基于单片机的数字电压表系统.doc

摘 要 如今，数字电压表已绝大部分取代了传统模式的模拟指针电压表。因为传统的模拟指针式电压表功能单一，精度低，读数的时候也非常不方便，也很容易出错。而采用单片机的数字电压表由于测量度高，速度快，读数时也非常的方便。抗干扰能力强，可扩展性强等优点已被广泛应用于电子及电子工程，显示出强大的生命力。 本电压表设计以单片机为中心，采用A/D转换芯片结合的方法，分为三个档位2V，20V，200V可以通过调档开关来实现三个档位。本设计中选用是51系列的AT89C52，它是低电压、低功耗、高性能的CMOS8位单片机，片内含8KB的可反复擦写的只读程序存储器和256B的随机存取数据存储器，32个I/O口线，3个16位定时/计数器，片内振荡器及时钟电路，并与MCS-51系列单片机兼容。在设计中，单片机起着连接硬件电路与程序运行及存储数据的任务，一方面，它将A/D转换器、显示器和语音芯片等通过I/O口地址线和数据线连接起来；另一方面，它将用户下载的程序通过控制总线控制数据的输入输出，从而实现册电压的功能。 现在，数字电压表的发展已经是非常的成熟，就原理来讲，它从原来的一，二种已发展到多种，在功能上讲，则从测单一参数发展到能测多种参数；从制作元件来看，发展到了集成电路，准确度已经有了很大的提高，精度高达1NV；读数每秒几万次，而相对以前，它的价格也有了降低了很多。 关键词：A/D转换芯片；AT89S52；1602显示器 Abstract Now, the digital voltmeter major part has substituted for the traditional pattern simulation indicator voltmeter. Because the traditional simulation indicator type voltmeter function is unitary, the precision is low, reading time is not also convenient, also very easy to make a mistake. But uses monolithic integrated circuits digital voltmeter, because measures measures high, the speed is quick, when reading also unusual convenient. Antijamming ability, the extendibility strong and so on merits have been widely applied in electronic and the electronic engineering, demonstrated formidable vitality the this voltmeter design take the monolithic integrated circuit as a center, uses a/D transformation chip union the method, divides into three files position 2V,20V,200V to be possible to realize three files positions through the shifting gear switch. In this design selects is 51 series AT89C52, it is the low voltage, the low power loss, the high performance CMOS8 position monolithic integrated circuit, internal may scratch the read-only program memory which and the 256B random access data-carrier storage repeatedly including 8KB writes, 32 I/O mouth line, 3 16 fixed time/counters, the internal oscillator and the clock circuit, and is compatible with the MCS-51 series monolithic integrated circuit. In the design, the monolithic integrated circuit gets up is connecti