毕 业 论 文（设 计）
题 目 基于单片机的频率计设计 英文题目 The design of frequency meter
based on single chip
院 系 专 业 姓 名 年 级 指导教师
年 月
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摘 要
频率计，也称为频率表或电子计数器。它不仅是电子测量和仪表专业领域中测量频率与周期、测量频率比和进行计数、测时的重要仪器，而且要比示波器测频更方便、经济得多，特别是现代电子计数器产品与组件和具有多种测量功能的数字频率计，已广泛应用于计算机系统、通讯广播设备、生产过程自动化测控装置、带有LED、LCD数字显示单元的多种仪表以及诸多的科学技术领域。可以说伴随着数字化技术的发展，电子计算机、通讯设备、音频和视频技术进入科研、生产、军事技术和经济生活领域，直至家庭和个人，使得电子计数器和测频手段与上述电子设备耦连为形影不离的技术。
以单片机AT89C51为核心设计了一种频率计。在设计中应用单片机的数学运算和控制功能，克服了一般数字频率计在低频精度不高的缺点；频率计首先以单片机内部的定时/计数器产生1S定时作为控制闸门信号，然后把被测信号放大整形后的方波脉冲信号的周期作为计数，从而求得被测信号的频率值，最后通过八位动态显示电路显示数值。电路主要由以下三部分组成：a.AT89C51单片机。它是频率计的核心，大部分工作由它完成；b.放大整形电路。为频率测量作好准备；c.显示电路。用于显示频率值。
关键词：单片机；频率计；显示
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The design of frequency meter based on single chip
Abstrac Frequency, also known as frequency counter or electronic form.
It is not only electronic measurement instruments and professional in the field of measuring frequency and the cycle than the frequency of measurement and counting, the important measurement instruments, oscilloscopes and measuring frequency than more convenient, more economic, especially the modern electronic counter products and components And a variety of measurements of the digital frequency, has been widely used in computer systems, radio communication equipment, automated production process measurement and control devices, with LED, LCD modules figures show that the number of instruments and many scientific and technical fields. It can be said that along with the development of digital technology, computers, communications equipment, audio and video technology into the research, production, military technology and economic spheres of life, until the families and individuals, making electronic means of measuring frequency counter and the electronic equipment and even for the decoupling Inseparable technology.
I have designed one kind of frequency meter which regarded Single-Chip Microcomputer AT89C51 as the core.The mathematical operation of applying in designing Single-Chip Microcomputer and controlling the function, has overcome the general digital frequency meter in the shortcoming not high of the precision of low frequency; frequency meter at first with timing of Single-Chip Microcomputer / counter 1S produces as controlling the gate signal regularly.Then examine signal is it have a facelift square wave cycle conduct of pulse signal after count to amplify, is it examine into frequency value of signal to try to get , show through 8 circuit display number value dynamically finally.The circuit is made up of three following parts mainly: a.AT89C51 Single-Chip Microcomputer. It is a core of the frequency meter, most work are finished by it; b.Enlarge and have a facelift the circuit. Prepare for frequency measurement; c. the display circuit. Used for showing frequency value.
Key Words: Single-Chip Microcomputer; Frequency Meter; Display