【正文】 參數(shù)和程序，測距儀能測的范圍為27cm400cm，測距儀最大誤差不超過3cm。第六章 心得體會與總結(jié)此次畢業(yè)設(shè)計的課題為基于單片機的汽車倒車雷達的設(shè)計與實現(xiàn)控制系統(tǒng)的開發(fā)，這個課題是專業(yè)知識（單片機的應(yīng)用）和實際很好的一次結(jié)合。s the fourth film as LM324 parator inverting potential, the circuit shown in Figure , there is a threshold voltage, the voltage parator inverting input voltage. Threshold voltage adjustment potentiometer available. When the time, = 0, is low: when the time, = , is high. When the LM324 ultrasonic echo signal is detected, it outputs low level signal, this time for LM324 input voltage is less than the threshold voltage, the LM324 to the output level signal, leading to end of data acquisition PC. On the contrary, the output signal to the PC for the low end of data acquisition. This part of the parator adjusted properly if there could be some problems, such as the output will be highfrequency output. This is because the parator is very sensitive to small changes in the signal causes the output values ??and the mutual transformation. Use of the positive feedback of the parator hysteresis to reduce sensitivity of the parator can reduce the interference. Because the amplified echo signal amplitude is large, so then by setting the appropriate threshold can be effectively stable signal. Use of adjustable potentiometer is a more convenient way. Needs the input of the parator reference voltage stability need to add capacitance stability. Reasonable adjustment potentiometer, select the parison reference voltage, allows more accurate and stable measurement.參考文獻《單片機應(yīng)用技術(shù)教程》………………………………………… 張洪潤 藍清華主編清華大學(xué)出版社 1997年5月出版《單片機原理與控制技術(shù)》…………………………………………………陳麗芳主編東南大學(xué)出版社 2003年7月出版 《單片機應(yīng)用技術(shù)》…………………………………………………………劉守義主編 西安電子科技大學(xué)出版社 2002年8月出版《單片微機系統(tǒng)》……………………………………………………………蔣力培主編 機械工業(yè)出版社 2004年2月出版《超聲手冊》……………………………………………………………………馮諾主編南京大學(xué)出版社 2002年5月出版《超聲波測距儀在汽車安全系統(tǒng)中的應(yīng)用》………………………………肖質(zhì)紅主編萬里學(xué)院學(xué)報出版 2007年5月出版．《超聲波測距系統(tǒng)的設(shè)計與實現(xiàn)電子技術(shù)應(yīng)用》…………………………徐國華主編l995年12月出版《基于超聲波測距系統(tǒng)的溫度補償田勝軍》…………………… 秦宣云 何永強主編2007年5月出版本科畢業(yè)設(shè)計（論文）開題報告學(xué)生姓名學(xué)號專業(yè)班級指導(dǎo)教師職稱單 位課題性質(zhì)設(shè)計□ 論文□課題來源科研□ 教學(xué)□ 生產(chǎn)□ 其它□畢業(yè)設(shè)計（論文）題目開題報告（闡述課題的目的、意義、研究現(xiàn)狀、研究內(nèi)容、研究方案、進度安排、預(yù)期結(jié)果、參考文獻等）一、論文研究的目的、意義 現(xiàn)實意義：指出現(xiàn)實當(dāng)中存在這個問題，需要去研究，去解決，本課題的研究有什么實際作用。期刊格式：[序號]主要責(zé)任者．文獻題名[J]．刊名，年，卷（期）：起止頁碼．如：[1] 周穎，[J].商業(yè)時代，2006 [2] [J].上海金融學(xué)院學(xué)報，2004著作格式：[序號]主要責(zé)任者．文獻題名[文獻類型標(biāo)識]．出版地：出版者，出版年. 起止頁碼．如：[1] [M] ，2001報紙文章：[序號]主要責(zé)任者. 文獻題名[N]. 報紙名，出版日期（版次）．電子文獻：[序號]主要責(zé)任者. 電子文獻題名[電子文獻及載體類型標(biāo)識].電子文獻的出處或可獲得地址，發(fā)表或更新日期/引用日期（任選）．指導(dǎo)教師意見：指導(dǎo)教師簽名：年 月 日教研室意見：審查結(jié)果： 同 意□ 不 同 意□教研室主任簽名：年 月 日電 子 科 技 大 學(xué)畢業(yè)設(shè)計(論文)成績考核表題目：教學(xué)中心： 學(xué)生姓名： 學(xué)號：專業(yè)：指導(dǎo)教師： 職稱： 所在單位： 指導(dǎo)教師意見： 簽字： 年 月 日 評審意見： 評閱人： 年 月 日 答辯意見：答辯小組組長簽名： 年 月 日畢業(yè)設(shè)計（論文）成績1．設(shè)計說明書（論文報告） 分總分：（等級： ）2．答辯 分3．平時成績 分學(xué)校意見：年 月 日1． 學(xué)生畢業(yè)設(shè)計（論文）正本存教學(xué)中心。在介紹方法時簡單寫一下通過此方法研究出了什么內(nèi)容。經(jīng)過自己親手的實踐過程，使我學(xué)到了許多課本里學(xué)不到的東西，積累了一定的經(jīng)驗和教訓(xùn)，在實踐的過程中鍛煉了自己的動手能力和團隊協(xié)作能力，為自己以后能更快的投入工作提供了一定的經(jīng)驗！ 英語翻譯Microcontroller reset is to make the CPU and other system features are in a defined initial state, and from this state to work, reset PC = 0000H, the microcontroller from the first a unit to take mand. Whether it is connected to the microcontroller when the power is just the beginning, or after power failure or failure to be reset. MCU reset conditions are: the RST pin must be coupled with continued two machine cycles (ie 24 oscillations) is high. Clock frequency in this article 12MHz, each machine cycle is 1μs, then the only 2μs time high above, appears in the RST pin high after the implementation of the second machine cycle reset.Reset circuit constituted by the capacitor series resistance, bined with the map, the capacitor voltage can not be mutatedin nature, can know when the system is a power, RST will be a foot high, and that the duration of this high by the circuit The RC values ??to decide. Appropriate bination of RC values ??can ensure a reliable reset. The circuit in addition to a poweron reset functions, to reset, just press the RESET button, then power through resistance, voltage, reset in the RESET high end.Clock circuit main task is to provide a working frequency. Internal microcontroller used to form a highgain inverting amplifier oscillator, the amplifier input and output are XTAL1 and XTAL2, XTAL1 and XTAL2 on the external clock source can constitute a clock circuit. Both internal and external clock generation mode. This design uses the internal clock generation means. Circuit connection shown in Figure , both ends of the jumper XTAL1 and XTAL2 crystal resonator (oscillator frequency 12MHZ), and internal selfexcited oscillator inverter constituted. The issue of pulse timing control directly into the onchip ponents. In addition, the capacitance of the frequency tuning role, as an external crystal oscillator, capacitor selection 20pF, practical application, and capacitor resonator near as possible to install in the SCM to reduce the parasitic capacitance, the oscillator stable and reliable work.Ultrasonic transmitting circuit includes ultrasonic generator circuit and the ultrasonic transmitter control circuit of two parts,