基于单片机的频率计数器的设计

研制开发一种采用微机技术的单片机频率计数器，该频率计首先以被测信号放大整形后的方波脉冲作为控制闸门信号，然后采用单片机内部的定时器计数器对脉宽的机器周期数进行计数，从求求得被测信号的频率值，最后通过静态显示电路显示数值，由于单片机内部振荡频率很高，所以一个机器周期的量化误差相当小，可以有效地提高低频信号的测量准确性。

Design of Singlechip-based Frequency Counter

The conventional frequency counter usually consists of a large number of hardware-based electric circuits, such as combined and time-serial electric circuits.lt is bulky and slow.Considering the shoftcomingsabove, this paper develops a kind of singlechip-based frequency counter using micro-computer techniques.Firstly, the rectangular pulse, which the measured signal is amplified and reshaped, is used as control throttlevalve. Then, the frequency couflter counts the number of the periods using the internal timer/counter of singlechip so as to gain the frequency value of measured signal. Finally, the frequency value of measured signal isdisplayed through static display circuits. Since the internal oscillation frequency ofsinglechip is very high, themeasured error in one period is very small, and the measuring accuracy of low frequency signal can be effectively improved.