基于單片機的交通燈系統(tǒng)設(shè)計
目錄
摘要……………………………………………………………1
引 言2
1 單片機概述 2
2 芯片簡介 3
2.1 MSC-51芯片簡介 3
2.2 8255芯片簡介 4
2.2.1 74LS373簡介 4
3 系統(tǒng)硬件設(shè)計 5
3.1 交通管理的方案論證 5
3.2 系統(tǒng)硬件設(shè)計 5
3.2.1 系統(tǒng)總框圖如下 6
3.2.2 交通燈硬件線路圖............................. . . . ........ 6
3.2.3 系統(tǒng)工作原理 7
4 控制器的軟件設(shè)計 7
4.1 每秒鐘的設(shè)定 7
4.2 計數(shù)器硬件延時 8
4.2.1 計數(shù)器初值計算 9
4.2.2 計算公式 10
4.2.3 １秒的方法 11
4.2.4 相應(yīng)程序代碼 12
4.3 軟件延時 13
4.4 時間及信號燈的顯示 14
4.4.1 8051并行口的擴展 15
4.4.2 顯示原理 16
4.4.3 8255PA口輸出信號接信號燈 16
4.4.4 8255輸出信號與數(shù)碼管的連接 16
4.4.5 8255與8051的連接 17
4.5程序設(shè)計 18
4.5.1 流程圖如圖所示 18
4.5.2 程序源代碼 18
結(jié)論 22
參考文獻........ . .................................. . ...........23

摘要:
近年來隨著科技的飛速發(fā)展，單片機的應(yīng)用正在不斷深入，同時帶動傳統(tǒng)控制檢測技術(shù)日益更新。在實時檢測和自動控制的單片機應(yīng)用系統(tǒng)中，單片機往往作為一個核心部件來使用，僅單片機方面知識是不夠的，還應(yīng)根據(jù)具體硬件結(jié)構(gòu)軟硬件結(jié)合，加以完善。
十字路口車輛穿梭，行人熙攘，車行車道，人行人道，有條不紊。那么靠什么來實現(xiàn)這井然秩序呢？靠的就是交通信號燈的自動指揮系統(tǒng)。交通信號燈控制方式很多。本系統(tǒng)采用MSC-51系列單片機ATSC51和可編程并行I/O接口芯片8255A為中心器件來設(shè)計交通燈控制器，實現(xiàn)了能根據(jù)實際車流量通過8051芯片的P1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（交通燈信號通過PA口輸出，顯示時間直接通過8255的PC口輸出至雙位數(shù)碼管）；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。本系統(tǒng)實用性強、操作簡單、擴展功能強。

關(guān)鍵詞：單片機， 交通燈， 闖紅燈，檢測車流量
abstract
In recent years, with the rapid development of science and technology, the application of SCM is unceasingly thorough, while traditional control testing technology is updated. In real-time detection and automatic control of single-chip microcomputer application system, often used as a core component, knowledge is not only the MCU, still should according to specific hardware structure, software and hardware, the perfect combination.
Pedestrian crossing transports, bustling, garage, pedestrian humanitarian, orderly driveway. So what to realize it in order? The traffic light automatic command system. Traffic light control many ways. This system USES MSC - 51 series microcontroller ATSC51 and programmable parallel the I/O devices for the center 8255A interface chip to design the controller, lights, can according to actual traffic through the 8051 chips red, green, P1 mouth setting time function; the depth Traffic light, circulation for 5 seconds remaining countdown yellow lights flashing warning (when the traffic signal output by mouth that time, PA directly through the mouth 8255 PC output to double a digital tube), Traffic police; red Green time can be detected by double bits of cars and digital tube display. This system is practical, simple operation and function expansion.

Keywords: red lights, SCM, traffic, detection