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陕西理工学院毕业设计第1页共65页基于单片机的交流信号源的设计范鹏兴（陕理工机械工程学院机自专业087班，陕西汉中723003）指导教师：王长乾[摘要]本设计使用51单片机对DDS芯片进行控制，利用DDS造波的方法产生需要的正弦信号.用户可以根据需要对芯片设定一个频率值或相位值,通过单片机传输芯片控制字对芯片输出的频率和相位进行调节,达到用户所要求的信号。本设计采用模块化设计的方法，不同的模块为实现不同的功能而设计，总体由单片机控制协调工作。利用51单片机控制DDS芯片造波，具有如下优越性：1.造价低廉。51系列单片机应用广泛，价格低廉，比较容易购买，DDS芯片价格较单片机稍高，但与价格成百上千的成品信号发生器相比，本设计经济优势显著。2.电路简单。本设计利用单片机进行数字化控制，外围元件较少，仅需辅以少量的阻容元件用于电流电压匹配控制以及滤波电路既可。3.频率控制准确高效。数字化控制的最大优点即控制准确。本设计选用的DDS芯片内置32位高速数模转换器，分辨率高，响应快。[关键词]51单片机；DDS造波；频率;TheDesignofSinusoidalSignalGeneratorBasedonSinglechipFanPengxing(Grade08,Class7,Majormechanicalengineering，MechanicalengineeringandautomationDept.，ShaanxiUniversityofTechnology，Hanzhong723000，Shaanxi)Tutor:WangChangqian[Abstract]:Thedesignuse51series’singlechiptocontrolDDSchip’sworking.UsingDDSmethodtoproducesinesignal.Theusercansetafrequencyorphasevaluefreely.Toachievetheuserrequestsignal,thesinglechipneedsendingacontrolwordtoDDSchip,whichdeterminesthefrequencyandphasevalues.Thisdesignusesthemodulardesignmethod,differentmodulesdesignedfordifferentfunctions.Singlechipresponsibleforcoordinationofallwork.ThebenefitsofDDSmethodtoproducesinesignalasfollows:1.lowcost.The51series’singlechip’sapplicationarerange,sotheyhavelowpriceandareeasytopurchase.ThepriceofDDSchipisslightlyhigherthansinglechip.buttocomparewiththecommoditysignal陕西理工学院毕业设计第2页共65页generatorwhichvalueshundredseventhousands,theadvantagesofthisdesignisobvious.2.Simplecircuit..BenefitswhichdigitalcontroltakesisPeripheralelementisless.It’sonlyneedafewcapacitanceandresistanceelementforcrrentandvoltagematchingandfilter.3.Frequencycontrolisaccurateandefficient.Frequencycontrolisaccurateandefficient.ThisdesignusingDDSchipwith32bithighspeedD/Aconverter,whichhasahighresolution,fastresponse.[Keywords]:51singlechip;DDSmethodtoproducesignal;Frequency;陕西理工学院毕业设计第3页共65页目录TheDesignofSinusoidalSignalGeneratorBasedonSinglechip.......................................1引言..............................................................................................................................51绪论..........................................................................................................................61.1单片机在函数信号发生器中的应用............................................................................61.2发展现状.........................................................................................................................61.3项目可行性研究.............................................................................................................61.4设计任务和要求.............................................................................................................72.方案及工作原理.......................................................................................................72.1方案设计.........................................................................................................................72.1.1方案一..........................................................................................................................72.1.2方案二.........................................................................................................................72.1.3方案三.........................................................................................................................72.1.4方案四.........................................................................................................................72.2DDS工作原理................................................................................................................82.3DDS移相原理................................................................................................................83.电路设计...................................................................................................................93.1设计思路.........................................................................................................................93.2元件选型.........................................................................................................................93.3系统总体框图.................................................................................................................93.4STC89C52RC单片机...................................................................................................103.5AD9850芯片................................................................................................................113.5.1AD9850芯片简介.....................................................................................................113.5.2AD9850工作方式介绍.............................................................................................123.5.3相位控制字的计算....................................................................................................123.61602LCD显示屏..........................................................................................................133.6.1液晶概述....................................................................................................................133.6.2接口信号说明...............................