基于单片机的数字万用表设计

摘 要

 本次设计用单片机芯片AT89s52设计一个数字万用表，能够测量交、直流电压值、直流电流、直流电阻以及电容，四位数码显示。此系统由分流电阻、分压电阻、基准电阻、电容测试芯片电路、51单片机最小系统、显示部分、报警部分、AD转换和控制部分组成。为使系统更加稳定，使系统整体精度得以保障，本电路使用了AD0809数据转换芯片，单片机系统设计采用AT89S52单片机作为主控芯片，配以RC上电复位电路和11.0592MHZ震荡电路，显示芯片用TEC6122，驱动8位数码管显示。程序每执行周期耗时缩到最短，这样保证了系统的实时性。

关键词     数字万用表  AT89S52单片机  AD转换与控制
Abstract
 This design is design a digital universal meter with chip AT89s52 of one-chip computer, can measure and hand in , direct current pressing value , direct current flow , the direct current is hindered, four numbers show. This system is shunted resistance, resistance of partial pressure, basic resistance, minimum system of 51 one-chip computers, shown that some , warning part , AD change and control making up partly. In order to make the system more steady, make the whole precision of the system be ensured, this circuit has used AD0809 data to change the chip, the one-chip computer system is designed to adopt AT89S52 one-chip computer as the top management chip, the electricity is restored to the throne the circuit and 11.0592MHZ and shaken the circuit to match on RC, show that the chip uses TEC6122, urge 8 numbers to be in charge of showing. The every execution cycle consuming time of procedure contracts to get shortest, in this way the real-time character of the security system.

[资料来源：http://THINK58.com]

Keyword: Digital universal meter  AT89S52 one-chip computer  AD changes and controls   
 

[资料来源：http://think58.com]

目    录 [资料来源：www.THINK58.com]

摘  要 i
Abstract ii
绪  论 5
1. 数字万用表设计背景 7
1.1数字万用表的设计目的和意义 7
1.2 数字万用表的设计依据 7
1.3数字万用表设计重点解决的问题 7
2 数字万用表总体设计方案 7
2.1数字万用表的基本原理 7
2.2 数字万用表的硬件系统设计总体框架图 13
2.3硬件电路设计方案及选用芯片介绍 14
2.3.1 设计方案 14
2.3.2 芯片选择及功能简介 14
2.4数字万用表的硬件设计 25
2.4.1分模块详述系统各部分的实现方法 25
2.4.2  数字万用表控制硬件整体结构图 30
2.4.3 电路的工作过程描述 30
3. 系统软件与流程图 32
3.1 电路功能模块 32
3.2系统总流程图 32
3.3物理量采集处理流程 34
3.4电压测量过程流程图 34
3.5电流的测量过程流程图 36
3.6电阻的测量过程流程图 37
3.7电容测量过程流程图 39
结  论 40
致  谢 41

[来源：http://think58.com]

[来源：http://www.think58.com]