【正文】 一個(gè)點(diǎn)或一個(gè)筆畫(huà)發(fā)亮，控制不同組合的二極管導(dǎo)通，就能顯示出各種字符，常用的LED數(shù)碼管有7段和“米”字段之分。三、溫度傳感器的選擇智能溫度傳感器(亦稱數(shù)字溫度傳感器)是微電子技術(shù)、計(jì)算機(jī)技術(shù)和自動(dòng)測(cè)試技術(shù)(ATE)的結(jié)晶。典型產(chǎn)品有DS18B20，智能溫度控制器適配各種微控制器，構(gòu)成智能化溫控系統(tǒng)。現(xiàn)場(chǎng)溫度直接以“一線總線”的數(shù)字方式傳輸，大大提高了系統(tǒng)的抗干擾性。 由于DS18B20將溫度傳感器、信號(hào)放大調(diào)理、A/D轉(zhuǎn)換、接口全部集成于一芯片，與單片機(jī)連接簡(jiǎn)單、方便，與AD590相比是更新一代的溫度傳感器，所以溫度傳感器采用DS18B20。頭2個(gè)字節(jié)包含測(cè)得的溫度信息，第3和第4字節(jié)TH和TL的拷貝，是易失的，每次上電復(fù)位時(shí)被刷新。TL 低溫寄存器Byte4配位寄存器223。接著主機(jī)釋放總線，延時(shí)15～60us，并進(jìn)入接受模式，以產(chǎn)生低電平應(yīng)答脈沖，若為低電平，再延時(shí)480us。主機(jī)在讀時(shí)序期間必須釋放總線，并且在時(shí)序起始后的15us之內(nèi)采樣總線狀態(tài)。讀暫存器0BEH讀內(nèi)部RAM中9字節(jié)的內(nèi)容。用于產(chǎn)生固定頻率的脈沖信號(hào)送給減法計(jì)數(shù)器1，高溫度系數(shù)晶振隨溫度變化其震蕩頻率明顯改變，所產(chǎn)生的信號(hào)作為減法計(jì)數(shù)器2的脈沖輸入，圖中還隱含著計(jì)數(shù)門(mén)，當(dāng)計(jì)數(shù)門(mén)打開(kāi)時(shí)，DS18B20就對(duì)低溫度系數(shù)振蕩器產(chǎn)生的時(shí)鐘脈沖后進(jìn)行計(jì)數(shù)，進(jìn)而完成溫度測(cè)量。初始化DS18B20跳過(guò)ROM匹配溫度變換延時(shí)1S跳過(guò)ROM匹配讀暫存器轉(zhuǎn)換成顯示碼數(shù)碼管顯示 DS18B20測(cè)溫流程第四節(jié) 人機(jī)交互與串口通信一、 人機(jī)交互人機(jī)交互、人機(jī)互動(dòng)（英文：Human–Computer Interaction或Human–Machine Interaction，簡(jiǎn)稱HCI或HMI），是一門(mén)研究系統(tǒng)與用戶之間的交互關(guān)系的學(xué)問(wèn)?？晒┤藱C(jī)交互使用的設(shè)備主要有鍵盤(pán)顯示、鼠標(biāo)、各種模式識(shí)別設(shè)備等。此外，通過(guò)圖形進(jìn)行人機(jī)交互也吸引著人們?nèi)ミM(jìn)行研究。對(duì)于那些與計(jì)算機(jī)相距不遠(yuǎn)的人機(jī)交換設(shè)備和串行存儲(chǔ)的外部設(shè)備如終端、打印機(jī)、邏輯分析儀、磁盤(pán)等，采用串行方式交換數(shù)據(jù)也很普遍。在數(shù)據(jù)輸出過(guò)程中，CPU 把要輸出的字符（并行地）送入“數(shù)據(jù)輸出寄存器”，“數(shù)據(jù)輸出寄存器”的內(nèi)容傳輸?shù)健鞍l(fā)送移位寄存器”，然后由“發(fā)送移位寄存器”移位，把數(shù)據(jù) 1 位 1 位地送到外設(shè)。在面向字符的同步方式下，接口要在待傳送的數(shù)據(jù)塊前加上同步字符。⑥提供EIARS232C接口標(biāo)準(zhǔn)所要求的信號(hào)線：遠(yuǎn)距離通信采用MODEM時(shí)，需要9根信號(hào)線；近距離零MODEM方式，只需要3根信號(hào)線。檢測(cè)范圍5攝氏度到60攝氏度。當(dāng)確認(rèn)有按鍵按下后下一步就要識(shí)別哪一個(gè)按鍵按下。： 鍵盤(pán)的按鍵分布0123456789F1F2清除開(kāi)啟關(guān)閉確定鍵盤(pán)共有16個(gè)按鍵，用于方便設(shè)定溫度。機(jī)器語(yǔ)言是機(jī)器唯一能“懂”的語(yǔ)言，用匯編語(yǔ)言或高級(jí)語(yǔ)言編寫(xiě)的程序（稱為源程序）最終都必須翻譯成機(jī)器語(yǔ)言的程序（成為目標(biāo)程序），計(jì)算機(jī)才能“看懂”，然后逐一執(zhí)行。第二節(jié) 系統(tǒng)主程序流程圖主程序的主要功能是負(fù)責(zé)溫度的實(shí)時(shí)顯示、讀出并處理DS18B20的測(cè)量的當(dāng)前溫度值，溫度測(cè)量每1s進(jìn)行一次，這樣可以在一秒之內(nèi)測(cè)量一次被測(cè)溫度。