【正文】 what would cause a harmless flash on the screen of a television set could lead to a serious error in a puter.As far as puting circuits were concerned, we found ourselves with an embrace rich. For example, we could use vacuum tube diodes for gates as we did in the EDSAC or pentodes with control signals on both grids, a system widely used elsewhere. This sort of choice persisted and the term families of logic came into use. Those who have worked in the puter field will remember TTL, ECL and CMOS. Of these, CMOS has now bee dominant.In those early years, the IEE was still dominated by power engineering and we had to fight a number of major battles in order to get radio engineering along with the rapidly developing subject of electric. Dubbed in the IEE light current electrical engineering. properly recognized as an activity in its own right. I remember that we had some difficulty in organizing a conference because the power engineers’ ways of doing things were not our ways. A minor source of irritation was that all IEE published papers were expected to start with a lengthy statement of earlier practice, something difficult to do when there was no earlier practiceConsolidation in the 1960s By the late 50s or early 1960s, the heroic pioneering stage was over and the puter field was starting up in real earnest. The number of puters in the world had increased and they were much more reliable than the very early ones. To those years we can ascribe the first steps in high level languages and the first operating systems. Experimental timesharing was beginning, and ultimately puter graphics was to e along.Above all, transistors began to replace vacuum tubes. This change presented a formidable challenge to the engineers of the day. They had to forget what they knew about circuits and start again. It can only be said that they measured up superbly well to the challenge and that the change could not have gone more smoothly. Soon it was found possible to put more than one transistor on the same bit of silicon, and this was the beginning of integrated circuits. As time went on, a sufficient level of integration was reached for one chip to acmodate enough transistors for a small number of gates or flip flops. This led to a range of chips known as the 7400 series. The gates and flip flops were independent of one another and each had its own pins. They could be connected by offchip wiring to make a puter or anything else.These chips made a new kind of puter possible. It was called a miniputer. It was something less that a mainframe, but still very powerful, and much more affordable. Instead of having one expensive mainframe for the whole organization, a business or a university was able to have a miniputer for each major department.Before long miniputers began to spread and bee more powerful. The world was hungry for puting power and it had been very frustrating for industry not to be able to supply it on the scale required and at a reasonable cost. Miniputers transformed the situation.The fall in the cost of puting did not start with the miniputer。4個250次沒完循環(huán)RET。多加的DJNZ R1,DPLOP 。顯示1MSSETB JC XSW。送出十位的7段代碼CLR 。取十位數(shù)MOVC A,A+DPTR 。開個位顯示ACALL D1MS 。查個位數(shù)的7段代碼MOV P0,A 。顯示1000次DPLOP:MOV DPTR,NUMTAB1MOV A,A_BIT 。