毕业论文--基于单片机的信号发生器的设计_精品.doc

CHANGZHOU INSTITUTE OF TECHNOLOGY 毕 业 设 计 说 明 书 题目：基于单片机的信号发生器的设计 二级学院： 专 业： 班级： 学生姓名： 学号： 指导教师： 职称： 评阅教师： 职称： 2013 年 6 月 摘 要 在科学研究、工程教育及生产实践中,我们经常会用到低频信号发生器，而且，随着信息技术的不断发展，信号发生器也在不断得进步，现在的信号发生器体积越来越小、功能越来越强、功耗越来越低、体积越来越小，在我们生活中的各个领域都得到了广泛的应用。 信号发生器即简易函数信号发生器，可以产生多种波形，如三角波、锯齿波、方波、正弦波等。本文通过分析函数信号发生器进行原理和构成，设计出产生三角波、锯齿波、方波、正弦波的函数信号发生器。 所设计的函数信号发生器以单片机(AT89C51) 系统为控制中心，由晶体振荡电路、地址产生电路(直接数字频率合成DDS)、波形产生电路、控制电路及串行通讯电路组成。本文采用了直接数字频率合成技术，较大幅度的提高了输出波形的频率，可满足输出频率20Hz-2MHz 的变化范围；采用串行通讯电路可以直接方便的通过上位机改变波形的频率,确定输出波形的类型。 关键词：函数信号发生器，AT89C51，DDS，直接数字频率合成 Abstract In our scientific research, engineering, education and production practice, we often need to use low frequency signal generator, and, with the development of information technology, the signal generator is also in constant progress, volume and signal generator now smaller, more powerful, more and more low power consumption, the volume is more and more small, each field in our lives are widely used. Signal generator is a simple function signal generator, can produce a variety of waveforms, such as the triangle wave, sawtooth wave, square wave, sine wave. Through the analysis of the principle and constitute the function signal generator, can be designed to generate triangle wave, sawtooth wave, square wave, sine function signal generator. The combination of circuit to generate waveforms using AT89C51 MCU and DAC0832 digital-to-analog converter, this method is used in software filter, harmonic component and therefore would not produce spurious, the generated waveform of relatively pure. But it also has some advantages such as: low cost, high performance, stability of waves used in this way in the low frequency range, easy operation, small size, less power consumption etc.. AT89C51 single-chip microcomputer as the core, the DAC0832 d/a co