在單片機(jī)自動(dòng)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(lái)控制溫度的做法，已經(jīng)逐漸被淘汰。對(duì)于本系統(tǒng)的使用者來(lái)說(shuō)，本系統(tǒng)能夠很穩(wěn)定的控制溫度而且穩(wěn)定性很高。在論文開(kāi)始的初期，我對(duì)于論文的結(jié)構(gòu)以及文獻(xiàn)選取等方面都有很多問(wèn)題，在胡老師的悉心指導(dǎo)下，我漸漸地在資料查詢、開(kāi)題、研究以及撰寫(xiě)的每一個(gè)環(huán)節(jié)都有了明確的方向。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。 延時(shí)TSR3:SETB FLAG1 。 發(fā)出溫度轉(zhuǎn)換命令LCALL WRITE_1820。 讀DS18B20的程序,從DS18B20中讀出兩個(gè)字節(jié)的溫度數(shù)據(jù) READ_18200:MOV R4,2 。顯示1000次DPLOP:MOV DPTR,NUMTAB1MOV A,A_BIT 。送出十位的7段代碼CLR 。 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。顯示1MSSETB JC XSW。查個(gè)位數(shù)的7段代碼MOV P0,A 。 低位存入29H(TEMPER_L),高位存入28H(TEMPER_H)RE00:MOV R2,8。準(zhǔn)備讀溫度前先復(fù)位MOV A,0CCH 。 清標(biāo)志位,表示DS1820不存在LJMP TSR7TSR5:MOV R0,117TSR6:DJNZ R0,TSR6 。將28H中的最低位移入CRRC AMOV C,41HRRC AMOV C,42HRRC AMOV C,43HRRC AMOV 29H,ALCALL DISPLAY。在此，學(xué)生對(duì)您表示衷心的感謝。這對(duì)于提高系統(tǒng)的利用率，避免重復(fù)設(shè)計(jì)有很大的幫助的。根據(jù)我國(guó)的科技和工業(yè)水平，這個(gè)系統(tǒng)的設(shè)計(jì)是符合工業(yè)生產(chǎn)的需要。： 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(hào)，需經(jīng)過(guò)A/D轉(zhuǎn)換器轉(zhuǎn)為數(shù)字信號(hào)后交由單片機(jī)處理。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(jī)微控制系統(tǒng)，使用匯編語(yǔ)言可以不用像高級(jí)語(yǔ)言那樣占用較多的存儲(chǔ)空間，適合于存儲(chǔ)容量較小的系統(tǒng)。當(dāng)由于環(huán)境溫度變化太劇烈或由于加熱或降溫設(shè)備出現(xiàn)故障，或者溫度傳感頭出現(xiàn)故障導(dǎo)致在一段時(shí)間內(nèi)不能將環(huán)境溫度調(diào)整到規(guī)定的溫度限內(nèi)的時(shí)候，單片機(jī)通過(guò)三極管驅(qū)動(dòng)揚(yáng)聲器發(fā)出警笛聲。*4鍵盤(pán)，說(shuō)明線反轉(zhuǎn)法工作原理。第二節(jié) 人機(jī)交互與串口通信單元設(shè)計(jì)一、 輸入電路設(shè)計(jì)（一）單片機(jī)電路： 單片機(jī)電路引腳圖（二）溫度傳感器電路： 溫度傳感器電路引腳圖二、 顯示電路設(shè)計(jì)顯示電路采用了7段共陰數(shù)碼管掃描電路，節(jié)約了單片機(jī)的輸出端口，便于程序的編寫(xiě)。（理論性強(qiáng)）第三章 系統(tǒng)硬件電路設(shè)計(jì)第一節(jié) 系統(tǒng)結(jié)構(gòu)框圖溫度控制系統(tǒng)采用AT89S51八位機(jī)作為微處理單元進(jìn)行控制。所以當(dāng)數(shù)據(jù)由計(jì)算機(jī)送至數(shù)據(jù)發(fā)送器時(shí)，首先把串行數(shù)據(jù)轉(zhuǎn)換為并行數(shù)才能送入計(jì)算機(jī)處理。接口中的“控制寄存器”用來(lái)容納 CPU 送給此接口的各種控制信息，這些控制信息決定接口的工作方式。所以串行接口是微機(jī)應(yīng)用系統(tǒng)常用的接口?許多外設(shè)和計(jì)算機(jī)按串行方式進(jìn)行通信，這里所說(shuō)的串行方式，是指外設(shè)與接口電路之間的信息傳送方式，實(shí)際上，C