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ll be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. It will be like he is diving into the shallow end. Skydiver preps for the big jumpWhen he jumps, he is expected to reach the speed of sound 690 mph (1,110 kph) in less than 40 seconds. Like hitting the top of the water, he will begin to slow as he approaches the more dense air closer to Earth. But this will not be enough to stop him pletely.If he goes too fast or spins out of control, he has a stabilization parachute that can be deployed to slow him down. His team hopes it39。 Have declared the end of the encounter that haven39。那些曾經(jīng)所謂的非做不可,只是青蔥年華里自己給自己注射的一支強(qiáng)心劑,或者說,是自以為是的精神寄托罷了。s time, your ideas are always special to clear. Want, want, line is clear, as if nothing could shake his. Also once seemed to be determined to do something, but more often is he backed out at last. Dislike his cowardice, finally found that there are a lot of love, there are a lot of miss, like shadow really have been doomed. Those who do, just green years oneself give oneself an arm injection, or is a selfrighteous spiritual. 一個(gè)人的時(shí)候,自己的想法總是特別地清晰。t want to give vent to out your inner voice can be in the high school children of the feelings in a period, but was eventually infarction when graduation party in the throat, later again stood on the pitch he has sweat profusely, looked at his thrown a basketball hoops, suddenly found himself has already can39。The end of our life, and can meet many things really do? 而窮盡我們的一生,又能遇到多少事情是真正地非做不可?During my childhood, think lucky money and new clothes are necessary for New Year, but as the advance of the age, will be more and more found that those things are optional。 May be back in the past, to oneself the paranoid weird belief disillusionment, these days, my mind has been very messy, in my mind constantly. Always feel oneself should go to do something, or write something. Twenty years of life trajectory deeply shallow, suddenly feel something, do it. 一字開頭的年齡已經(jīng)到了尾聲。s 21 win.Michel Platini, president of European football39。s about how he felt and I would like to speak to him first to find out what his experience was.Uefa hasEmployment tribunals.The (lack of) air up there Watch mCayman Islandsbased Webb, the head of Fifa39。