简易数字电压表解析

~ 学年第学期

《单片机》

课程设计报告

题目：简易数字电压表

专业：自动化

班级：自动化（2）班

姓名：

指导教师：

电气工程系

2011年5月12日

摘要

随着时代的进步，用指针式万用表测量小幅度直流电压已经显得有些不太方便。因为指针式的测量不够精确，随着长时间的使用可能会造成欧姆调零以及机械调零的磨损，这都会对数据的测量造成很多困难，而采用数字式电压表来测量就可以避免这种情况的发生，而且操作更加方便。下面本文将介绍一种由数字电路以及单片机构成的数字电压表的设计方法。数字电压表（Digital V oltmeter）简称DVM，它是采用数字化测量技术，把连续的模拟量（直流输入电压）转换成不连续、离散的数字形式并加以显示的仪表本设计运用AT89C52单片机和ADC0809进行A/D转换,根据数据采集的工作原理，设计数字电压表，最后完成单片机与PC的数据通信,传送所测量的电压值。该新数字电压表测量电压类型是直流,测量范围是0-51V(本设计量程为0-5V)。电路包括:数据采集电路的单片机最小化设计、单片机与PC接口电路、单片机钟电路、复位电路等。下位机采用89C52芯片,A/D转换采用ADC0809芯片。通过RS232行口与PC进行通信,传送所测量的直流电压数据。

关键词：ATC89C52 ADC0809数模转换器数码管MAX232译码器

Abstract

With the progress of the times, with a multimeter measuring small amplitude DC voltage has been somewhat less convenient. Because of the pointer type measurement is not accurate enough, with the use of long time may cause ohms zero and mechanical zero wear, it will cause a lot of difficulties to measure data, and using the digital voltmeter to measure can prevent this from happening, and the operation is more convenient. This paper will introduce a kind of digital voltage meter is composed of a digital circuit and MCU design method. Digital voltmeter (Digital V oltmeter) referred to as DVM, it is the use of digital measuring technology, the continuous analog (DC input voltage) into discontinuous, discrete digital form and to display the design using AT89C52 single chip microcomputer and ADC0809 A/D conversion, according to the working principle of the data acquisition, the design of digital voltage meter, data communication finally completed the SCM and PC, transmit the measurement of voltage. The new digital voltmeter to measure the voltage type is DC, the measuring range is 0-51V (the design range is 0-5V). The circuit includes: data acquisition circuit of the MCU minimum design, interface circuit, SCM and PC MCU clock circuit, reset circuit etc.. The machine adopts 89C52 chip, A/D conversion chip ADC0809 is used. Communication through the RS232 port and PC data transmission, DC voltage measurement.

Keywords: ATC89C52 ADC0809 DAC digital tube MAX232 decoder

插图清单

图2-2 51型单片机引脚 (5)

图2-3 ADC0809引脚图 ................................................................................ 错误！未定义书签。图3-1 系统框图 ............................................................................................ 错误！未定义书签。图3-2 电源模块 ............................................................................................ 错误！未定义书签。图3-3 ADC模数转换 .................................................................................... 错误！未定义书签。图3-4 单片机最小系统 ................................................................................ 错误！未定义书签。图3-5 液晶显示电路 .................................................................................... 错误！未定义书签。图4-1 主程序流程图 .................................................................................... 错误！未定义书签。图4-2 子程序流程图 .................................................................................... 错误！未定义书签。图5-1 总电路图 ............................................................................................ 错误！未定义书签。图5-2 仿真结果 ............................................................................................ 错误！未定义书签。

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