【正文】 B V1 , LOOP 。 打開V3開始化霜 MOV R0 , 50 。溫度設(shè)定值存放在閃爍存儲(chǔ)器上即使斷電也可保存。讀取冷藏室溫度設(shè)定值 MOVC A , DPTR LCALL DLY_100MS 。讀取冷藏室溫度設(shè)定值 MOVC A, DPTR LCALL DLY_100MS 。清空各狀態(tài)位 SETB EX0 。選擇邊沿觸發(fā)方式 　　 SETB EA 　　　 ；CPU開中斷 RET 整個(gè)DS18B20程序調(diào)用方式是uint ReadTemperature(void)，該函數(shù)主要包括了對(duì)DS18B20的初始復(fù)位，讀溫度，溫度轉(zhuǎn)換，計(jì)算溫度等子程序，并將轉(zhuǎn)換后的數(shù)據(jù)擴(kuò)大10倍返回主函數(shù)，提供給下一個(gè)函數(shù)使用。（１） 對(duì) DS18B20 操作時(shí)，首先要將它復(fù)位將DQ線拉低480至960s，再將數(shù)據(jù)線拉高15至60s，然后DS18B20發(fā)出60至此240s的低電平作為應(yīng)答信號(hào)，這時(shí)主機(jī)才能對(duì)它進(jìn)行其它操作。前兩個(gè)就是溫度，將高低字節(jié)分別放入b和a中。讀操作：主機(jī)將數(shù)據(jù)線從高電平拉至低湖南人文科技學(xué)院畢業(yè)設(shè)計(jì) 17 電平1s以上，再使數(shù)據(jù)線升為高電平，從而產(chǎn)生讀起始信號(hào)從主機(jī)將數(shù)據(jù)線從高電平拉至低電平起15s至60s，主機(jī)讀取數(shù)據(jù)每個(gè)讀周期最短的持續(xù)期為60s周期之間必須有1s以上的高電平恢復(fù)期。當(dāng)采用12位分辨率時(shí)，轉(zhuǎn)換的時(shí)間約為750ms。發(fā)送溫度轉(zhuǎn)換命令的寫操作：將數(shù)據(jù)線從高電平拉至低電平，產(chǎn)生寫起始信號(hào)從DQ 線的下降沿起計(jì)時(shí)，在 15s到60s這段時(shí)間內(nèi)對(duì)數(shù)據(jù)線進(jìn)行檢測(cè)，如數(shù)據(jù)線為高電平則寫1；若為低電平，則寫0，完成了一個(gè)寫周期在開始另一個(gè)寫周期前，必須有1s以上的高電平恢復(fù)期每個(gè)寫周期必須要有60 s以上的持續(xù)期。因?yàn)閺腄S18B20中讀出的二進(jìn)制值必須先轉(zhuǎn)換成十進(jìn)制值，才能用于字符的顯示。在采用12位轉(zhuǎn)換精度時(shí)，就是實(shí)際的十進(jìn)制溫度值?？刂瞥绦蚴歉鶕?jù)用戶設(shè)定的溫度值和DS18B20實(shí)時(shí)測(cè)得溫度值相比較，從而決定是否需要制冷，并在液晶屏上顯示其工作狀態(tài)。當(dāng)ysj=1，繼電器閉合，壓縮機(jī)通電工作；當(dāng)ysj=0時(shí)，繼電器斷開，壓縮機(jī)停止工作。直到故障解除，然后重行啟動(dòng)電冰箱程序。 為了避免冷氣泄露，節(jié)約電能還需要進(jìn)行電冰箱門關(guān)好與否的檢查，因此在程序中又設(shè)置一判斷門是否關(guān)好的語句能夠及時(shí)地提醒用戶門沒關(guān)好。中斷服務(wù)程序主要完成電源欠壓、過壓處理、開門狀態(tài)檢查及處理和溫度采集等。當(dāng)停電或其它原因引起箱內(nèi)溫度上升超過18℃時(shí)，冰箱自動(dòng)報(bào)警，超溫報(bào)警指示蜂鳴響起，提醒用戶采取應(yīng)急措施。 硬件調(diào)試比較簡(jiǎn)單，首先檢查電路的焊接是否正確，然后可用萬用表測(cè)試或通電檢測(cè)。對(duì)于顯示子程序，是最首當(dāng)其沖的，只需要能將所要顯示的內(nèi)容全部顯示，并且顯示在恰當(dāng)?shù)奈恢?，如果不能顯示準(zhǔn)確，就有可能導(dǎo)致后面程序很難寫出。 其次最重要的一個(gè)程序就是實(shí)時(shí)測(cè)量環(huán)境溫度的DS18B20程序，它能否正常工作關(guān)系到整個(gè)系統(tǒng)是否能夠正常工作；對(duì)于其的調(diào)試主要看是否能夠顯示測(cè)得的溫度，還有在其工作的時(shí)候，用手指去捏住DS18B20看溫度是否變化，其次另外拿支溫度計(jì)測(cè)當(dāng)時(shí)的溫度，和DS18B20測(cè)得的溫度比較一下看誤差是否比較大。如若不能正常進(jìn)行，再返回程序設(shè)計(jì)原理和C語言的語法、數(shù)據(jù)轉(zhuǎn)換規(guī)則仔細(xì)推理程序是否寫錯(cuò)。該控制器以89C51單片機(jī)為控制核心，能夠?qū)崿F(xiàn)對(duì)冷凍室、冷藏室溫度的檢測(cè)和顯示，同時(shí)，還能實(shí)現(xiàn)對(duì)冷凍室溫度的設(shè)定，還能實(shí)現(xiàn)對(duì)壓縮機(jī)的開機(jī)和停機(jī)計(jì)時(shí)，并能對(duì)電冰箱的運(yùn)行情況進(jìn)行全方位的監(jiān)控，實(shí)時(shí)的進(jìn)行故障報(bào)警。通過此項(xiàng)設(shè)計(jì)的分析可得到如下結(jié)論： 、體積小、價(jià)格低廉的8位STC89C52單片機(jī),可以做出可行、可靠性強(qiáng)的自動(dòng)控制產(chǎn)品電冰箱溫度的控制系統(tǒng)。 ，利用軟件抗干擾也可以達(dá)到精度不高的要求，而且，節(jié)省了硬件資源，降低了產(chǎn)品設(shè)計(jì)成本，有助于產(chǎn)品的推廣、民用化。 。謝 辭三年的大學(xué)生活在這個(gè)季節(jié)即將畫上一個(gè)句號(hào)，而于我的人生卻只是一個(gè)逗號(hào)，我將面對(duì)又一次征程的開始。在這段忙碌而又充實(shí)的一段時(shí)光里有治學(xué)嚴(yán)謹(jǐn)而又親切的老師，有互相幫助的同學(xué)，更有積極、向上、融洽的學(xué)習(xí)生活氛圍。不僅學(xué)到了更多的理論知識(shí)，擴(kuò)展了知識(shí)面，提高了自己的實(shí)際操作能力；而且學(xué)會(huì)了如何去學(xué)習(xí)新的知識(shí)，學(xué)會(huì)了面對(duì)困難和挑戰(zhàn)，學(xué)會(huì)了團(tuán)結(jié)合作，互助互利。在此，我要衷心感謝張娟梅老師，從畢業(yè)設(shè)計(jì)的開始到畢業(yè)論文的最終定稿，張老師給了我細(xì)心的指導(dǎo)和幫助。此外，她嚴(yán)謹(jǐn)?shù)闹螌W(xué)態(tài)度和忘我的工作精神值都得我去學(xué)習(xí)。此外，在我撰寫論文期間，還得到了同班同學(xué)的支持和鼓勵(lì),每當(dāng)我遇到困難進(jìn)行不下去的時(shí)候，他們都能耐心細(xì)致地給我講解，幫助我度過了一個(gè)又一個(gè)難關(guān)，我的畢業(yè)設(shè)計(jì)和論文才得以順利地完成，在此我衷心地對(duì)他們說聲“謝謝”。[3][M].北京:機(jī)械工業(yè)出版社,2008 [4]樓然苗,[M].北京:北京航天航空大學(xué)出版社,2007 [5](第三版)[M].北京:清華大學(xué)出版社,2005 [6]張春芝，《電冰箱單片機(jī)控制系統(tǒng)的設(shè)計(jì)》，北京工業(yè)職業(yè)技術(shù)學(xué)院學(xué)報(bào)。