基于单片机的DDS函数信号发生器

广西师范大学2011届本科生毕业论文（设计）本科毕业论文设计基于单片机的DDS函数信号发生器题目：专业名称：学生姓名：学生学号：指导老师：毕业时间：广西师范大学2011届本科生毕业论文（设计）II【内容摘要】信号发生器常被用来当作信号发生源，它可以产生多种波形,如三角波、锯齿波、矩形波（含方波）、正弦波，并且各波形的幅度和频率可调，正是因为信号发生器可以产生各种波形的信号，因此在在电路实验和设备检测生产实践和科技领域中都有着广泛的应用。本系统主要包括四个部分，电源供电，单片机最小系统，DDS，显示。本系统主要用89C52单片机与DDS器AD9833构成的函数信号发生器，可产生方波、三角波、正弦波，可以由程序控制改波形的周期，并可以通过按钮实现不同波形切换。DDS输出信号的幅值为0-2.5V，频率步进1KHz可调，实际信号频率通过4位数码管显示。对于输出信号幅值的控制，主要是用OP07放大器对其信号放大来实现的。通过OP07放大器可以把DDS输出信号的幅值放大2倍，从而达到了输出波形幅值在0-5V变化。【关键词】：AD9833；89C52；DDS；信号发生器广西师范大学2011届本科生毕业论文（设计）IIIABSTRACTPlacingsignageatsignalgeneratorisoftenusedasasignal,itcanproducevariouswaveform,suchastrianglewave,sawtoothwave,rectanglewave(includingsquarewave),sinewave,andthewaveamplitudeandfrequencyadjustable,itisbecausethesignalgeneratorcanproducevariouswaveformsignal,thereforeincircuitexperimentandtestequipmentinthefieldofproductionpracticeandscienceandtechnologyhasawiderangeofapplications.Systemmainlyincludesfourparts,powersupply,singlechipmicrocomputerminimumsystem,DDSconversion,display.ThissystemmainlyUSESthe89c51andconstituteoftheDDSconverterAD9833functionsignalgenerator,canproducesquarewave,trianglewave,sinewave,canbecontrolledbytheprogramtochangethecycleofthewaveform,andcanimplementdifferentwaveformbypressingthebuttonswitch.Outputsignalamplitudeof0-2.5V,step1KHZfrequencyisadjustable,theactualsignalfrequencythroughthefourdigitaltubedisplay.Forcontroloutputsignalamplitude,mainistouseOP07amplifierforsignalamplification.ThroughtheOP07amplifiercanmagnifyDDSoutputsignalamplitude2times,soastoachievetheoutputwaveformamplitudechangesin0to5v.Keywords:AD9833；89C52；DDSconverter；signalgenerator广西师范大学2011届本科生毕业论文（设计）目录ABSTRACT........................................................................................................................................III1绪论...............................................................................................................................................11方案论证.........................................................................................................................................11.1单片机选择与论证.........................................................................................................11.2DDS选择与论证...........................................................................................................21.3显示模块...........................................................................................................................21.4输入按键......................................................................................错误!未定义书签。1.5、电源模块的选取..........................................................................................................42硬件电路设计................................................................................................................................42.1硬件设计总体框图.........................................................................................................42.2系统原理框图简介........................................................................................................52.3电源电路设计.................................................................................................................52.4单片机最小系统设计...................................................................................................72.4.1单片机主控电路..............................................................................................82.4.2单片机最小系统组成......................................................................................82.5DDS输出设计..................................................................................................................92.5.1芯片简介............................................................................................................102.5.2TL431简介....................................................................错误!未定义书签。2.5.3DDS信号发生器的组成...............................................................................102.5.4DDS原理及应用.............................................................................................102.6信号幅值放大............................................................................错误!未定义书签。2.6.1放大原理分析..............................................................错误!未定义书签。2.7.1数码管显示分析............................................................................................112.8按键电路.........................................................................................................................123软件设计.......................................................................................................................................133.1软件设计总流程图.................................................................................................................133.2波形输出软件设计......................................................................................................14广西师范大学2011届本科生毕业论文（设计）3.2.1DDS器软件设计..........................................................错误!未定义书签。3.2.2方波产生软件设计...............................................................................