基于单片机的数字频率计的设计与实现.doc

哈尔滨工业大学工学硕士学位论文- PAGE II --基于单片机的数字频率计的设计与实现摘要随着电子信息产业的发展，信号作为其最基础的元素，其频率的测量在科技研究和实际应用中的作用日益重要，而且需要测频的范围也越来越宽。传统的频率计通常采用组合电路和时序电路等大量的硬件电路构成，产品不但体积较大，运行速度慢，而且测量范围低，精度低。因此，随着对频率测量的要求的提高，传统的测频的方法在实际应用中已不能满足要求。因此我们需要寻找一种新的测频的方法。随着单片机技术的发展和成熟，用单片机来做为一个电路系统的控制电路逐渐显示出其无与伦比的优越性。本文阐述了以AT89C51单片机为控制器件的频率测量方法，并用汇编语言进行设计，采用单片机智能控制，结合外围电子电路，用以实现高低信号频率的测量。本文设计的是一个简易数字频率计，被测信号可以是正弦波、三角波、方波。首先，我们把待测信号经过放大整形；然后把信号送入单片机的定时计数器里进行计数，获得频率值；最后把测得的频率数值送入显示电路里进行显示。本文从频率计的原理出发，介绍了基于单片机的数字频率计的设计方案，选择了实现系统得各种电路元器件，并对硬件电路进行了仿真。关键词　单片机；频率计；测量Design and implementation of Digital Frequency Meter Based on Single Chip MircrocomputeAbstractAlong with the development of electronic information industry, signal as the basic elements, the frequency measurement in scientific research and practical application is increasingly important, but also need the scope of frequency measurement is becoming more and more wide. The traditional frequency plan usually adopts combinational circuits and the sequential circuits of the hardware circuit structure, product not only large size, speed is slow, and measuring range, and low accuracy of low. Therefore, as for frequency measurement requirements, the traditional method of frequency measurement in practical application already cannot satisfy requirements. Therefore, we need to find a new measuring method of frequency. Along with the development of technology and mature, use a singleship as a circuit system of control circuit shown its incomparable advantages.In this paper, with AT89C51 microcontroller to control the frequency of measurement devices and assembly language design, intelligent control using single chip, combined with the external electronic circuit, can be high and low frequency measurements. This paper designs a simple digital frequency, the measured signal can be sine wave , square wave. Firstly, the rectangular pulse, which the measured signal is amplified and reshaped, is used as control throttle valve. Then, the frequency counter counts the number