【正文】 8 個(gè)位，即每行由 16 字節(jié)，共 16 8=128 個(gè)點(diǎn)組成，屏上 64 16 個(gè)顯示單元和顯示 RAM 區(qū) 1024 個(gè)字節(jié)相對(duì)應(yīng)，每一字節(jié)的內(nèi)容和屏上相應(yīng)位置的亮暗對(duì)應(yīng)?；鶞?zhǔn)電壓，基準(zhǔn)電壓的輸入必須對(duì)于模擬公共端 COM是正電壓。 ⑦ 位驅(qū)動(dòng)信號(hào) D D D D D1（ 1 1 1 1 20 腳）每一位驅(qū)動(dòng)信號(hào)分別輸出一個(gè)正脈沖信號(hào)，脈沖寬度為 200 個(gè)時(shí)鐘周期，其中 D5 對(duì)應(yīng)萬位選通，以下依次為千、百、十、個(gè)位。 ④ OR（ 27腳）當(dāng)輸入電壓超出量程范圍（ 20220）， OR將會(huì)變高。注意：第一次轉(zhuǎn)換周期中的 AZ階段時(shí)間為 900110001個(gè)時(shí)鐘脈沖，這是由于啟動(dòng)脈沖和內(nèi)部計(jì)數(shù)器狀態(tài)不同步造成的。 ⑨ 采用 28外引線雙列直插式封裝，外引線功能端排列如圖所示 。能在但極性參考電壓下對(duì)雙極性模擬輸入電壓進(jìn)行 A/D轉(zhuǎn)換，模 擬電壓的范圍為 0～177。 雙積 A/D 轉(zhuǎn)換器的工作原理 圖 A/D 轉(zhuǎn)換器 如圖所示：對(duì)輸入模擬電壓和基準(zhǔn)電壓進(jìn)行兩次積分，先對(duì)輸入模擬電壓進(jìn)行積分，將其變換成 與輸入模擬電壓成正比的時(shí)間間隔 T1，再利用計(jì)數(shù)器測出此時(shí)間間隔，則計(jì)數(shù)器所 5 計(jì)的數(shù)字量就正比于輸入的模擬電壓；接著對(duì)基準(zhǔn)電壓進(jìn)行同樣的處理。智能化數(shù)字溫度計(jì)所采用的單片雙積分型 ADC芯片 ICL7135，它要求輸入電壓 0177。傳統(tǒng)的溫度計(jì)功能單一、精度低，不能滿足數(shù)字化時(shí)代的需求，采用單片機(jī)的數(shù)字溫度計(jì)，由于精度高、抗干擾能力強(qiáng)，可擴(kuò)展性強(qiáng)、集成方便得到了廣泛的應(yīng)用。 關(guān)鍵詞： 溫度測量， DS18B20 2 Abstract : The introduction of a costbased AT89C2051 MCU a temperatur measurement circuits, the circuits used DS18B20 highprecision temperatur sensor , measuring scope 55℃ ～ +125℃ ,can use the keybord set the warning limitation, the use of four bits seven segments LED that can be display the current temperature. The paper focuses on providing a software and hardware system ponents circuit, introduced the theory of DS18B20, the founctions and applications of AT89C2051 .This circuit design innovative, powerful, can be expansionary strong. Key Words : Temperatur measurement, DS18B20 3 傳感器部分 AT89C2051單片機(jī) LED 顯示 設(shè)置報(bào)警鍵盤 報(bào)警揚(yáng)聲器 1 前言 數(shù)字溫度計(jì)（ Digital Thermometer）簡稱 DTM，它是采用數(shù)字化測量技術(shù)，把連續(xù)的溫度值轉(zhuǎn)換成不連續(xù)、離散的數(shù)字形式并加以顯示的儀表。 圖 3 硬件設(shè)計(jì) 輸入電路 圖 圖 4 輸入電路的作用是把不同量程的被測的電壓規(guī)范到 A/D 轉(zhuǎn)換器所要求的電壓值。在對(duì)轉(zhuǎn)換精度要求較高，而對(duì)轉(zhuǎn)換速度 要求不高的場合如電壓測量有廣泛的應(yīng)用。 ③ 具有自動(dòng)極性轉(zhuǎn)換功能 。 ⑧ 對(duì)外提供六個(gè)輸入 ,輸出控制信號(hào) (R/H,BUSH,ST,POL,OR,UR),因此除用于數(shù)字溫度計(jì)外 ,還能與異步接收 /發(fā)送器 ,微處理器或其它控制電路連接使用。若把R/H端用作啟動(dòng)功能時(shí)，只要在該端輸入一個(gè)正脈沖（寬度≥300 ns），轉(zhuǎn)換器就從 AZ 階段開始進(jìn)行 A/D 轉(zhuǎn)換。因此利用 BUSY 功能，可以實(shí)現(xiàn) A/D 轉(zhuǎn)換結(jié)果的遠(yuǎn)距離雙線傳送，其還原方法是將 BUSY和 CLK“ 與 ” 后來計(jì)數(shù)器，再減去 10001就可得到原來的轉(zhuǎn)換結(jié)果。該信號(hào) DE 階段開始時(shí)變化，并維持一個(gè) A/D 轉(zhuǎn)換調(diào)期。 最后還要說明一點(diǎn)，由于數(shù)字部分以 DGNG 端作為接地端，所以所有輸出端輸出電平以 DGNG 作為相對(duì)參考點(diǎn)。 液晶顯示部分 顯示接口用來顯示系統(tǒng)的狀態(tài)，命令或采集的電壓數(shù)據(jù)。其中 E是下降沿觸發(fā)的片選信號(hào)， R/W是讀寫信號(hào)， RS 是寄存器選擇信號(hào)本模塊設(shè)計(jì)要點(diǎn)如下：顯示模塊初始化：首先清屏，再設(shè)置接口數(shù)據(jù)位為 8 位，顯示行數(shù)為 1 行，字型為 5 7點(diǎn)陣，然后 設(shè) 置為整體顯示，取消光標(biāo)和字體閃爍 ,最后設(shè)置為正向增量方式且不移位。緊接著LCDM1601B進(jìn)行一次清屏，使其各個(gè)指令、數(shù)據(jù)寄存器的值進(jìn)行清空，屏幕不顯示任何字符。每次向 LCDM 中寫入一個(gè)指令，就調(diào)用一次 ENABLE，然后再對(duì)顯示器進(jìn)行閃爍、光標(biāo)等功能進(jìn)行設(shè)定。 