基于单片机的数字滤波器设计

基于单片机的数字滤波器设计I基于单片机数字滤波器设计摘要数据采集又称数据获取，是利用一种装置，从系统外部采集数据并输入到系统内部的一个接口。数据采集技术广泛应用在各个领域。比如摄像头，麦克风，都是数据采集工具。被采集数据是已被转换为电讯号的各种物理量，如温度，水位，风速，压力等，可以是模拟量，也可以是数字量。在互联网行业快速发展的今天，数据采集已经被广泛应用于互联网及分布式领域，数据采集领域已经发生重要变化。而在数据采集中存在各种噪声。滤除噪声的方法有很多种，既有数字滤波器，也有模拟滤波器。本文采用了基于单片机和c语言来设计并开发数字滤波系统。针对于单片机数据采集系统中经常出现的随机干扰，通过交流信号发生器输入来模拟数据采集过程，验证了几种使用较为普遍的克服随机干扰的单片机数字滤波算法，并给出了相应的c程序，同时也对这几种滤波算法进行了比较，并指出每一种算法具体适用范围和注意事项。另外本文使用了proteus进行仿真验证这几种滤波方法，用了AD和DA来采集及输出数据。关键词单片机/proteus/数字滤波。基于单片机的数字滤波器设计IIBASEDONSCMDIGITALFILTERDESIGNABSTRACTDataacquisition,alsocalleddataacquisitionistheuseofadevicefromthesysteminputtoexternaldatacollectionandaninterfacethatinternalsystem.Datacollectiontechnologyiswidelyquotedinvariousfields.Suchascameras,microphones,aredataacquisitiontools.Arecollecteddatahasbeenconvertedtotelecommunicationsnumberofvariousphysicalquantitiessuchastemperature,pressure,water,windspeed,etc,canbeanalogue,alsocanbethedigitalquantity.IntheInternetindustryfastdevelopmenttoday,dataacquisitionhasbeenwidelyusedinInternetanddistributedfield,dataacquisitionfieldhaschangedinimportantchanges.Andindataacquisitionexistinallsortsofnoise.Filteroutthenoiseavarietyofways,bothdigitalfilters,alsohavesimulationfilter.HereweadoptedbasedonSCMandClanguagetodesignanddevelopdigitalfilteringsystem.Webasedonsingle-chipmicrocomputerdataacquisitionsystemoftenappearsintherandomdisturbance,throughthemanualinputtosimulatedataacquisitionprocess,andverifiestheseveralusecommonovercomerandomdisturbancesingle-chipdigitalfilteringalgorithm,andpresentsthecorrespondingCprogram,especiallyforthemedianvaluefilterandthemedianvalueaveragefilteringalgorithmprocedureswereimproved.Alsoonthiscomparesseveralfilteringalgorithm,andpointsouttheconcreteeachkindofalgorithmisapplicablerangeandprecautions.Inadditionweusethesimulationtestthisproteusseveralfilteringmethod.InadditionwestillusetheADandDAtoharvestandoutputdata.KEYWORDSmicrocontroller,proteus,digitalfilter基于单片机的数字滤波器设计III目录摘要...................................................................................................................................................IABSTRACT......................................................................................................................................II1绪论................................................................................................................................................11.1数字滤波器特点...........................................................................................................11.2数字滤波器的设计......................................................................................................22数字滤波设计原理...................................................................................................................32.1中值滤波...........................................................................................................................32.2算数平均滤波.................................................................................................................42.3加权平均滤波................................................................................................................52.4中位值平均滤波...........................................................................................................62.5限幅滤波...........................................................................................................................73滤波器硬件设计........................................................................................................................83.1单片机AT89C51............................................................................................................83.2数据采集...........................................................................................................................93.3数模转换输出..............................................................................................................103.4总体电路图...................................................................................................................104程序设计......................................................................................................................................114.1滤波算法设计..............................................................................................................114.2AD转换器.......................................................................................................................12基于单片机的数字滤波器设计IV4.3滤波算法的选择.........................................................................................................124.4总体程序.........................................................................................................................134.5程序流程图...................................................................................................................135仿真结果和分析......................................................................................................................146数字滤波器新算法分析...........................................................................................