基于单片机at89c51的数字万用表设计.doc

基于单片机的数字万用表设计This design is design a digital universal meter with chip AT89s51 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 AT89S51 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. 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 AT89S51 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. Keyword: Digital universal meter AT89S51 one-chip computer AD changes and controls  目 录 摘 要 i Abstract ii 1. 绪论 4 1.1 数字万用表的主要特点 4 1.2 数字万用表设计背景 6 1.2.1 数字万用表的设计目的和意义 6 1.2.2 数字万用表的设计依据 6 1.2.3 数字万用表的设计目的和意义 6 1.3万用表发展趋势 7 2. 数字万用表总体设计方案 8 2.1数字万用表的基本原理 8 2.2数字万用表的硬件系统设计总体框架图 15 3. 选用芯片介绍及硬件电路设计方案 16 3.1 芯片选择及功能简介 16 3.1.1 AT89c51 芯片功能特性描述 16 3.1.2 ADC0809 介绍 19 3.1.2 TEC6122 简述 21 3.2设计方案及数字万用表的硬件设计 24 3.2.1 设计方案 24 3.2.2 数字万用表的硬件设计 26 3.2.2.1 分模块详述系统各部分的实现方法 26 3.2.2.2 数字万用表控制硬件整体结构图 32 3.2.2.1电路的工作过程描述 32 4. 系统软件与流程图 33 4.1 电路功能模块 33 4.2系