a damagesbased agreement, you should make sure you39。Further help.If you are being represented by a solicitor at the tribunal, they may ask you to sign an agreement where you pay their fee out of your pensation if you win the case. This is known as at you don39。START1MOVMOVDELAYSP,60HJD:延時(shí)子程序2DJNZR7,0FFH。SIMPLCALL輸出2khz方波2khz持續(xù)時(shí)間DJNZD5ms。DIV1:MOV JB FLAG1 ,KEY_FUN 。檢查有沒有按鍵按下 JNZ LK1 AJMP CH_KEY LK1:LCALL T12MS ACALL KS JNZ LK2 RET LK2:NOP LCALL SBIE 。調(diào)用數(shù)碼管顯示子程序RET 鍵盤子程序: START:NOP 。 。 。 。 。CLR DS18DQ MOV R1,DS18SL讀時(shí)序,最少60USDJNZ R5,DS18JXRD2MOV R1,AINC R1DJNZ R4,DS18JXRD3SETB DS18DQRET。 。 。 。讀取CODE 64位 。初始化CLR DS18DQCLR DS18DQMOV R7,5DJNZ R7,$ 。 。寫DS18B20的子程序(有具體的時(shí)序要求)WRITE_1820:轉(zhuǎn)換指定的DS18B20的溫度LCALL MRRDTEDP 。JB ,EXIT7MOV 33H,00HEXIT7: RETGET_TEMPER: 。十位存入32H中MOV B,10 。34H中存入溫度值的整數(shù)部分MOV B,10DIV ABMOV 31H,B 。將DS18SL的高四位右移四位,存入34H中(溫度值)MOV A,B 。延時(shí),500US低MCMOV R7,250DJNZ R7,$MOV R7,150DJNZ R7,$SETB DS18DQDS18CD1DS18CD8暫存64位ROMDS18CD2 EQU 43H 。是否檢測(cè)到DS18B20標(biāo)志位A_BIT1 EQU 31H ??驁D表示:系統(tǒng)開始工作,直至工作結(jié)束,關(guān)閉電源按F1或F2進(jìn)行溫度點(diǎn)1或溫度點(diǎn)2的設(shè)定確認(rèn)溫度控制箱上的開關(guān)全部打到關(guān)的狀態(tài)接上溫度芯片,連接好電路,接上電源,打開開關(guān) 附錄B:程序清單主程序:ORG 0000H 。從而達(dá)到控制溫度的作用。附錄A:使用說明將溫度控制箱上的開關(guān)全部打到“關(guān)”的位置將溫度芯片插到溫度控制箱的指定位置用串口線將溫度控制箱與計(jì)算機(jī)相連,打開相應(yīng)的應(yīng)用程序?qū)⒂秒娖鞯牟孱^插到溫度控制箱的插座接上溫度控制箱的電源、并打開開關(guān)。在這里尤其要感謝劉建林老師,從論文題目的選定到論文寫作的指導(dǎo),經(jīng)由您悉心的點(diǎn)撥,再經(jīng)思考后的領(lǐng)悟,常常讓我有“山重水復(fù)疑無路,柳暗花明又一村”。在這三年的求學(xué)生涯中師長、親友給與了我大力支持,在這個(gè)翠綠的季節(jié)我將邁開腳步走向遠(yuǎn)方,懷念,思索,長長的問號(hào)一個(gè)個(gè)在求學(xué)的路途中被知識(shí)的舉手擊碎,而人生的思考才剛剛開始。隨著插入插座的電器的不同,可以實(shí)現(xiàn)許多其它功能的電路。本系統(tǒng)的測(cè)溫范圍為10℃~40℃,溫度檢測(cè)系統(tǒng)根據(jù)用戶設(shè)定的溫度范圍完成一定范圍的溫度控制。 結(jié) 論測(cè)試結(jié)果設(shè)定溫度由0攝氏度到40攝氏度標(biāo)定溫差=1攝氏度 調(diào)節(jié)時(shí)間 15s(具體視現(xiàn)場(chǎng)情況)靜態(tài)誤差= 最大超調(diào)量1攝氏度通過測(cè)試分析,對(duì)于實(shí)際室內(nèi)的溫度控制,可以再提出以下 2 點(diǎn)方法 :Ⅰ增加傳感器個(gè)數(shù),對(duì)各個(gè)溫度傳感器采集的數(shù)據(jù)進(jìn)行求算術(shù)平均,可得到較為準(zhǔn)確的溫度值。有按鍵按下的時(shí)候進(jìn)入按鍵處理程序。圖71程序結(jié)構(gòu)圖程序開始的時(shí)候先設(shè)置初始化,然后就控制數(shù)碼管顯示當(dāng)前溫度。鍵盤掃描電路及按鍵處理程序:實(shí)現(xiàn)鍵盤的輸入按鍵的識(shí)別及進(jìn)入相應(yīng)的程序。需通過低通濾波電路濾波,使輸出電壓平滑。其主要原理是把單相交流電經(jīng) 過電源變壓器、整流電路、濾波電路、穩(wěn)壓電路轉(zhuǎn)換成穩(wěn)定的直流電壓。