简易的数字频率计

文档编号:DZXX094  文档字数:11400,页数:35

摘要
 数字频率计是一种基本的测量仪器。它被广泛应用与航天、电子、测控等领域。它的基本测量原理是，首先让被测信号与标准信号一起通过一个闸门，然后用计数器计数信号脉冲的个数，把标准时间内的计数的结果，用锁存器锁存起来，最后用显示译码器，把锁存的结果用LED数码管显示出来。本文主要讲述了数字频率计的工作原理以及其各个组成部分，以单片机AT89C52为核心，充分利用AT89C52中三个可编程定时/计数器，现实频率\周期的高精度测量。
 关键字：单片机、频率计
   
 AbstractThe digital cymometer is a kind of basic measuring instrument. It is widely used in such fields as the spaceflight , electron , observing and controlling ,etc. Basic measurement of it principle, is it examine signal adopt the gate together with standard signal to let at first, the number of the signal pulse that then count through the counter , latch with the latch the result of counting within standard time, use decipher display finally, number show is it is it come out to show to in charge of with LED result that latch. This article mainly narrated the digital frequency meter principle of work by and its each constituent. In this method , the Single - Chip Micro - computer AT89C52 is taken as a core part and it s three programmable timer/ counters are well used and the algorithm for measuring the waveshape period of N signals is also employed.

Key Words :  Frequency - counter ; Single - Chip Micro - computer

摘要 2
Abstract 3
引言 4
 第一章 测量原理 5
1.1计数式直接测频 5
1.2计数式直接测周期 6
1.3计数式测量时间间隔 7
1.4设计设计方案选择 9
1.5测量方法实现 10
1.6基本性能与指标 10
1.6.1基本要求 10
1.6.2发挥部分 11
第二章 总体方案设计 12
2.1输入电路设计 12
2.2分频器电路和三态门电路设计 14
2.3基准信号源 16
2.4　单片机电路 17
2.4.1时钟和复位 17
2.4.2 定时/计数功能 18
2.4.3 LED的驱动电路 19
第三章 软件设计 21
3.1频率的测量 21
3.2周期测量 22
3.3 脉宽测量 22
3.4占空比测量 22
第四章 误差分析 23
第五章 简易的数字频率计的实际情况 24
第六章 结论 25
致谢 26
参考文献 27

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