基于单片机的频率测量仪的设计.pdf

要

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，测量频率范围为0.1Hz~5MHz。

关键词：计数法测宽法分频
Nowadays,electronictechnologyusheredinrapiddevelopment,andthefrequency
ofanelectronicelectricalengineeringasaveryimportantparameter,someasuring
frequencybecomesoimportant.Meanwhilefrequencymeteriscomputers,
communicationsequipment,audioandvideoandotherresearchareasindispensable
measuringinstruments.Togetbetterperformanceofelectronicsystems,aprecision
frequencymeterisessential.
ThispapermainlydiscussesSTC89C52microcontrollerbaseddesigndigital
frequencymeter,widemeasuringrange,frequencyresponserange,measurementspeed,
smallsize,highaccuracy.Itmainlyconsistsofalow-passfiltercircuit,zero-crossing
comparatorcircuit,frequencydividercircuit,MCUprocessingcircuit,themeasurement
resultsdisplaycircuit.Canautomaticallydetectmeasurementfrequencyswitchinggear,
high-frequencydividerwhenthecountingmethodusedtoimprovetheaccuracy,wide
measurementfrequencywhenusingthemethodoffrequencymeasurementto
measurementtimeasshortaspossible.Itcanmeasurethesignalsquarewave,triangle
wave,sinewave,sawtoothandotherkindsofsignals,themeasurementfrequencyrange
of0.1Hz~15MHz.

Keywords:CountingmethodWidthmeasurementmethodfrequencydividing
0.1Hz~15MHz
录i

录

第一章绪论.....................................................................................................................1
1.1课题背景.............................................................................................................1
1.2频率计目前发展概况.........................................................................................1
1.3课题研究目的及意义.........................................................................................2
1.4数字频率计设计任务与要求.............................