毕业设计 基于单片机的超声波液位测试系统研制.doc

摘 要 本系统以AT89S52单片机为核心，利用超声波测距原理，通过硬件电路和软件编程实现对液位高度的检测。其主要原理是由单片机控制超声波测距模块DYP-ME007发射超声波，遇到液面反射后模块接收回波，同时单片机记录所用时间。为了提高精度，计算时涉及到温度补偿。将测得的温度与时间带入相应公式，即可求得当前液位。最后通过LCD液晶不断更新显示当前温度与液位。若液位超出预设的最低值或最高值，液晶显示警告，同时蜂鸣器报警。 硬件部分包括AT89S52单片机，DYP-ME007超声波测距模块，12864LCD液晶显示模块，DS18B20温度测量模块和蜂鸣器报警模块。软件设计分为两部分，主程序和中断服务程序。主程序完成初始化、超声波发射和接收，温度测量，距离计算、结果显示等大部分主要工作。中断服务子程序主要完成时间值的读取。 关键词：单片机；超声波测距；液位测量；温度补偿?? Abstract The system use the AT89S52 microcontroller as the core, using ultrasonic ranging principle, through a combination of hardware and software, and debugging, and ultimately to the liquid level detection. The main principle is controlled by the microcontroller module DYP-ME007 ultrasonic distance ultrasonic transmitter, and receives the echo reflected surface encountered while recording the time used microcontroller. For improved accuracy, temperature compensation calculations involved. The measured temperature and time into the appropriate formula to obtain the current level. Last updated through the LCD liquid crystal display the current temperature and level. If the level exceeds the preset minimum or maximum value, liquid crystal display a warning buzzer alarm. AT89S52 microcontroller hardware including, DYP-ME007 ultrasonic distance measuring module, 12864LCD LCD module, DS18B20 temperature measurement module and the buzzer alarm module. Software design is divided into two parts, the main program and interrupt service routine. Main program to initialize, transmit and receive ultrasound, temperature measurement, distance calculation, the results display most of the major work. Interrupt service routine reads the key values ??of completion time. Key words: SCM; Ultrasonic distance measurement; liquid level measurement; temperature compensation 目 录 第1章 概 述 1 1.1 课题的背景和意义 1 1.2 液位测量系统的现状 2 1.3 液位传感器的发展方向 3 1.4 国内外液位监测技术的发展现状 3 1.5 本章小结 4 第2章 超声波测液位系统 5 2.1 超声波与超声波传感器 5 2.2 超声波测液位原理 5 2.3 超声波测距原理 6 2.4 总体方案设计 7 2.5 本章小结 8 第3章 硬件系统设计 9 3.1 单片机系统 9 3.2 发射电路方案比较 12 3.3 接收电路方案比