基于单片机的超声波测距仪设计与制作.doc

毕 业 设 计 [论 文] 题 目： 基于单片机的超声波测距仪设计与制作 学 院： 电气与信息工程学院 专 业： 电子信息工程 姓 名： 学 号： 指导老师： 郭蓓蕾 完成时间： 2013年5月31日 摘 要 随着社会的发展，人们对距离或长度测量的要求越来越高。在社会生活超声波测距技术已，如汽车倒车雷达、测距仪和物位测量仪等都可以通过超声波来实现。由于超声波指向性强，能量消耗缓慢，在介质中传播的距离较远，因而超声测距技术的研究和开发具有实际意义。 本文介绍了一种利用超声波测距的系统，该系统是一种基于单片机的超声波测距系统，它根据超声波在空气中传播的反射原理，以超声波传感器为部件，应用单片机技术和超声波在空气中的时间差来测量距离。该系统主要由主控制器模块、超声波发射模块、超声波接收模块和显示模块等四个模块构成。通过单片机的I/O口控制超声波发射电路发出40KHz的超声波，反射波经由超声波检测接收电路、放大电路送入单片机端，通过计算超声波的发射和返回的时间，确定超声波发生器和反射物体之间的距离，完成测距。超声波测距仪Abstract With the development of society, the demand on the measurement of distance or length is increasing. It is applied widely by ultrasonic to measure distance, such as cars reversing radar， range finder and level measurement and so on. Because of the strong point of ultrasonicenergy consumption, long distance transporting in media, thus it is practical and significant to measure distance by ultrasonic. In this paper, it introduces a system to measure distance by ultrasonic, which is based on the AT89C52.The theory is based on the principles of reflection of ultrasonic spreading in the air. The system uses ultrasonic sensors as a detector, and applies MCU and the time difference of ultrasonic spreading in the air to measure the distance. The system consists of the main controller module, ultrasonic transmitter module, ultrasonic receiver module and display module. The MCU I / O port controls ultrasonic transmitter to send 40 KHz ultrasonic, and the reflecting signal is received by the ultrasonic receiver circuit, and it is amplified, and finally, it starts the interrupter of the MCU.The MCU calculates the time of launch and return of ultrasonic to get the distance between the ultrasonic generator and the reflective objects. The entire hardware circuit is composed by ultrason