摘 要
在电子技术领域内，频率是一个最基本的参数，频率的检测与许多电气参数的测量都有着十分密切的关系。因此，频率的测量就显得更为重要。
本论文主要介绍频率计的硬件结构和软件设计。硬件部分通过采用AT89C2051单片机构成核心控制电路，在设计中，使用AT89C2051的P1.0口作为待测频率信号的脉冲输入计数部件，定时器T1用来对脉冲信号的周期进行计数，测量结果以十进制数在4位LED数码管上显示。软件设计采用模块编程的方法来实现，主要完成频率测量及结果显示。设计过程中使用到的工具有Protel和Keil uVision2。
许多出口的电器设备的性能必须在60Hz交流电源下测试，为了监视60Hz交流电源的频率，就必须要用频率计。针对这个问题，本课题设计了一台专用频率计，频率测量范围在20.00Hz~99.99Hz。
关键词：频率计；单片机；AT89C2051
ABSTRACT
In the field of electronic technology, the frequency is basic parameter, Frequency of Detection and many of the measurement of electrical parameters have a very close relationship. Therefore, the measurement of frequency is even more important. This paper introduces the hardware and software design of frequency meter. The part of hardware constitute the core control circuits adopted AT89C2051. This design uses P1.0 of AT89C2051 as the pulse input counting parts of analytic signal frequency. The timer of T1 is used to count the signal pulse cycle. The results of measurement display in the 4 LED digital tubes with a decimal number. The design of software is achieved with the method of Programming Module, and to achieve the measurement of frequency and display the results. Protel and Keil uVision2 are used in the design process.
The performance of many electrical types of equipment which exported should be tested under the 60 Hz AC power. We must use frequency meter to monitor 60 Hz frequency AC power. To this issue, the task designs an exclusive frequency meter, the range of frequency measurement in 20.00 Hz ~ 99.99Hz.
Keywords: frequency meter； single chip processor ；AT89C2051
