基于单片机的数字频率计设计

摘要

基于单片机的数字频率计的设计，目的是设计一款数字频率计，能够测量1Hz-20MHz的数字频率，包括三角波、正弦波及方波的测量，支持0．5V-20V电压。本频率计的特点是突破普通单片机频率计喜欢选用的直接测量法，选择了高频用多周期同步法，低频用周期法来测量频率。这样可以使频率计达到更高的精度。而且本频率计通过程序来控制分频芯片自动分频，无需测量者对信号进行预估计，超出测量范围会自动警报，更加人性化。%The topic of this paper is digital frequency meter design based on SCM, the purpose of which is to design a digital fro- quency meter to measure 1 - 20 MHz digital frequency, including the measurement of triangular, sine and square wave, and support 0.5 V - 20 V voltage. The characteristics of this kind of frequency meter is a breakthrough in SCM frequency meter with the direct measurement method, chooses the synchronization method with high frequency and the low frequency with period method to measure the frequency. This can make it to achieve better frequency accuracy. And this frequency plan controls the fractional frequency chip through the program to automatically divide frequency, without estimate the signal beforo measurement and ff beyond measurement range, it will automatieally make alarming.