摘要万用表又叫做繁用表、三用表、多用表、复用表等，被作为电力电子等部门必不可少的测量仪器，普通仪表的功能以测量电阻、电流和电压这些参数为主。当今社会电子工业快速发展，设计制作使用更加方便、测量参数更多的电参数测试仪将具有十分宽广的应用前景。33346
在系统的硬件设计方面，电参数测试仪以AT89C52单片机为核心，通过一些简洁的硬件电路将电压电流电阻等电参数转化为电压模拟信号，由ADC0808转换芯片转为数字量，再送入52单片机处理，测量的精度较高。本测试仪能够准确地测试出电阻、直流电压、直流电流、频率、功率的数值，并且在 1602 液晶屏上显示出来。
在系统的软件设计方面，我们以 Keil为仿真平台，使用简单易懂的C语言来编写系统所用的软件。系统主要包括电阻测量、电压测量、电流测量、频率电路、功率电路、AD转换、LCD显示几个模块。
最后通过在 proteus 软件中仿真，经过各方面调试，结果表明本系统的功能和指标达到了设计要求。
关键词 52单片机   电参数测量   ADC0808  1602液晶屏  C语言
毕业设计说明书（毕业论文）外文摘要
Title   Digital electric parameter test instrument  
Abstract
The multimeter is also called multimeter,three meter, multimeter, multiplexing table,used as measuring instruments essential power electronics department, general instrument function to measure resistance, current and voltage of these parameters mainly.Today the rapid development of the electronic industry in society, design is more convenient to use, measurement parameters more electric parameter test instrument the application prospect is very broad.
In the hardware design of the system, electric parameter test instrument core is on AT89C52 microcontroller, through some simple hardware circuit voltage current resistance of electric parameters such as voltage conversion for analog signal by the ADC0808 conversion chip, converted to digital quantity, and then into the 52 single-chip processing, to high precision measurement. The tester can accurately test the numerical resistance, DC voltage, DC current, frequency, power, and displayed on the LCD screen in 1602.
In the system software design, we use Keil as the simulation platform, the use of simple C language to write the system software. The system mainly includes the resistance measurement, voltage measurement, current measurement, frequency circuit, power circuit, AD conversion, LCD display modules.
Finally, through the simulation in Proteus Software, debugging it, then the results show that the system functions and indicators have reached the design requirements.
Keywords: 52 Microcontroller   Measurement of electric parameters  ADC0808   LCD1602   C languge
目   次
1 绪论1
1.1 设计背景及意义1
1.2 电参数测试仪发展现状2
1.3 设计的任务及要求2
1.3.1 本设计课题应达到的目的3
1.3.2 本设计课题任务内容及要求3
1.3.3 本设计采用方案及成果要求3
2 系统设计方案3
2.1测量各参数选择方案与论证3
2.2设计思路4
2.3设计控制硬件6
2.3.1低功耗单片机AT89C526
2.3.2 A\D转换器ADC08088
2.3.3 LCD1602显示器8
3 数字式电参数测试仪硬件设计9
3.1 电阻测量电路9
3.2 电压测量电路10
3.3 电流测量电路11
3.4 频率测量电路12
3.5  功率测量电路13
3.6 A/D转换电路13
3.7 MCU原理图14
4 数字式电参数测试仪软件设计   15
4.1 软件控制测量流程图15
4．2测电压部分17
4.3测频率部分18
4.4测电阻部分19
4.5测电流部分19
4.6测功率部分21 AT89C52单片机数字式电参数测试仪设计+电路图+源程序:http://www.youerw.com/tongxin/lunwen_30473.html