30V輸入電平低電源電流:典型值是8mA符合甚至優(yōu)于ANSI標(biāo)準(zhǔn) EIA/ESD保護(hù)大于MILSTD883(方 法3015)標(biāo)準(zhǔn)的2000V5 1單片機(jī)有一個(gè)全雙工的串行通訊口,所以單片機(jī)和電腦之間可以方便地進(jìn)行串口通訊。由于電腦串口rs232電平是10v +10v,而一般的單片機(jī)應(yīng)用系統(tǒng)的信號(hào)電壓是ttl電平0 +5v,max232就是用來進(jìn)行電平轉(zhuǎn)換的,該器件包含2驅(qū)動(dòng)器、2接收器和一個(gè)電壓發(fā)生器電路提供TIA/EIA232F電平。 串行數(shù)據(jù)輸入端(A,B)可控制數(shù)據(jù)。由于單片機(jī)的時(shí)鐘頻率達(dá)到12M,移位寄存器的移位速度相當(dāng)快,所以我們根本看不到數(shù)據(jù)是一位一位傳輸?shù)?。圖52 單片機(jī)控制信號(hào)其原理是:當(dāng)繼電器突然斷電時(shí),繼電器產(chǎn)生很大的反向電流。溫度慢慢升高。 圖51具體電路連接圖采用溫度芯片DS18B20。鍵盤共有16個(gè)按鍵,用于方便設(shè)定溫度。方法是:向行線輸出全掃描字00H,把全部列線置為低電平,然后將列線的電平狀態(tài)讀入累加器A中。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。看門狗定時(shí)器(WDT):WDT是為了解決CPU程序運(yùn)行時(shí)可能進(jìn)入混亂或死循環(huán)而設(shè)置,它由一個(gè)14bit計(jì)數(shù)器和看狗復(fù)位SFR(WDTRST)構(gòu)成。存儲(chǔ)器結(jié)構(gòu):MCS51單片機(jī)內(nèi)核采用程序存儲(chǔ)器和數(shù)據(jù)存儲(chǔ)器空間分開的結(jié)構(gòu),均具有64KB外部程序和數(shù)據(jù)的尋址空間。圖42為AUXR輔助寄存器。AT89S51單片機(jī)內(nèi)部構(gòu)造及功能:特殊功能寄存器:特殊功能寄存器的片內(nèi)空間分存如下圖32所示。如EA端為高電平(接Vcc端),CPU則執(zhí)行內(nèi)部程序存儲(chǔ)器中的指令。當(dāng)訪問外部數(shù)據(jù)存儲(chǔ)器,高有兩次有效的PSEN信號(hào)。如有必要,可通過對(duì)特殊功能寄存器(SFR)區(qū)中的8EH單元的D0位置位,可禁止ALE操作。WDT益出將使該引腳輸出高電平,設(shè)置SFR AUXR 的 DISRTO 位(地址8EH)可打開或關(guān)閉該功能。作輸入端口時(shí),被外部拉低的P3口將用上拉電阻輸出電流I。Flash 編程或校驗(yàn)時(shí),P2也接收高位地址和其它控制信號(hào)。表41為P1口第二功能。在Flash編程時(shí),P0口接收指令字節(jié),而在程序校驗(yàn)時(shí),輸出指令字節(jié),校驗(yàn)時(shí),要求外接上拉電阻。空閑方式停止CPU的工作,但允許RAM,定時(shí)/計(jì)數(shù)器,串行通信口及中斷系統(tǒng)繼續(xù)工作。由于系統(tǒng)控制方案簡單 ,數(shù)據(jù)量也不大 ,考慮到電路的簡單和成本等因素 ,因此在本設(shè)計(jì)中選用 A TMEL 公司的 A T89S51單片機(jī)作為主控芯片。AT89S51具有如下特點(diǎn):40個(gè)引腳,4k Bytes Flash片內(nèi)程序存儲(chǔ)器,128 bytes的隨機(jī)存取數(shù)據(jù)存儲(chǔ)器(RAM),32個(gè)外部雙向輸入/輸出(I/O)口,5個(gè)中斷優(yōu)先級(jí)2層中斷嵌套中斷,2個(gè)16位可編程定時(shí)計(jì)數(shù)器,2個(gè)全雙工串行通信口,看門狗(WDT)電路,片內(nèi)時(shí)鐘振蕩器。該芯片的物理化學(xué)性很穩(wěn)定,它能用做工業(yè)測(cè)溫元件,且此元件線形較好。 系統(tǒng)中將通過串口通訊連接PC機(jī)存儲(chǔ)溫度變化時(shí)的歷史數(shù)據(jù),以便觀察整個(gè)溫度的控制過程及監(jiān)控溫度的變化全過程。具體要求如下: 1. 溫度連續(xù)可調(diào),范圍為0℃40℃ 2. 超調(diào)量σ%≤20% 3. 溫度誤差≤177。數(shù)字溫度傳感器DS18B20只用一個(gè)引腳即可與單片機(jī)進(jìn)行通信,大大減少了接線的麻煩,使得單片機(jī)更加具有擴(kuò)展性。這類控制對(duì)象慣性大,滯后現(xiàn)象嚴(yán)重,存在很多不確定的因素,難以建立精確的數(shù)學(xué)模型,從而導(dǎo)致控制系統(tǒng)性能不佳,甚至出現(xiàn)控制不穩(wěn)定、失控現(xiàn)象。s Design AbstractThis design take at89S51 mo