编号：课程设计说明书题目：基于DDS的信号发生器院（系）：信息与通信学院专业：电子信息工程学生姓名：峰之使者学号：指导教师：2014年12月21日摘要随着信息技术的发展，现代电子系统对波形发生器提出了更高的要求。直接数字合成（DirectDigitalSynthesize，DDS）是一种重要的频率合成技术，具有分辨率高，频率变换快等优点。利用键盘输入波形频率，存入单片机，通过单片机控制诺基亚5110液晶屏，让诺基亚5110液晶显示输入频率的大小。再通过单片机控制AD9851，再经过AD9851内部的相位累加器、相位寄存器、正弦查询表、DAC转换器、内部低通滤波器，然后经低通滤波器后，可输出正弦波,外接一个高速比较器，可以输出方波,通过调节一个滑动变阻器，改变方波的占空比，为了克服有线连接繁琐的缺点，利用了无线模块NRF24L01进行数据传输，通过数据通信，可以远距离控制。关键词：DDS；单片机；AD9851；无线模块NRF24L01；AbstractWiththedevelopmentofinformationtechnology,modernelectronicsystemputsforwardhigherrequirementsonwaveformgenerator.Directdigitalsynthesis（DirectDigitalSynthesize，DDS）isanimportantkindoffrequencysynthesistechnology,withhighresolution,frequencyconversionfast,etc.Usingthekeyboardinputwaveformfrequency,depositedinthesinglechipmicrocomputer,throughsinglechipmicrocomputercontrolthenokia5110LCDscreen,letnokia5110LCDdisplaysthesizeoftheinputfrequency.IscontrolledbysinglechipAD9851,thenthroughAD9851internalphaseaccumulator,phaseregisters,sinelookuptable,DACconverters,internallowpassfilter,andthenafterlowpassfilter,outputsinewave,externalahigh-speedcomparator,canoutputpulse,byadjustingasliderheostat,changethedutycyclesquarewave,wiredconnectiontrivalinordertoovercometheshortcomings,theuseofthewirelessmoduleNRF24L01fordatatransmission,throughthedatacommunication,remotecontrol.Keyword：DDS;Entirenumericalcontrol;Monolithicintegratedcircuit;wirelessmodule;目录引言......................................................................11任务要求与设计的背景.....................................................11.1设计任务要求...........................................................................................................................................11.2课题背景...................................................................................................................................................11.3直接数字频率合成技术的现状...............................................................................................................12系统总体方案的分析和设计................................................22.1DDS技术的基本原理..............................................................................................................................22.2DDS的工作特点......................................................................................................................................32.3系统设计原理...........................................................................................................................................32.4系统框图分析和设计...............................................................................................................................43系统的硬件设计..........................................................43.1单片机最小系统.......................................................................................................................................43.1.1时钟电路....................................................................................
