摘要：数字频率计是一种基本的测量仪器。它被广泛应用于航天、电子、测控等领域，还被应用在计算机及各种数学仪表中。一般采用的是十进制数字，显示被测信号频率。基本功能是测量正弦信号，方波信号以及其他各种单位时间内变坏的物理量。由于其使用十进制数显示，测量迅速精确，显示直观，所以经常被用来使用。91264

本课题设计了一个基于52单片机控制的数字频率计，以单片机STC89C52单片机为核心，设计一种数字频率计，它由放大整形电路、分频电路、单片机、显示电路等组成，应用单片机中的定时/计数器和中断系统等完成频率的测量，实现1Hz~20MHz的频率测量，该设计与传统测频系统相比，具有体积小、成本低、低功耗、精度高等优点，适用于各种测量电路。

毕业论文关键词：频率计，分频，测量

Abstract: Basic surveying instrument digital frequency meter。 It is widely, spaceflight, electron, it has been applied to the fields such as remodeling in various computers and mathematics。 The general decimal numbers, the signal frequency is presented。 The basic function of the sign signal measuring physical quantities in unit time, the worse the square wave signal and a variety of other。 It uses a decimal number display, accurate measurement, fast, intuitive, so the use is often used。

Digital frequency meter 52 weeks based on macro processor control was designed in this subject, the center of the C macro processor 52 weeks STC macro processor, digital frequency meter is a kind of the design, it is amplified shaping circuit, a frequency piding circuit, a week from the macro processor and display circuit, the complete the week number and time counter of the application processor system in macro interrupted wave measurement, measurement of Hz week 1 to 20 MHz, design and traditional measurement system, the number of weeks compared with small size, low cost, low power consumption, high accuracy of measurement circuit。

Key words: Frequency counter,frequency pision,measure

目 录

1 前言 4

2 系统总体方案设计 4

2。1 设计要求 4

2。2 测频法 5

2。3 系统设计方案 5

3 系统硬件设计 6

3。1 主控模块 6

3。1。1 STC89C52单片机 7

3。1。2 单片机最小系统 11

3。2 LCD液晶显示器模块 11

3。2。1 液晶原理介绍 11

3。2。2 液晶模块简介 12

3。3 三极管放大电路 13

3。4 整形模块 14

3。4。1 施密特触发器芯片介绍 14

3。4。2 74HC14电路设计 15