摘要:本论文是基于单片机的应用设计。以声波在空气中传播速度可以测算和接收为基础。超声波数字测距系统是通过STC89C52单片机与DS1820温度传感器，SMC1602显示器组合连接。通过温度补偿电路、超声波测距的计算，较准确的测算出距离的传感器。本系统具有低成本，携带方便，测距方法快捷，方便，可以实时控制，能够在工业和日常生活中运用等优点。本文阐述了基础理论和仪器的软硬件原理等内容，以及超声波测距的现状和前景。

　　　本课题考虑到成本和功能采用了STC89C52做设计，单片机采用宏晶公司STC89C52芯片，该芯片为增强型51单片机，管脚与程序与传统51单片机完全兼容，但主频更高、容量更大、性能更强。DS1820数字温度计测量温度。采用了最小所需的硬件和高精度US-100超声波收发模块，测量精度高，测量距离远。在keil C51软件上设计好代码后烧录至硬件上调试、测试。最终控制在温度为-20℃—70℃，测量的范围为5cm—400cm。经实际测试计算后误差控制在5%范围以内。

关键词： 超声波; 单片机; 测距

Abstract:This paper is based on single chip microcomputer application design. Based on the propagation velocity of sound in air can be measured and receive. Digital ultrasonic ranging system by STC89C52 microcontroller and DS1820 temperature sensor, the SMC1602 display portfolio connection. The calculation of the temperature compensation circuit, ultrasonic ranging, more accurately measure the distance sensor. This system has a low-cost, easy to carry, the ranging method is fast, convenient, real-time control, you can use in industry and daily life, etc.. This paper describes the basic theory and principles of the instrument hardware and software, and the status and prospects of ultrasonic distance measurement.

　　　This subject taking into account the cost and functionality using STC89C52 do the design, microcontroller Hongjing STC89C52 chip, the chip is fully compatible with the enhanced 51 MCU pins, and procedures with the traditional 51 single-chip, but a higher frequency, greater capacity,and more powerful. The DS1820 digital thermometer to measure temperature. Minimum required hardware and precision US-100 ultrasonic transceivers, high accuracy, measuring the distance. Design code in keil C51 software, burn them to a hardware debugging and testing. Ultimately control the temperature of -20 ℃ -70 ℃, the measurement range is 5cm-400cm. After the calculation of the actual test error control in the range of 5% or less.

Key words： Ultrasonic wave；single-chip microcomputer； Ranging

　　　超声波在传播的过程中有指向性强，能量消耗小，所以在介质中传播的距离较远。因此常常被人们用作距离测量。利用单片机控制超声波传感器，可以有效的降低成本，并且有方便、快捷、计算简单、易于实时控制等优点，而且测量的精度较高。

　　　超声波数字测距传感器可以应用在汽车倒车雷达、测距仪、移动机器人的开发、建筑工地的施工现场等，例如：管道的长度、流速、井深、液位、距离等场合。所以有着广泛应用，本课题的研究非常具有实用和商业价值。