超低频波形发生器的设计论文(C语言编程) .doc

摘 要

在科学研究、工程教育及生产实践中,常常需要用到低频信号发生器。本文主要介绍一种以单片机为核心超低频任意函信号发生器。该信号发生器、、、采用数字波形合成技术,通过硬件电路和软件程序相结合,可输出自定义波形,如正弦波、三角波、方波和锯齿波及其他任意波形。详细介绍了硬件电路设计软件。波形的频率和幅值在一定范围内可任意改变与传统信号发生器只有固定的几种输出波形相比,具有输出波形的任意化和低频精度高的特点,在低频范围稳定性好、操作方便、体积小、耗电少等。

关键词：单片机AT89C51； DAC0832； 低频信号； 发生器

ABSTRACT

In scientific research, engineering education and practice of production, often need to use low-frequency signal generator. In this paper, introduces a ultra-low frequency arbitrary function signal generator to SCM as the core. The signal generator is made of the memory modules, the key modules, LED display modules, D/A converter modules,it uses date waveform synthesis technology,through hardware Circuit and software Procedures is combined,custom Waveform can be customized, such as sine wave, triangle wave, square wave and sawtooth wave and other arbitrary waveform. In this paper ,detail introduces the principle of the design of hardware circuit and the mind of the design of software programming and the process of experiment debug.The results of experiment show that,the output waveform′s frequency and amplitude of the signal generator can be arbitrarily changed in a certain range,compared With the traditional signal generator Only have a few fixe output waveform,with the characteristics of output waveform′s arbitrary and high precision of the low-frequency. It also has the characteristics of a low price, high-performance, good Stability in low-frequency range, easy to operate, small size, less consumpte of power Etc..

Key words：AT89C51 microcontroller； DAC0832；Low frequency signal； Generator

前言

信号发生器是使用很广的仪器, 在科学研究、工程教育及生产实践中,常常需要用到低频信号发生器。如工业过程控制、教学实验、机械振动、生物医学等领域。对它的要求也随着技术的发展越来越高,以往的信号源只可输出单一正弦或几种如三角、正弦、脉冲、方波等波形,且一台仪器的输出频率范围也较窄,一般只是在超低或低频范围, 特别是在超低频范围, 波形的精度和稳定度等重要指标都不高,目前,长期使用的信号发生器绝大部分都是由模拟电路构成的,这类仪器作为信号源,频率达百兆赫兹,在高频范围内其频率稳定性与可调性好。而用于低频信号输出时,其需要RC 值很大,参数准确度难以保证,而且体积大,损耗也大。目前,有人研究制造了由数字电路构成的低频信号发生器,其低频性能好,但是体积较大,价格较贵。这里介绍一种以单片机为核心,设计了一个超低频任意函数信号发生器。,由于采用直接数字波形合成技术,频率准确度和稳定度较高。与现有采用计数器、只读