測距離，設計方面，計算處理簡單，并在測量精度方面也能達到工業(yè)要求。其中，CCD 探測具有使用方便、無需信號發(fā)射源、同時獲得大量的場景信息等特點，但視覺測距需要額外的計算開銷。超聲波是一種頻率大于20 kHz 具有方向性好、指向性強、傳播能量大、遇到雜質或界面時會產(chǎn)生反射波等特點的機械波。文獻[5]中提出一種基于STM8S單片機控制的超聲波測距系統(tǒng)的設計方案，在分析超聲波測距產(chǎn)生盲區(qū)和誤差原因的基礎上，設計時間增益補償電路和峰值時間檢測電路，并使用電容觸摸按鍵代替機電開關，確保正確捕捉回波的到達時間，提高測距精度．試驗驗證表明：~10m，%。設置在監(jiān)測點上的紅外探頭將人體輻射的紅外光譜變換成電信號，經(jīng)放大電路、比較電路送至門限開關，打開門限閥門送出TTL 電平至AT89C51單片機。LED 數(shù)碼管的基本組成是半導體發(fā)光二極管，常見的七段LED 數(shù)碼管結，它由7 個長條形狀的發(fā)光二極管組成，控制七段發(fā)光管的二進制代碼稱為段碼。文獻[11]中單片機開發(fā)時Proteus 軟件被廣泛使用,但仿真電路與實際電路的焊接與調試有很大的不同,需要特別的注意。紅外線傳感器探測到有人進入時會輸出一個電壓信號，經(jīng)放大器放大，然后送給單片機，從而由單片機控制整個系統(tǒng)，并發(fā)生聲光報警。文獻[16]中介紹基于Proteus與Keil的簡單搶答器項目設計，通過這個項目的設計，我們可以掌握單片機開發(fā)及設計流程，學生的思維得到了大大的拓展，通過仿真我們可以清楚項目設計中遇到的難題及項目能否成功實現(xiàn)。常用的傳感器有T40XX和R40XX系列，UCM40T和UCM40R系列等；其中T代表發(fā)射傳感器，R代表接收傳感器，40為中心頻率40KHZ。常溫下超聲波的傳播速度是334 米/秒,但其傳播速度V 易受空氣中溫度、濕度、壓強等因素的影響,其中受溫度的影響較大，如溫度每升高1 ℃, 米/ 秒。（2）逆壓電效應：在電介質的極化方向上施加電場，會產(chǎn)生機械變形，當去掉外加電場時，電介質的變形隨之消失，這種將電能轉化為機械能的現(xiàn)象稱逆壓電效應（超聲波發(fā)射器的工作原理）。所以在電路設計時，先確定C2,R2的取值，即C2=3300pf,R2=。電源用9V疊層電池；測量F3輸出頻率應為40KHz,否則應調節(jié)RP，發(fā)射波信號大于8m。電容CC3平衡F3和F4的輸出使波形穩(wěn)定。(R3+2R2)C2f=1/T=1/(t1+t2)187。它們所產(chǎn)生的超聲波的頻率、功率和聲波特性各有不同，因而用途也各有不同?！鱰 /2這就是所謂的時間差測距法 或：由于超聲波也是一種聲波, 其聲速C與溫度有關,表1列出了幾種不同溫度下的聲速。發(fā)射器將電磁振蕩轉換為超聲波向空氣發(fā)射，接收器將接受的超聲波進行聲電轉換變?yōu)殡娒}沖信號。面對目前計算機領域技術發(fā)展的最新環(huán)境, 匯編語言對于單片機開發(fā)來說已經(jīng)不是最適合的程序編寫技術了。通過分析超聲波測距誤差產(chǎn)生的原因，提高測量時間差到微秒級，以及用LM92 溫度傳感器進行聲波傳播速度的補償后，設計的高準確度超聲波測距儀能達到毫米級的測量準確度。此倒車防撞系統(tǒng)主要是利用超聲波的特點和優(yōu)勢，將超聲波測距原理和AT89C52 單超聲波測距報警器的設計與實現(xiàn)片機結合于一體，設計出一種基于單片機的倒車防撞報警系統(tǒng)。本文介紹了常用的顯示方法，研究了數(shù)碼管顯示時，如何有效的節(jié)約資源，主要是節(jié)約單片機的I/O 資源。文獻[8]中單片機AT89C51。隨著自動化等新技術的發(fā)展，傳感器的使用數(shù)量越來越大，一切現(xiàn)代化儀器、設備都離不開傳感器。文獻[3]中文章根據(jù)超聲波特征及測距原理，運用單片機和分體式超聲波傳感器設計了一款包括發(fā)射模塊、接收模塊、溫度補償模塊、顯示模塊和單片機外圍電路的簡單超聲波測距系統(tǒng)。文獻[2]中講述了隨著傳感器和單片機控制技術的不斷發(fā)展，非接觸式檢測技術已被廣泛應用于多個領域。‐5‐ 畢業(yè)設計（論文）英文翻譯 Kino Frequency Acoustic WaveMeasurement in Airquot in Proceedings of IEEE 1983 Ultrasonic Symposium October 312November 1983 Atlanta GA Abreu Freire Ranging: Envelope AnalysisGives Improved Accuracyquot Sensor Review 1992 Fritsch Signal Processing Techniques for HighAccuracy Ultrasonic Range Measurementsquot IEEE Transactions: Instrumentation andMeasurement August 1991 Taron TemperatureCompensated Ultrasonic Sensor Operating in Air for Distance and ProximityMeasurementquot IEEE Transaction on Industry Electronics 1982 .‐6‐ 畢業(yè)設計（論文）英文翻譯 Ultrasonic ranging system design Publicationtitle: Sensor : ：Ultrasonic ranging technology has wide using worth in many fields，such as the industriallocale，vehicle navigation and sonar engineering．Now it has been used in level measurement，selfguided autonomous vehicles fieldwork robots automotive navigation，air and underwater targetdetection，identification，location and so on．So there is an important practicing meaning to learn theranging theory and ways improve the precision of the ultrasonic ranging system in hand，satisfy the request of the engineering personnel for the ranging precision，the bound and the usage，aportable ultrasonic ranging system based on the single chip processor was developed．Keywords：Ultrasound r，Ranging System，Single Chip With the development of science and technology the improvement of peoplesstandard of living speeding up the development and construction of the system have greatly developed their situation is constantly to historical reasons many unpredictable factors in the synthesis of her time the ci