A/D 中斷程序設(shè)計(jì) 圖 數(shù)據(jù)地址 15 ICL7135每一分鐘完成 3次據(jù)的采集工作， 1/3秒完成后向 CPU申請(qǐng)中斷 ,CPU這時(shí)暫停工作，為中斷服務(wù) .中斷響應(yīng)后關(guān)中斷，將 PSW、 ACC壓棧，判斷是否首圖 中斷子程序流程圖 16 次中斷，如果是首次中斷，則將正負(fù)號(hào)標(biāo)志位置入 60H，再把萬位置入 61H中，如果 不是首次中斷，則跳到 NEXT 處，如果是第二次中斷，則將千位數(shù)置入 62H中，如果是第三次中斷，再將百位數(shù)置入 63H 中，第四次中斷則將十位數(shù)置入64H中，第五次中斷則將小數(shù)點(diǎn)位置入 65H中，同時(shí)個(gè)位置入 66H中。這個(gè)通信口既可以用于網(wǎng)絡(luò)通信，亦可實(shí)現(xiàn)串行異步通信，還可以構(gòu)成同步移位寄存器使用。數(shù)據(jù)通過 TXD輸出，在 8個(gè)位輸出完畢后， SCON寄存器的 TI位被設(shè)為 1， CPU只要判斷 TI是 1，接著發(fā)送下一個(gè)字節(jié)。李老師愛崗敬業(yè)，治學(xué)嚴(yán)謹(jǐn)，思維嚴(yán)密，平易近人是我十分尊敬的老師，在此對(duì)他表示感謝。 當(dāng)我把我的想法告訴我的同學(xué)時(shí)，他們沒有一個(gè)相信我會(huì)做成。 調(diào)試程序時(shí)，我遇到了很多困難，例如：參考文獻(xiàn)錯(cuò)誤的誤導(dǎo)，調(diào)試環(huán)境的錯(cuò)誤使用， 硬件改裝，程序本身不可預(yù)見的錯(cuò)誤等。 。t just about sharing art with nomadic families but also about gaining inspiration for the music and dance. Ulan Muqir literally translates as red burgeon, and today39。s to e and recapping the key points. This device, not used in the original, is culturally understandable but artistically mediocre. What puzzles me is the two new songs for the opening and end credits. They were written in English, but sung by Chinese with an unfortable accent. They were obviously designed to appeal to an Englishspeaking base, but do not jibe with the Chinese dialogue. Speaking of the dialogue, the English translation, picked apart by some Chinese, is too literal for my taste. I can imagine a typical American hit by a flurry of royal ranks, addresses and greetings, even multiple names and titles for the same person. The first half hour must be a swamp to wade through, very much like my experience of getting through a Tolstoy tome with its endless inflections of names transliterated into lengthy Chinese. I see the choice of verbatim translation as an effort for conveying exotica. It is fairly petent, with no error that I could detect, but fails to rise above words or capture the essence of the language. A cultural product usually crosses over to a foreign territory first by an emphasis on the monalities. But whether inside or outside China, the temptation to sell it for the differences is just too great. Sure, the sumptuous sets and costumes are a big attraction, but the narrative technique has bee－ how shall I put it?－ a bit anglicized, which is necessary for cultural export. Judging by the responses, this legend, which, contrary to the claim of the English trailer, is totally fictitious, has departed from China but not yet landed on American shores. I am a big fan of Ralph Waldo Emerson39。 names and figuring out what to do with them for the brief time each week that I stand in front of them. I do not consider the challenges of learning to live here part of a purposeful life. I consider those issues existential in nature. One of the problems with my life in America was that I felt it had no purpose. I went to work every day and even did what I could to make my colleagues