Technical Institute of ,(03)：2126 附　錄 附錄一：總體電路圖52外文資料譯文英文原文：Singlechip1 The definition of a singlechip Singlechip is an integrated on a single chip a plete puter system. Even though most of his features in a small chip, but it has a need to plete the majority of puter ponents: CPU, memory, internal and external bus system, most will have the Core. At the same time, such as integrated munication interfaces, timers, realtime clock and other peripheral equipment. And now the most powerful singlechip microputer system can even voice, image, networking, input and output plex system integration on a single chip. Also known as singlechip MCU (Microcontroller), because it was first used in the field of industrial control. Only by the singlechip CPU chip developed from the dedicated processor. The design concept is the first by a large number of peripherals and CPU in a single chip, the puter system so that smaller, more easily integrated into the plex and demanding on the volume control devices. INTEL the Z80 is one of the first design in accordance with the idea of the processor, From then on, the MCU and the development of a dedicated processor parted ways. Early singlechip 8bit or all of the four. One of the most successful is INTEL39。s with the big consumer electronics product development, singlechip technology is a huge improvement. INTEL i960 Series with subsequent ARM in particular, a broad range of applications, quickly replaced by 32bit singlechip 16bit singlechip highend status, and enter the mainstream market. Traditional 8bit singlechip performance has been the rapid increase in processing power pared to the 8039。s close on the heels of a special processor, while the ordinary price of the model dropped to one . dollars, the most highend models, only 10 . dollars. Contemporary singlechip microputer system is no longer only the baremetal environment in the development and use of a large number of dedicated embedded operating system is widely used in the full range of singlechip microputer. In PDAs and cell phones as the core processing of highend singlechip or even a dedicated direct access to Windows and Linux operating systems. More than a dedicated singlechip processor suitable for embedded systems, so it was up to the application. In fact the number of singlechip is the world39。s shadow! ...... It is mainly as part of the core ponents of the control. It is an online realtime control puter, controlline is at the scene, we need to have a stronger antiinterference ability, low cost, and this is offline puter (such as home PC) The main difference. By singlechip process, and can be amended. Through different procedures to achieve different functions, in particular the special unique features, this is the need to charge other devices can do a great effort, some of it is also difficult to make great efforts to do so. A function is not very plicated if the United States the development of the 5039。s series of singlechip market, the result will be different! Simply because the adoption of singlechip preparation process you can achieve high intelligence, high efficiency and high reliability! Because of the cost of singlechip is sensitive, so the dominant software or the lowest level assembly language, which is in addition to the lowest level for more than binary machine code of the language, since such a lowlevel so why should we use? Many of the senior39。s hard drive is nothing, but in terms of the singlechip microputer is unacceptable. Singlechip in the utilization of hardware resources have to do very high, so the pilation of the original while still in heavy use. The same token, if the puter gian