基于单片机数字式频率计的硬件设计

论文编号:DQ201论文字数:20314,页数:49

摘要

数字式频率计在现代化工业技术上得到广泛的应用，其作用为对周期信号实现频率与周期参数的测量。本文以单片机为核心，引入相应的外围硬件电路，设计制作了一个数字式频率计系统。系统的硬件电路由单片微处理器、信号整形与放大电路、隔直电路、触发电路、数据显示等部分组成。系统设计的基本思想是通过钳压电路对输入信号进行整形，由运算放大器电路对输入信号进行放大，经触发电路实现输入信号的锁存，单片微处理器完成信号的处理与运算，利用译码器译码，在LED显示器上显视被测频率参数。实际运行表明，所设计的系统运行正常，结果正确。同时，通过对输入信号的波形整形可实现对各种周期性变化信号的频率及周期参数测量，若配以适当的传感器，本系统也可实现多种非电量周期信号参数的测量，如机械振动的频率，转速，声音的频率等。

关键词： 数字频率计，单片机系统，硬件设计

Abstract

Intelligent digital frequency meter is widely applied in the modern industrial technology, whose role is to realize the signal measurement of the cycle frequency. Based on the single-chip microcomputer, and introduced by relative the periphery circuits, a digital frequency meter system was designed and established. The hardware circuit consisted of the single-chip microprocessors, signal shaping and amplification circuits, DC circuits, trigger circuit, display circuit, and other components. System design through the basic idea is to clamp voltage circuit of the input signal shaping，op amp circuit from the input signal amplification, by the trigger circuit latches the input signal to achieve, complete single-chip microprocessor signal processing and computing, the use of decoder decoding, in the LED display on the frequency of significant parameters, as measured.Show that the actual operation, system designed to run normal, andthe results of the correct. At the same time, by shaping the waveform of the input signal can be achieved on a variety of cyclical changes in the frequency and signal parameter measurement cycle, the sensor with the appropriate, the system also enables a variety of non-periodic signal power measurement parameters, such as the frequency of mechanical vibration, speed, the frequency of sound.

Key words：Digital frequency meter，single-chip microcomputer system,，hardware design

目录

摘要I

1 前言1

1.1 数字频率计研究的意义与目的1

1.2 数字频率计的现状和发展前景1

1.3 本文所做的主要工作2

2 89S51单片机简介3

2.1 89S51 和MCS-51 的区别3

2.2 89S51单片机的基本组成5

2.3 89S51单片机工作方式7

2.4 89S51单片机并行I/O接口8

2.5 89S51单片机串行接口9

2.6 89S51单片机中断系统11

3 外围电路设计13

3.1 信号输入单元13

3.1.1信号输入单元原理图13

3.1.2信号输入单元电路图14

3.1.3 741型集成运放电路简介14

3.2 数字显示电路17

3.2.1 元件引脚图17

3.1.2 元件功能表18

3.2.3 数码显示管介绍18

4 数字式频率计硬件设计22

4.1 数字频率计的工作原理22

4.2 数字频率计的系统级框图22

4.3 数字频率计硬件设计原理22

4.4 系统总设计23

2.5 系统硬件调试25

2.6 硬件调试工具—面包板简绍25

2.7 系统元器件简绍25

2.7.1 电阻25

2.7.2 电容27

2.8 PROTEL介绍29

5 软件系统设计31

5.1程序的设计总述31

5.2数字频率计系统总体程序31

5.3程序调试42

6 总结43

致谢44

参考文献45

附录：数字式频率计原理图 46