個位在BMOV R0,4 CLR C。10進制/10=10進制DIV ABMOV B_BIT,A 。 低位存入29H(TEMPER_L),高位存入28H(TEMPER_H)RE00:MOV R2,8。 讀DS18B20的程序,從DS18B20中讀出兩個字節(jié)的溫度數(shù)據(jù) READ_18200:MOV R4,2 。寫DS18B20的子程序(有具體的時序要求)WRITE_1820:MOV R2,8。 發(fā)出讀溫度命令LCALL WRITE_1820LCALL READ_18200。準備讀溫度前先復(fù)位MOV A,0CCH 。 發(fā)出溫度轉(zhuǎn)換命令LCALL WRITE_1820。 判斷DS1820是否存在?若DS18B20不存在則返回TSS2:MOV A,0CCH 。 讀出轉(zhuǎn)換后的溫度值GET_TEMPER:SETB LCALL INIT_1820。 清標志位,表示DS1820不存在LJMP TSR7TSR5:MOV R0,117TSR6:DJNZ R0,TSR6 。 延時TSR3:SETB FLAG1 。然后拉高數(shù)據(jù)線NOPNOPNOPMOV R0,25HTSR2:JNB ,TSR3。 這是DS18B20復(fù)位初始化子程序INIT_1820:SETB NOPCLR 。將28H中的最低位移入CRRC AMOV C,41HRRC AMOV C,42HRRC AMOV C,43HRRC AMOV 29H,ALCALL DISPLAY。數(shù)碼管十位數(shù)存放內(nèi)存位置XS EQU 30H MOV A,00H MOV P2,A MAIN:LCALL GET_TEMPER。是否檢測到DS18B20標志位 A_BIT EQU 20H 。同時也感謝學(xué)院為我提供良好的做畢業(yè)設(shè)計的環(huán)境。在此，學(xué)生對您表示衷心的感謝。在論文開始的初期，我對于論文的結(jié)構(gòu)以及文獻選取等方面都有很多問題，在胡老師的悉心指導(dǎo)下，我漸漸地在資料查詢、開題、研究以及撰寫的每一個環(huán)節(jié)都有了明確的方向。參考文獻[1] 佟云峰．單片機原理及其應(yīng)用[M]．重慶大學(xué)出版社．2004．[2] 辜小兵．韓光勇．單片機與基礎(chǔ)應(yīng)用[M]．重慶大學(xué)出版社．2010．[3] 曹龍漢．MCS51單片機原理及應(yīng)用[M]．重慶大學(xué)出版社．2004．[4] 金偉正．單線數(shù)字溫度傳感器的原理與應(yīng)用[J]．2000．[5] 陳躍東．DS18B20集成溫度傳感器原理與應(yīng)用[J]．2002．[6] 李朝青．單片機原理及接口技術(shù)[M]．北京航空航天大學(xué)出版社．2011．[7] 趙負圖．現(xiàn)代傳感器集成電路[M]．人民郵電出版社．2000．[8] 何立民．單片機高級教程:應(yīng)用與設(shè)計(第2版)[M]．北京航天航空大學(xué)出版社．2007．[9] 趙蓉．傳感器技術(shù)及應(yīng)用[M]．高等教育出版社．2010． [10] 楊忠輝，黃博?。畣涡酒?051務(wù)實與應(yīng)用[M]．中國水利水電版社．.[11] 宋亞偉，李恒宗．基于DS18B20的溫度測量系統(tǒng)[J]．機電工程技術(shù)．．[12] 趙永杰，徐源．溫室測試系統(tǒng)的設(shè)計與實現(xiàn)[J]．現(xiàn)代電子技術(shù)．．[13] 周月霞，孫傳友．DS18B20硬件連接及軟件編程[J]．傳感器世界．．[14] 陳妙芳，胡曉東．基于AT89S51單片機的溫度控制系統(tǒng)設(shè)計[J]．機械工程師．[15] 胡朝．基于單片機的溫度控制系統(tǒng)的開發(fā)與應(yīng)用[J]．商場現(xiàn)代化．．[16] 李玉峰．MCS51系列單片機原理與接口技術(shù)[M]．人民郵電出版社．2004．[17] 王忠飛．MCS51單片機原理及嵌入式系統(tǒng)應(yīng)用[M]．西安電子科技大學(xué)出版社．2009．[18] 趙剛，于珍珠．基于51單片機的溫度測量系統(tǒng)[J]．微計算機信息．. [19] 王福瑞．單片微機測控系統(tǒng)設(shè)計大全[M]．電子工業(yè)出版社．2006．[20] Maurice Wilkes．Process in Computers[R]．Prestige Lecture of Cambridge．.致 謝畢業(yè)設(shè)計完成了，在這個過程中我學(xué)到了很多東西。使得產(chǎn)品的生產(chǎn)成本降低，從而使系統(tǒng)的使用者獲得的利潤提高了。這對于提高系統(tǒng)的利用率，避免重復(fù)設(shè)計有很大的幫助的。對于本系統(tǒng)的使用者來說，本系統(tǒng)能夠很穩(wěn)定的控制溫度而且穩(wěn)定性很高。本系統(tǒng)的設(shè)計，是為了保證某特定環(huán)境溫度維持在設(shè)定的范圍內(nèi)，以保證工作系統(tǒng)在穩(wěn)定的狀態(tài)下工作。本系統(tǒng)的設(shè)計成功知識實現(xiàn)自動控制的“冰山一角”，但它為以后更加智能化、人性化的自動控制系統(tǒng)的設(shè)計，作了鋪墊。根據(jù)我國的科技和工業(yè)水平，這個系統(tǒng)的設(shè)計是符合工業(yè)生產(chǎn)的需要。在單片機自動控制已經(jīng)廣泛的應(yīng)用于人們的生產(chǎn)和生活的今天，傳統(tǒng)用模擬電路來控制溫度的做法，已經(jīng)逐漸被淘汰。：開 始結(jié) 束串行口初始化往緩沖區(qū)送數(shù)查段碼送顯示 動態(tài)顯示子程序 第六節(jié) 控制執(zhí)行子程序流程圖控制執(zhí)行程序是本系統(tǒng)的核心，是實現(xiàn)溫度自動控制過程中的最主要步驟。DS18B20的各個命令對時序的要求特別嚴格，所以必須按照所要求的時序才能達到預(yù)期的目的，同時，要注意讀進來的是高位在后低位在前， 共有12位數(shù)，小數(shù)4位，整數(shù)7位，還有一位符號位。： 主程序流程圖 第三節(jié) 數(shù)據(jù)轉(zhuǎn)換子程序流程圖溫度傳感器采集到的模擬信號，需經(jīng)過A/D轉(zhuǎn)換器轉(zhuǎn)為數(shù)字信號后交由單片機處理。第二節(jié) 系統(tǒng)主程序流程圖主程序的主要功能是負責(zé)溫度的實時顯示、讀出并處理DS18B20的測量的當(dāng)前溫度值，溫度測量每1s進行一次，這樣可以在一秒之內(nèi)測量一次被測溫度。對于要求反應(yīng)靈敏與控制及時的工控、檢測等實時控制系統(tǒng)以及要求體積小、系統(tǒng)小的許多“電腦化”產(chǎn)品，可以充分體現(xiàn)出匯編語言簡明、整齊、執(zhí)行時間短和易于使用的特點[8]。MCS—51指令系統(tǒng)的指令長度較短，它在存儲空間和執(zhí)行時間方面具有較高的效率，編成的程序占用內(nèi)存單元少，執(zhí)行也非常的快捷，與本系統(tǒng)的應(yīng)用要求很適合。原因在于，本系統(tǒng)是編制程序工作量不大、規(guī)模較小的單片機微控制系統(tǒng)，使用匯編語言可以不用像高級語言那樣占用較多的存儲空間，