一种基于PIC单片机的多功能测频系统

频率作为电子技术的基本参量，其测量结果的准确性成为衡量一个以频率作为技术指标之一的待测电子系统是否达到设计要求的关键因素。PWM（脉宽调制）信号是现代电子技术当中广泛应用的一类重要数字信号，对这种信号的表征除了频率本身外，还有周期、脉宽、占空比等其它技术特征。传统频率计一般只能测量和显示频率单一参数，对PWM信号的其他参量无法进行测量。随着电子技术的迅速发展，以单片机为控制核心的控制器件，已经全面渗透到测试仪器和计量检定的各个方面，成为应用的热点。本文提出并设计了一种以PIC单片机CCP模块为核心，以差分信号为基础的多功能数字频率计，克服了传统测频方法的不足，有效地实现了PWM信号各种技术指标的同步测量。同时，系统还具备硬件结构简单，软件算法容易实现的优点，便于工程上的实际应用。

A multifunctional measurement system for frequency based on PIC microprocessor

Frequency is the basic parameter of electronic technology, the accuracy of the measurement results becomes ：he key factor which judges whether a electronic system matched the design requirements. PWM signal is one of impor-tant digital signals widely used in modem electronics. In addition to frequency ,the period ,pulse width and duty cycle are all the features of PWM signal. Tranditional frequency meters can only measure and display frequency, lack the abil-ity to measure other parameters of PWM signal. With the rapid development of electronic technology, the control devices based on MCU have been fully penetrated into the measurement equipments and become the hot point in applications. In this paper, we proposed and designed a multifunctional frequency meter based on differential signal and the CCP module of PIC MCU. This design overcomes the deficiencies of traditional frequency measurement method , and effectively a-chieves the synchronous measurement for various technical parameters of PWM. The system has advantages of simple structure and being easy to implement in software algorithm, which takes convenience to practical applications in engi-neering.