摘要：现如今随着科技不断地发展，人们对汽车的需求越来越大，就会出现很多交通问题。在这样的形势下，辅助汽车安全的系统也出现的很多。这个设计是把AT89C51单片机和超声波传感器相结合研发出来测量距离的系统。在倒车和行驶途中，在驾驶员没办法用眼睛测量与障碍物距离时，该测距仪会发出提示警报。利用用超声波传输中距离与时间的关系，采用51单片机进行控制及数据处理，设计出了能精确测量两点间距离的系统。最后利用Proteus仿真将两者相结合，让每个模块的功能都能够实现。该系统的优点是：容易控制、测距精准、实时监测、工作可靠、过程简易。设计完成后的超声波测距仪可以在各种情况下实现测距功能。73160

毕业论文关键词：AT89C51，超声波，测距，蜂鸣器

Abstract: Now with the continuous development of science and technology, people's demand for cars is getting bigger and bigger, there will be a lot of traffic problems。 In such a situation, the auxiliary car safety system also appears a lot of。 This design is the AT89C51 microcontroller and ultrasonic sensors combined with the research and development of measuring distance of the system。 In reverse and travel on the way, in the driver can not be measured with the eye when the distance between the obstacle, the range finder will issue a warning alert。 Using the relationship between the distance and time in the ultrasonic transmission, the control and data processing of 51 single chip microcomputer is used to design a system which can accurately measure the distance between two points。 Finally, using Proteus simulation to combine the two, so that the function of each module can be achieved。 The advantages of the system are: easy to control, ranging precision, real-time monitoring, reliable work, simple process。 After design the ultrasonic distance measuring instrument can realize the function of distance measurement in all kinds of situations。 

Key words: AT89C51, ultrasonic wave, measure distance, buzzer alarm

目录

1 绪论 4

1。1 课题研究背景 4

1。2 课题研究意义 4

1。3需要解决的重要问题 4

2 总体设计方案论证 5

2。1 方案设计 5

2。2 超声波测距理论 5

2。3 方案论证 6

2。4 关键元件介绍 7

3硬件实现和电路设计 8

3。1主控模块

3。2 超声波发射电路 8

3。3 超声波接收电路 9

3。4显示电路 10

3。5 电源设计 11

3。6 复位电路 12

3。7 蜂鸣器报警电路 12

3。8 时钟电路 13

4 软件设计 13

4。1 主程序流程图 13

4。2 中断服务程序的流程图及编制 15

4。3  显示距离子程序和延时子程序 16

5 软件调试及系统仿真 17