介绍了以AT89C2051单片机为核心的智能频率计的设计，利用单片机内部的定时(计数)器完成待测信号周期(频率)的测量。对系统的信号预处理电路、控制电路和显示电路三大部分进行了研究，采用RS232接口电路，利用VB6编程语言实现了PC机串口接收控制程序。-Introduced a single chip AT89C2051 frequency as the core of intelligent design, the use of single-chip internal timer (cou

ket noi giua rs232 va vb6

giao tiep ket noi giua rs232 va vb6