电子设计精品 电子听诊器.doc

基于单片机的超声波测距系统的设计与实现
中文摘要
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,被广泛的用于距离的测量,如测距仪和物位测量仪等都可以通过超声波来实现。利用超声波检测往往比较迅速、快捷、方便简单、易于做到实时控制。是一种非接触式的检测方式,与其他方法相比不受光线,被测对象颜色的影响,对于被物体处于黑暗、有灰尘、烟雾、有毒等恶劣环境下有一定的适应的能力。
本文介绍了超声波测距系统的方法和原理。本次设计用CD4049、CX20106芯片实现对超声波的发射与接收,采用AT89C51型单片机作为主控制器,对发射、接收电路的数据进行控制和处理,用动态扫描的方式实现数码管的距离数字显示。在介绍测距系统功能的基础上,给出系统的整体构成,对系统中发射、接收、显示电路给出了软硬件的论证。经过调试本系统在5~200cm的距离内测量精度可达±1cm,实际使用表明该系统工作稳定, 性能良好。
关键词:超声波;测距;单片机;数码管
Design and Implement of Ultrasonic Distance
Measuring system based on single chip puter
ABSTRACT
Because the ultrasonic wave has the features ,such as strong point,slow energy consumption and a long distance transmission in the medium ,it always used for ultrasonic,energy consumed slowly,and transmiting more further in the medium, ultrasonic is often used for distance as range finders and all level measurement can be achieved through the ultrasonic wave .Use of ultrasonic testing is often more rapid,convenient and simple terms,easy to real-time is a non-contact detecttion pared with other methods,it is not influenced by light,color and other effects of the tested the measured objected in the dark, dusty, smoggy,toxic and adverse circumstances,ultrasonic wave has a certain degree of adaptability.
This text has mainly described the principle and method of ultrasonic range- design adopt the CD4049, CX20106 chip to achieve transmitting and receiving of ultrasound,using AT89C51 single-chip puter as the main controller to control and process of data of the transmitter and receiver circuitry,the dynamic scanning method to achieve digital distance on introducing the function of ultrasonic ranging system,this thesis raises the position of the system and gives the system transmitter and receiver, the display circuit hard ware and software of the system the distance measurement can measure in 5 ~ 200cm,the accuracy up to ± 1cm, and the actual use shows that the