畢業(yè)設(shè)計(jì)-基于單片機(jī)的溫室溫度檢測(cè)裝置設(shè)計(jì)-wenkub.com
2025-01-14 00:40 本頁(yè)面
【正文】 ll be traveling fast, so despite the distance, it will not be like diving 19 into the deep end of a pool. It will be like he is diving into the shallow end. Skydiver preps for the big jump When 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(shuō)，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(kāi)頭的年齡已經(jīng)到了尾聲。s 21 win. Michel Platini, president of European football39。s antiracism taskforce, is in London for the Football Association39。t agree with the disciplinary action your employer has taken against you ? your employer dismisses you and you think that you have been dismissed unfairly. For more information about dismissal and unfair dismissal, see Dismissal. You can make a claim to an employment tribunal, even if you haven39。數(shù)碼管顯示子程序 。讀 DS18B20 的程序 ,從第一通道 DS18B20 中讀出兩個(gè)字節(jié)的溫度數(shù)據(jù) 。本設(shè)計(jì)采用 DS18B20 數(shù)字溫度傳感器，具有線路簡(jiǎn)單、硬件少、成本低的優(yōu)點(diǎn)，應(yīng)用前景比較廣泛，尤其其具有完善的單總線通信協(xié)議，無(wú)需復(fù)雜繁瑣的布線就可以構(gòu)成多點(diǎn)溫度檢測(cè)系統(tǒng)，充分利用了 AT89C51 和 DS18B20 硬件接口電路簡(jiǎn)潔性。 表 管腳 排列說(shuō)明 符號(hào) 引腳 說(shuō)明 AD0AD7 2， 1， 2823 多路地址 /數(shù)據(jù)總線 ALE/AS 3 ALE 輸入信號(hào)， AS 輸入信號(hào) /CS 4 片選輸入，低電平訪問(wèn) SJA1000 （ /RD） /E 5 微控制器 WR 信號(hào)或 E 使能信號(hào) /WR 6 微控制器 /WR 信號(hào)或 RD 信號(hào) CLKOUT 7 SJA100 產(chǎn)生的提供給為控制的時(shí)鐘輸出信號(hào)；時(shí)鐘控制器的時(shí)鐘關(guān)閉位可禁止該引腳 Vss1 8 接地 XTAL1 9 輸入到振蕩器放大電路 XTAL2 10 振蕩放大電路輸出 MODE 11 模式選擇輸 入 VDD3 12 輸出驅(qū)動(dòng)的 5V 電壓源 TX0 13 從 CAN 輸出驅(qū)動(dòng)器 0 輸出到物理線路上 TX1 14 從 CAN 輸出驅(qū)動(dòng)器 1 到物理線路上 VSS3 15 輸出驅(qū)動(dòng)器接地 8 圖 CAN總線傳輸 電路 鍵盤電路設(shè)計(jì) 獨(dú)立式按鍵是指直接用 I/O 口線構(gòu)成的單個(gè)按鍵電路。把其余三根線和單片機(jī)的 I/ O 口相接 , 即可實(shí)現(xiàn) 。當(dāng)輸出允許控制 (EN) 為高電平時(shí) , 并行輸出 (Q0～Q7) 為高阻態(tài) , 而串行輸出 (QS) 不受影響。寄存器和鎖存器分別有各自的時(shí)鐘輸入 (SCLK 和 SLCK) , 都是上升沿有效。其溫度采集的數(shù)據(jù)由 P1 口送進(jìn)單片機(jī)進(jìn)行處理，電路原理圖如 圖 所示。圖 中電容 C3 和電阻 R2 對(duì)電源十 5V 來(lái)說(shuō)構(gòu)成微分電路。 本設(shè)計(jì)中由于使用ＣＡＮ總線的控制器 SJA1000，因此單片機(jī)的時(shí)鐘電路可以和 SJA1000 共用，在這里只畫出了單片機(jī)的時(shí)鐘電路。 圖 單片機(jī)時(shí)鐘電路 外接石英晶體（或陶瓷諧振器）及電容 C C2 接在放大器的反饋回路中構(gòu)成 5 并聯(lián)振蕩電路。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。 DS18B20 都可以設(shè)置成兩種供電方式即數(shù)據(jù)總線供電方式和外部供電方式采取數(shù)據(jù)總線供電方式可以節(jié)省一根導(dǎo)線但完 成溫度測(cè)量的時(shí)間較長(zhǎng)采取外部供電方式則多用一根導(dǎo)線但測(cè)量速度較快。 溫度 信息經(jīng)過(guò)單線接口送入 DSl8B20 或從 DS
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