mTouch电容触摸屏解决方案

Capacitivetouchtechnologies©2008MicrochipTechnologyIncorporated.AllRightsReserved.ClassTitleSlide1mTouch™CapacitiveTouchSolutions©2008MicrochipTechnologyIncorporated.AllRightsReserved.ClassTitleSlide2WhatismTouch™CapacitiveTouchSensing?Alternativetotraditionalpush-buttonRequiresnomechanicalmovementEnablesacompletelysealedandmodern-lookingdesignLowercostUsedinanyapplicationwithaUserInterfaceApplianceConsumerIndustrialMedicalAutomotiveCouldbeKeysorSlider©2008MicrochipTechnologyIncorporated.AllRightsReserved.ClassTitleSlide3IntroductionoffingerproducesaparallelcapacitanceCsCPEquivalentCircuitSoweneedtomeasureacapacitanceanddetectashiftinitsvalueHowdoesCapTouchwork?CPFSensorCapacitance(CS)=CP+CFIroninBloodCF©2008MicrochipTechnologyIncorporated.AllRightsReserved.ClassTitleSlide4CapacitivemTouch™SolutionsSensingComparatorComparatorwithSRLatchIntegratedCapacitiveSensingModuleNEWChargeTimeMeasurementUnitModule©2008MicrochipTechnologyIncorporated.AllRightsReserved.ClassTitleSlide5MCUPERFORMANCEAVAILABLECHANNELSNEW14Upto16MethodsforCapacitiveTouchSensing©2008MicrochipTechnologyIncorporated.AllRightsReserved.ClassTitleSlide6mTouch™isusingtwomethodsRelaxationoscillatorMeasuresFrequencybasedonacapacitancevalueNeedsComparator,SRLatchmoduleornewCapacitiveSensingModuleChargeVoltageDirectMeasurementChargesacapacitancewithafixedcurrentforafixedtime.ThenmeasurethevoltagewiththeA/DUsedbyCTMU(ChargeTimeMeasurementUnit)NewAppNoteusingPIC10F©2008MicrochipTechnologyIncorporated.AllRightsReserved.ClassTitleSlide7Canbeusedas:OneKey:On/OffbuttonProximitysensor:DetectingthehandcomingclosetothekeypadLowerstandbypowerconsumptionMarketingWowfactorCandriveLEDorBuzzerUsingPIC10F204/6SWprovidedAN1202Itistheonly6pinsMicro-basedsolutionMicrocontrollerswithS/RLatchmoduleComparatorwithmuxandS/RlatchPIC16F610/616,PIC16HV610/616PIC16F690familyPIC16F88XfamilyPIC18F14K50Firmware:Approximately250Instructions30-40BytesRAMNEW©2008MicrochipTechnologyIncorporated.AllRightsReserved.ClassTitleSlide8NewCapacitiveSensingModuleforPIC16F©2008MicrochipTechnologyIncorporated.AllRightsReserved.ClassTitleSlide9UsetheRelaxationOscillatorMethodComparetotheSRLatchModule:MoreHardwareIntegrationNoexternalcomponentrequiredSave3I/OsMoreInputs8Channelson28pins=upto16Keys(4x4Matrix)16Channelson44pins=upto64Keys(8x8Matrix)CanoperateinSleepModetosavepowerWDTasTimeBaseThefirstfamilyisthePIC16F72XChargeTimemeasurementUnitCTMU©2008MicrochipTechnologyIncorporated.AllRightsReserved.ClassTitleSlide10ConsistsofcurrentsourceandcontrollogicWorksinconjunctionwiththeA/DCanbeusedtoMeasuretime,capacitanceorchangeincapacitanceFixedcurrentsourcechargetheCapacitanceforafixedtimeAllowsforfasterbuttonresponsetimecomparetotheRelaxationOscillatorProvidesupto16channels64KeysMatrixThefirstfamilyisthePIC24FGA1/GB1Whentousewhat?©2008MicrochipTechnologyIncorporated.AllRightsReserved.ClassTitleSlide11Thankstoourlargeoffer,thechoicewillbemainlydictatedbytheapplicationneeds:I/Os,MemoryCommunicationDisplayCPUperformancerequiredUSB,Ethernet…..Forexample:Sowhatisthecostperkey?Wecan’tanswerbecauseitdependson:CustomervolumeApplicationneeds:Lowendwithalotofkeys/HighEndwithonlyacoupleofkeysSoworkwiththecustomertofullyunderstandtheapplicationfirstOneKeyorProximitysensorGoCheapandEasywithPIC10FSmall4keyskeyboardTheS/Rlatchmoduleisthemostcosteffectivesolutiononthemarkettoday15keyswithCommunicationPIC16F72XisthewaytogoUIwithDisplay,USB,SpeechHelloPIC24FGB1WhatAreSomeOfTheCapacitiveTouchTechnologyChallenges?©2008MicrochipTechnologyIncorporated.AllRightsReserved.ClassTitleSlide12Detectinga5%-20%shiftinpico-FaradsHeat,Humidity,adjacentmetal,andenvironmentalshiftPeoplesometimesweargloves,touchwithnails,etc.SoindependentlyoftheHWusedtodetectacapacitanceshift,determiningatouchisprimarilyasoftwarechallengemTouch™CapacitiveTouchAlgorithm©2008MicrochipTechnologyIncorporated.AllRightsReserved.ClassTitleSlide13FirmwareAlgorithmThealgorithmisindependentoftheHW(SRLatch,CSMorCTMU)ComparelatestmeasuredvaluewithslowmovingaverageAutomaticallyadjustforenvironmentalchangesTriplevelisrelativetomovingaverageSensitivityremainsconstantOtherfunctionsimplementedthesameasnormalbuttons:DebouncingTouchandreleaseEtc.TimeFrequencyAbsoluteAverageSensorTouched©2008MicrochipTechnologyIncorporated.AllRightsReserved.ClassTitleSlide14SensorReleased‘Floating’TriplevelImplementation*ComingsoonFW:Turn-keysolutionbutwithsomelimitationsLibrary:EasytointegrateCapTouchinanapplicationSourceCode:DesignerhasfullcontrolMicrochiphasthemostflexibleoffer©2008MicrochipTechnologyIncorporated.AllRightsReserved.ClassTitleSlide15FWLibrarySourceCodeCompetitor1YesN/AN/ACompetitor2YesYesN/AMCHPYes*YesYesAvailableResources©2008MicrochipTechnologyIncorporated.AllRightsReserved.ClassTitleSlide16mTouch™designcenter: