基于单片机数字频率计的设计本科毕业的设计.doc

本 科 毕 业 设 计 基于单片机数字频率设计 Research and design of Based on single chip microcomputer digital frequency 学 院： 电子工程学院 专业班级： 电子信息工程 电子091班 学生姓名： 学 号： 指导教师： （高级实验师） 年 6 月 毕业设计中文摘要 摘要:作为基本的参数的频率决定了电参数量的许多的测量和结果， 因此,频率测量对我们来说有重要意义。测量频率的方法有很多种, 其中具有使用方便、测量迅速, 以及便于实现测量过程自动化等优点的电子计数器测量方法 可以作为频率测量的重要手段。现在普及的测量频率的的方法有两种, 直接测量频率的方法和间接测量频率的方法 （周期测频法）如果需要测量频率高的信号的话我们用直接测量方法, 如果要测量频率低的信号可以用间接测量的方法 。 本次的测频设计系统采用了以单片机AT89C52为核心的数字频率计进行，介绍了单片机控制，信号产生，数据选择器选择和LED的显示组成等，由信号发生器，过零电路，数字时钟信号分别产生频率，然后通过数据选择器选择，将被测的信号输送到微计算机中，通过程序控制数字时钟信号发生器计数，频率送至数据选择器74LS153和收发器74LS245,驱动LED数码管显示频率值并分析了测量误差并且说明方法来减小误差。 关键词:单片机;数字频率计;测频;误差 毕业设计外文摘要 Abstract: as the basic parameter of the frequency determines the electrical parameter measurement and the results of many of the quantity, so frequency measurement is important for us. Frequency measurement method has a lot of kinds, which is easy to use, measurement quickly, as well as the advantages of easy to realize automatic measurement process of the electronic counter measurement method can be used as important means of frequency measurement. Now popular method of measuring frequency has two kinds, direct measuring method and indirect method of measuring frequency of frequency (cycle) frequency measurement method for measuring high frequency signal words we use direct measurement method, if want to low frequency signal can be measured in indirect measurement method. The design frequency measurement system USES a single-chip computer AT89C52 as the core of digital frequency meter, and introduces the single-chip microcomputer control, data selector to choose and LED display, etc., will be measured signals to the microcomputer, the counting by program control digital clock signal generator, frequency selector 74 ls153 and sent to the data transceiver 74 ls245, drive LED digital tube display frequency values and analyzes the error of measurement and description methods to reduce err