毕设论文—数字电容测量仪设计.doc

摘要 当前现代化电子市场正朝着快速及便利同时大容量的方向发展，现代电子产品几乎能运用到社会的各个领域当中，有力的推动了社会现代化的发展。同时，电子产品也被要求以更快速度的升级和更快速的处理。 本设计以STC89C52单片机和555振荡器作为主要元件，来实现对电容容量的基本测量。本设计基于555振荡器构成多谐振荡器来产生输入脉冲信号，然后再通过STC89C52单片机对方波脉冲进行中断计数而测量电容的。在多谐振荡器输出端加入一个74HC08使输出波型毛刺减少，从而使单片机测量结果变精确。555振荡器所产生的信号会根据所选的电阻的阻值不同，从而调节电容的参数值，这样就可以确定被测电容的容值范围，最后通过LCD1602显示器显示被测电容容值。在软件设计中，该设计使用C语言来编写程序。该仪器具有方便快捷，简单实用，价格低廉等特点。 关键词：电容测量;555振荡器;STC89C52;LCD1602 Abstract The current modern electronic market is headed in fast and convenient large capacity and the direction of development, modern electronic products to use to almost all areas of society of powerful promoted the development of modern society. At the same time, the electronic products also are required to faster speed upgrade and more fast process. This design to STC89C52 single-chip microcomputer and 555 oscillator as the main components, to realize the basic capacity of capacitance measurement. This design based on the 555 oscillator to generate more than a harmonic oscillator input pulse signal, and then through the STC89C52 microcontroller each other to interrupt pulse count and measurement of capacitance. In order to join the output oscillator a 74 HC08 to make the output waveform burr reduced, so that the single chip microcomputer variable precision measurement results. 555 oscillator generated signal will be selected according to the resistance of the resistance is different, which regulates capacitance parameter value, which can determine the capacity of the capacitance value range, the last through the LCD1602 display shows measured capacitance let value. In software design, this design using C language to write the program. The instrument has convenient and quick, simple, practical, and low prices, etc. Keywords: capacitance measurements;555 oscillator;STC89C52;LCD1602  目录 摘要 I Abstract II 目录 I 1 绪论 1 1.1 引言 1 2 STC89C52单片机的基本功能及应用 2 2.1 STC89C52芯片介绍 2 2.2 STC89C52应用说明 3 2.3 单片机工作的最小化配置 4 3 系统设计 5 3.1 设计要求 5 3.2 整体方案设计 5 4 硬件设计