【正文】 (AD1)P0.2(AD2)P0.3(AD3)(WR)P3.6(RD)P3.7XTAL2XTAL1GNDNC(A8)P2.0(A9)P2.1(A10)P2.2(A11)P2.3(A12)P2.46 5 4 3 2 144 43 42 41 40(a ) (b ) P0 口 P0 口有八條端口線，命名為 ～ ，其中 為低位， 為高位。黃燈是警告信號，面對黃燈的車輛不能越過停車線，但車輛已十分接近停車線而不能安全停車時可以進(jìn)入交叉路口。交通信號燈控制方式很多。 課程設(shè)計 (論文 ) 題 目 名 稱 基于單片機(jī)的交通燈系統(tǒng)的設(shè)計 課 程 名 稱 單片機(jī)原理及在電氣測控學(xué)科中的應(yīng)用 學(xué) 生 姓 名 學(xué) 號 系 、 專 業(yè) 電氣工程系、 09 電氣測控類 指 導(dǎo) 教 師 唐宏偉 2021 年 7 月 1 日 摘 要 本文將介紹一種基于 AT89C51 單片機(jī)設(shè)計的交通燈系統(tǒng)對于交通的控制，12 個不同顏色的發(fā)光二極管來模擬東南西北四個方向的交通的，并通過單片機(jī)寫入程序，來控制這些燈發(fā)光或者熄滅。本系統(tǒng)采用 MSC51 系列單片機(jī) 89C51 系列單片機(jī)設(shè)計交通燈控制器，實現(xiàn)了能根據(jù)實際車流量通過 89C51 芯片的 P0 口設(shè)置紅、綠燈燃亮?xí)r間的功能；紅綠燈循環(huán)點亮，倒計時剩 5 秒時黃燈閃爍警示；車輛闖紅燈報警；綠燈時間可檢測車流量并可通過雙位數(shù)碼管顯示。 方案論證與設(shè)計 整個設(shè)計以 AT89C51 單片機(jī)為核心，設(shè)計硬件如圖 圖 硬件框圖 如圖 所示，本系統(tǒng)基于 AT89C51 單片機(jī)，振蕩電路的晶振采用12MHz，由控制核心 AT89C51 單片機(jī)、電源、振蕩電路、復(fù)位電路、交通燈電路組成。每條線的結(jié)構(gòu)組成如圖 。P2 口也是一個準(zhǔn)雙向口，它有兩 種使用功能：一種是當(dāng)系統(tǒng)不擴(kuò)展外部存儲器時，作普通 I/O 口使用，其功能和原理與 P0 口第一功能相同，只是作為輸出口時不需外接上拉電阻；另一種是當(dāng)系統(tǒng)外擴(kuò)存儲器時， P2 口作系統(tǒng)擴(kuò)展的地址總線口使用，輸出高 8 位的地址 A7～ A15，與 P0 口第二功能輸出的低 8 位地址相配合，共同訪問外部程序或數(shù)據(jù)存儲器 (64 KB)。在 FLASH 編程期間，此引腳用于輸入編程脈沖。 /PSEN：外部程序存儲器的選通信號。 振蕩器特性 : XTAL1 和 XTAL2 分別為反向放大器的輸入和輸出。黃燈閃爍 5 次（ 5秒）后，如圖 所 示，南北方向開始通車，通行時間為 25 秒。 軟件調(diào)試 軟件調(diào)試采用 Keil uVision4 軟件 ，將編好的程序進(jìn)行調(diào)試，主要是檢查語法錯誤。 在這次實習(xí)中，正確的思路是很重要的，只要設(shè)計思路是正確的，那么才有可能成功。 總體來說，這次課程設(shè)計讓我受益匪淺。 sbit lu2=P0^5。 hong1=1。 delay_50ms(15)。 delay_50ms(15)。 delay_50ms(15)。 delay_50ms(15)。 delay_50ms(15)。 delay_50ms(15)。再多華麗的言語也顯蒼白。從本課題的選題、方案設(shè)計以及后面的論文撰寫與修改，唐師嚴(yán)謹(jǐn)?shù)慕虒W(xué)態(tài)度、對我們的耐心指導(dǎo)都給與了我極大的幫助。t appealed against the disciplinary action your employer has taken against you. However, if you win your case, the tribunal may reduce any pensation awarded to you as a result of your failure to appeal. Remember that in most cases you must make an application to an employment tribunal within three months of the date when the event you are plaining about happened. If your application is received after this time limit, the tribunal will not usually accept i. If you are worried about how the time limits apply to you, take advice from one of the anisations listed under Further help. Employment tribunals are less formal than some other courts, but it is still a legal process and you will need to give evidence under an oath or affirmation. Most people find making a claim to an employment tribunal challenging. If you are thinking about making a claim to an employment tribunal, you should get help straight away from one of the anisations listed under 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 a damagesbased agreement. In England and Wales, your solicitor can39。s governing body, has also ordered an immediate investigation into the referee39。 Junior high school, thought to have a crush on just means that the real growth, but over the past three years later, his writing of alumni in peace, suddenly found that isn39。想要的，不想要的，界限明確，好像沒有什么可以撼動自己。t start planning... Those years, those days of do, finally, like youth, will end in our life. 此刻，天空是陰暗的，空氣里有 著剛下過雨之后的清新因子。 Baumgartner the disappointing news: Mission aborted. r plays an important role in this mission. Starting at the ground, conditions have to be very calm winds less than 2 mph, with no precipitation or humidity and limited cloud cover. The balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our daytoday weather lives. It will climb higher than the tip of Mount Everest ( miles/ kilometers), drifting even higher than the cruising altitude of mercial airliners ( miles/ kilometers) and into the stratosphere. As he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence. The supersonic descent could happen as early as Sunda. The weatheThe balloon will slowly drift to the edge of space at 120,000 feet (