基于单片机的汽车防盗报警系统设计中英文参考资料Word文档下载推荐.docx

基于单片机的汽车防盗报警系统设计中英文参考资料Word文档下载推荐.docx

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Decodestheautomobilesecuritysystemusingthemonlitchisintegratedcircuitinteriorresourcesrealizationjumpcode,iteachtimeusestheremotecontrolpasswordallischanging,bothenhancedthesystemsecurity,andgreatlyreducedthecost.

Keyword:

Monolithicintegratedcircuit,Automobilesecuritysystem,Code/decode

Introduction

Isunceasinglyprogressivealongwiththesocialeconomyandthehightechrapiddevelopment,intheroutineworkandthelife,theautomobilehasbecomethepeopleidealtransportationvehicle.Butthefollowingmotorvehiclethecasewhichrobbedgraduallyisalsoincreasedhascreatedthepiloteconomicalpropertyloss.Inordertoreducetheautomobiletorobtheeventtheformationrate,forhastheautomobiletheusertoprovidethesafetycontrol,simplydevelopsonekindtobereliable,theeaseofoperation,cansendoutinthediscoverynormalconditiontothepilotreportstothepolicethereminderandthesecuritywarningsafetysystemhasthepracticalsignificance.Thisarticlebasedontotheexistingautomobilesecurityalarmsystemgeneralizedanalysis,developsonekindofbrand-newsecurityalarmsystem.Thissystemhasmainlyusedthejumpcodecode/decodingprinciple,causestheoverallsystemtobesafer,greatlyreducespasswordexplainingrate.

1.Systemprincipleofwork

Theautomobilesecurityalarmsystemtheremotecontrolwhichcarriesbythedriverandinstallsintheautomobilethecontrollertwopartscomposes.TheremotecontrolandthecontrolleralluseeightCMOSwhichAmericanAT-MELCorporationproducestheAVRmonolithicintegratedcircuit,thisseriesmonolithicintegratedcircuitbasedonnewsimplifiesinstructionRtheISCstructure,includestheservicelifemosttobefewis1,000timewrites/scratchesthecirculationtheFlashprogrammemory,aswellastheservicelifeatleastis100,000timewrites/scratchesthecirculationEtheEPROMdata-carrierstorage,some2onlyhavewhentheentirepiececleaningcancleantheprogrammingencryptionlocksthelocalization.

1.1Systemdesign

Theautomobilesecurityexaminationusestheultrasonicsensor.Theultrasonicsensoriscomposedbytheultrasonicwavetransmissioncircuitandthesupersonicreceptionelectriccircuit,intheautomobilecabappropriateposition,installstheultrasonicwavelaunch/receiver,aswellasswitchelectriccircuitT1.Whentheautomobileparksthevehicleownerpersonmustleavetheautomobile,withremotecontrolclosedswitchT1,theautomobilealarmsystemsatgarrisonsthecondition,aroundthesystemuseultrasonicwaveexaminationvehicleobstacle.Launchesthepartialelectriccircuitslikeschart1toshow.WhenitsP1mouthP1.1,P1.2totheDtrig,theP1.0controlultrasonicwavelaunch,are0,thephotoelectricitycoupleroutputstheTP1endis1,thepermissionultrasonicwavelaunch,launches/thereceiveultrasonicwaveinturn,thecirculationrepeatedlycarrieson.Simultaneouslythemonolithicintegratedcircuitinteriorcounterstartstocount.Thesteamdistancebetweenvehiclesobstacledistanceisthetimewhichsendsoutthroughthesoundnavigationandrangingreflectsspendsdeterminesandcarriesonthecomputation.ThereflectionsignalcausestheDtriggertoproduceinterruptrequestsignalINT1,simultaneouslystopscounting,readstakescountsthevalue,calculatestheactualdistanceaftertheformula,thencarriesonthecomparisonwiththedatumdistance,ifexamineswhentheactualdistanceisbiggerthanreferencevalue80cm,doesnotcarryontheaccustom-opticstoreporttothepolice;

Ifsomepeopleapproachtheautomobiletoenterthecab,theexaminationactualdistanceissmallerthanorwasequaltowhenreferencevalue80cm,throughmonolithicintegratedcircuitP2.2andtheP2.3port,actuatestheindicatinglampdisplaycircuitandthesoundalarmcircuit,sendsoutthreetwoflash.Andtriggersahighlevel,theactuationiswirelesssignaltransmissioncircuit.

