文档介绍：基于单片机的频率测量仪的设计
摘要
当今社会,电子技术迎来了飞速的发展,而频率作为电子电工学中一个极重要的参数,测量频率的重要性不言而喻。同时频率测量仪也是计算机,通讯设备,音频视频等科研领域不可或缺的测量仪器。为了得到性能更好的电子系统,一个精准的频率测量仪必不可少。
该文主要论述了基于STC89C52单片机设计的数字频率计,具有测量范围宽,响应频率范围广,测量速度快,体积小,精度高的优点。它主要由低通滤波电路,过零比较电路,分频电路,MCU控制电路,测量结果显示电路组成。可以自动检测频率切换测量档位,高频的时候采用分频计数法测量频率提高精度,低频的时候采用测宽法进行频率测量以尽可能的缩短测量时间。它可以测量的信号有方波,三角波,正弦波,锯齿波等各种各样的信号,~5MHz。
关键词:计数法测宽法分频 ~15MHz
ABSTRACT
Nowadays, electronic technology ushered in rapid development, and the frequency of an electronic electrical engineering as a very important parameter, so measuring frequency e so important. Meanwhile frequency meter puters, communications equipment, audio and video and other research areas indispensable measuring instruments. To get better performance of electronic systems, a precision frequency meter is essential.
This paper mainly discusses STC89C52 microcontroller based design digital frequency meter, wide measuring range, frequency response range, measurement speed, small size, high accuracy. It mainly consists of a low-pass filter circuit, zero-parator circuit, frequency divider circuit, MCU processing circuit, the measurement results display circuit. Can automatically detect measurement frequency switching gear, high-frequency divider when the counting method used to improve the accuracy, wide measurement frequency when using the method of frequency measurement to measurement time as short as possible. It can measure the signal square wave, triangle wave, sine wave, sawtooth and other kinds of signals, the measurement frequency range of ~15MHz.
Keywords: Counting method Width measurement method frequency dividing ~15MHz
目录
第一章绪论 1
课题背景 1
频率计目前发展概况 1
课题研究目的及意义 2
数字频率计设计任务与要求 3
第二章总体设计 5
方案论证 5
方案比较 6
方案选择 7
第三章硬件设计原理 9
数字频率计硬件系统框架 9
主控电路的设计 9
STC89C52RC芯片介绍 9
芯片主要参数 10
芯片主要引脚功能 10
单片机定时器介绍 11
单片机部分电路设计 12
信号处理电路设计 13
高频滤波 13
过零比较电路 13
分频电路设计 14
74LS