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 AT89C52 设计一个数字万用表，能够测量直流电压值、直流电流、直流电阻，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，单片机系统设计采纳 AT89C52 单片机作为主控芯片，驱动液晶显示管显示。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 AT89C52 单片机 AD 转换与控制AbstractThis design is design a digital universal meter with chip AT89C52 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 AT89C52 one-chip computer as the top management chip, urge 4 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. Keyword: Digital universal meter AT89S52 one—chip computer AD changes and controls 一、设计背景数字万用表亦称数字多用表，简称 DMM(Digtial Multimeter）。它是采纳数字化测量技术，把连续的模拟量转换成不连续的、离散的数字形式并加以显示的仪表。传统的指针式万用表功能单精度低，不能满足数字化时代的需求，采纳单片的数字万用表，精度高、抗干扰能力强，可扩展尾强、集成方便，目前，由各种单片机芯片构成的数字电万用表，已被广泛用于电子及电工测量、工业自动化仪表、自动测...