Chart1Ultrasonicwavetransmissioncircuit

1.2Code/decodingprinciple

ThepresentautomobileremotecontrolsecuritysystemaremanyisusesVD5026/27,PT2262/72,HT12E/Dandsoonthegeneralcode/decodestheelectriccircuit,itspassworddecidedbythecomponentaddress,eachsetofsecuritysystemsuseafixedinvariablepassword.Alongwiththemicroprocessingtechnologydevelopment,throughthereceiveremotecontroltransmittingmessage,mayinterceptthisfixedpassword,moreovergeneralarrangesthedecodingaddresstolosethepersontocarrythecomponentsizelimit,itsquantityisimpossibletoomuch,canobtainnotrepeatedlycodesveryisalsolimited,alsocanveryquicklyexplainthepasswordwiththeautomaticscanner.Therefore,thiskindofpasswordfixedinvariableautomobilesecuritysystemhasreceivedtheseriousthreat.Decodestheautomobilesecuritysystemusingthemonolithicintegratedcircuitinteriorresourcesrealizationjumpcode,iteachtimeusestheremotecontrolpasswordallischanging,withthepasswordnolongerduplicatesuses,causestheinterceptionpasswordalsoismakesafutileeffort,inaddition,itmayincreasetheenoughmanypasswordsfigure,enhancesthesystemresistanceillegalscanningtheability.Theremotecontrolcodingaltogetherhas12bytes,separatelyby3bytescodeschannelscode,3bytescodesforewordsnumber,5bytesjumpscodes,1bytepressedkeyoperationcodeiscomposed.Encodedfrontaddsonlogicineachbyte0totaketheoutsetposition,encodedbehindaddsonalogical1achievementineachbytetostoptheposition,andinmostfrontaddsonseverallogic1totaketheguidancesignal,thisconstitutedtheserialcodedsignalwhichusesintotransmit.Thecodechannelcodeusesintoexpresstheremotecontrolstatus;

eachsetofsystemsuseafixedchannelcode.Thecodeforewordnumberusesintorecordtheencodedorder,itsstartingvalueis0,themonolithicintegratedcircuiteverytimecodesatime,thecodeforewordnumberupwardlycountstime.ThecodechannelcodeandthecodeforewordnumberdepositsinmonolithicintegratedcircuitEEPROM,guaranteesthempowercuttheinfluence.Thejumpcodeisthesystematictruepassword,itpassesthroughthecomplexspecialalgorithmbythecodechannelcodeandthecodeforewordnumbertoextract,thisspecialalgorithmforeignsecurity.Thepressedkeyoperationcodebythepressedkeywhichpresseswasdecided,when"

thehypothesis"

thekeyispresseddown,itscodedecidesas01H;

When"

relieves"

thekeypressesdown,itscodedecidesas00H.Whetheristhedecodingconfirmsreceivethecodelegitimateaseriesofoperatingprocess.Wasconfirmedthelegitimatecodeneedstosatisfythreeconditions;

（1）codesthechannelcodeandthedecodingchannelcodeissame;

（2）codedtheforewordnumbertobebiggerthanthedecodingforewordnumber（decodingforewordnumbertorecordonlegitimatelyhasusedcodeforewordnumber,thisconditionmightguaranteebeforehasusedcodewasinvalid）;

（3）jumpsthecodetobeequaltoreusesthespecialalgorithmtoextractchangesthecode.Afterthemonolithicintegratedcircuitconfirmedreceivesisthelegitimatecode,writesthecodeforewordnumberinthedecodingforewordnumber,andcompletescorrespondingoperationprocessingaccordingtotheoperationcode.ThedecodingchannelcodeandthedecodingforewordnumberalsodepositsinmonolithicintegratedcircuitEEPROM,guardsagainstbecauseofpowercutloses.

1.3Securityreportstothepolicerealization

IfwillhaverobberChenZheRutheroom,startstheautomobile,afterwrongpassword,thentheautomobilestoragebattery+12Vvoltage,theignitionelectriccurrentwayignitionlock,theignitionoutage,theengineextinguishes,againstarts,willduplicatetheaboveprocess,likethis,thebanditsandthievesalwayswillnotbeabletostarttheautomobile,willnotbeabletoachieveitsanticipatedgoal.ThealarmcircuitmainlyiscomposedbytheintegratedblockandthespeakerandelectronicswitchingSCR.Triodeorthemultiple-unittube,areforenhancetheelectriccircuitmeasurewhichthepowerbutoftenuses,ithascomposedacurrentamplificationfactorverybigequivalenttransistor,totalenlargementfactorforthesetwoenlargementfactorproduct.SCRistheelectronicswitchingwhichconstitutesbythesilicon-controlledrectifier,theelectriccapacityandtheresistanceconstitutionnegativeboosterconcurrentlyfilter,provides+3+4VtoICthevoltage,ICistracesDrawsupsoundreportstothepolicetheintegratedcircuit,thealarmapparatusbytheSCRcontrol,robsthevehiclethiefonceafterthewrongpassword,thenthestoragebatteryelectriccurrententersthesecuritysystembesidesagroup,anothergroupisstartedintheengine,afterleadstheenginework,naturalcontactoutputvoltage,afterthedifferentiatingcircuit,silicon-controlledrectifierSCRistriggered,alsopassesthroughtheresistancetofallthepressure,thevoltageaddsintheICpowersourceinputend,ICobtainsthevoltageoutputalarm,enlargesafterthemultiple-unittube,Destroysmovesthespeakertosendoutresoundinglyreportstothepolicethesound.whenstaticstate,entireelectriccircuitdoesnotconsumetheelectricity.

2.Softwaredesign

Thealarmapparatussoftwaredesignmainlydividesinto:

Masterroutine（alarmapparatusinitialization,keymodulationanddecoding）;

Alarmapparatusinterrupthandlingroutine.Thisalarmapparatusinstallsontheautomobilesteeringwheel.Afterinstalls,startsthealarmapparatus,thealarmapparatusautomaticallyretards20~30stostarttowork,inordertoletsusethepersontohavetheenoughtimetolockthega