摘要超声波测距技术具有良好的非接触性，因此超声波在对距离，速度的测量， 对于物体的焊接，物体损伤的检测，医学成像等方面均具有广泛的应用。本设计 通过结合单片机强大的控制、处理功能以及超声检测的优越性，开发设计出可用 于测量距离的超声波测距系统。对于测量出的测距值设定一定的报警阈值，一旦 低于设置的报警值，就由单片机发出指令，控制蜂鸣器报警[1]，当测得的距离越 来越小，蜂鸣器报警的频率越来越高。经实验，这次设计的超声波测距系统的测 量范围 2cm-4m，灵敏度高，达到了预期的设计目标。73963

该论文有图 15 个，参考文献 7 篇。

毕业论文关键词：超声波 测距 报警 STC89C52

Ultrasonic Ranging System Based on Single Chip Microcomputer

Abstract The technology of measuring distance by the ultrasonic signal is characteristic of non-contact,so it is widely used in many fields,such as the measuring of diatance and cleaning and speed and the wielding and cleaning of objects。This design mainly studies how to measure the distance by the use of STC89C52 single chip microcomputer and ultrasonic wave sensor 。 STC89C52 single chip microcomputer。 as the main control chip disposes and operates the distance measured by the ultrasonic wave sensor,Then the disposed result is compared with the set mainly value。Once the result drops below the value, STC89C52 single chip microcomputer wouid give commands and instructions,controlling the buzzer to warn。With the distance shortening, the frequency of warning becomes higher。 In the experiment,the designed system measuring the distance by ultrasonic signal has a feature of hign sensitivity and can measure the length from two centimeters to four meters, which reaches the design goal。

This paper has 15 figures and 7 references。

Key Words：ultrasonic ranging alarm STC89C52

目 录

摘 要 I

Abstract II

目 录 III

1 绪论 1

2 总体设计方案及论证 2

3 硬件实现及单元电路设计 3

3。1 主控制模块 3

3。2 电源设计 4

3。3 超声波测试模块 4

3。4 超声波传感器原理 7

3。5 测距分析 8

3。6 时钟电路的设计 10

3。7 复位电路的设计 10

3。8 声音报警电路的设计 10

3。9 显示模块 11

4 软件设计 13

5 总结 15

参考文献 16

致 谢