CYPRESS PSoC for CapSense (Disti Ver)

PERFORMPSoCCapSenseTMDanielChaoFAEManager,AsiaPacific2AgendaPSoCSolution(CapSenseTM)HowItWorks-RelaxationOscillatorImplementationExamplesPSoCAdvantageAvailableDemoBoardsFAQCallToAction3CapSenseTM•PSoCCapacitiveTouchSenseSolution•Wearetrademarkingthis.•CapSenseTMistheNametouse.4AgendaPSoCSolution(CapSenseTM)HowItWorks-RelaxationOscillatorImplementationExamplesPSoCAdvantageAvailableDemoBoardsFAQCallToAction5HowItWorks:SimplePhysics•CPissumofsensorpadcapacitanceandparasitics.•CPishigherwhenfingerisonthesensorpad.•ParasiticCapacitanceisgeneratedbycouplingfromthesensorpadtotraces,groundplane,andanysurroundingconductivematerial.CPCPFinger6PSoCSolution:RelaxationOscillator30-year-oldtechnology•NoPatentRestrictionsNoexternalcomponentsrequired•NoIC•NoSummingCapacitor•NoResistorsUpto28pinsforsensingin21x34Upto48pinsforsensingin24x947HowItWorks:UsingtheRelaxationOscillator1.ChargeCpwithcurrentsource.2.Dumpatcomp.threshold.3.Countcycles(n):WhenfingerpresentCpCp+Cf,4.Measuren,5.CalculateDn.IfDnthepredefinedthreshold,6.Denotepresenceoffinger.SensorPadTimer16VDDVBGSYSCLKEnablePWM1MHziVCNnCHARGEBGPPERIODS24MHziVCNnCHARGEBGFPERIODS24D8HowItWorks:DetectingPresence1.MeasureCPbychargetime.2.ChargetimedeterminesPWMclockfrequency.3.ChangesintimercountvaluesrepresentchangesinCP.4.CompareCP.5.Denotepresenceofcapacitiveobject(finger,etc.)ifDn(DCP)isgreaterthanthreshold.FingerAbsentFingerPresent=32=48Dn=16OscillatorPWMTimer9AgendaPSoCSolution(CapSenseTM)HowItWorks-RelaxationOscillatorImplementationExamplesPSoCAdvantageAvailableDemoBoardsFAQCallToAction1003214765PSoCButtonsLEDsExample:ButtonswithPSoCCapSenseHowitworks•SetupbuttonsandLEDsattachedtoPSoC•Scanpinsinorder•Denotepresenceorabsenceoffinger•TurnonLEDforactivebutton11Example:SliderwithPSoCCapSenseHowitworks•Setupslider&attachtoPSoCpins•Scanpinsinorder•CalculateCentroid(CenterofMass)Location•Markfrequencyvalueforeachdetection•OutputpositiontohostPSoC12Example:TouchpadwithPSoCCapSenseHowitworks•SetupX/Y-matrix&attachtoPSoCpins•Scanpinsinorder•CalculateCentroid(CenterofMass)Location•Markfrequencyvalueforeachdetection•OutputpositiontohostPSoCPSoC13Example:TouchpadFingersizeisdetectedbythenumberofsensorelementsonwhichatouchisdetected.Forfingers,manyelementsareactive.Forpens,fewelementsareactive.Treatmentofpositiondataisdifferentbasedonelementnumberthresholdstatus14ImplementingIdle1)Pollsampleofpinssothatiffingerispresent,pressingmustwakeupsystem.2)Ifanypresenceisdetected,enteractivemode3)Ifnopresenceisdetected,sleepfor100msandrepeat.PSoC15SlidingSwitchesandTouch-Pads•Sliderswitchisalineararrayofindependentswitches•Touch-PadisTWOlineararraysofswitches,oneforrows,theotherforcolumns.16Diplexing(that’sdi-plexing,notdip-lexing)•Resolutiondoublingofsliderwithnoadditionalconnections•Switches0ton-1maptovirtualswitchesnto2n-1•Mappingorderselectedsothatswitchareainonehalfisscatteredintheotherhalf•Switchfindingalgorithmlooksforadjacentswitchcontacts,ignoresscatter01234567036147250123456703614725012345670361472517InterpolationMethods•Localinterpolation•Scanarray•Findlargestadjacentvalues•Computecentroid0123456703614725Peaksnotcontinuous,nopositiondetected7654321CalculatedPosition=2.8751111)1()1(iiiiiinnninininCentroid18AgendaPSoCSolution(CapSenseTM)HowItWorks-RelaxationOscillatorImplementationExamplesPSoCAdvantageAvailableDemoBoardsFAQCallToAction19ExistingSolutions21•Usehard-codedASICs•Noflexibilitytodesignchangesorcycles•LimitednumberofbuttonsperIC•RequireadditionalcontrollerICfordataprocessing•Requireexternalcomponents•Resistorsforchargecurrent,capsformeasurement•Comeonlyascompletemodules•Quickdesignchangesnotpossible•Requiredifficult-to-usecommunicationprotocols23456789120PSoCCapSenseTMImplementbuttons,sliders,trackpadsorproximitysensorsallwiththesamechip!Bringtheflexiblearchitecture,systemintegrationcapabilities,andcostreductionofPSoCtoyourcapacitivesensingapplication.21PSoCSolutionPSoCsensesallswitchesanddrivesallLEDswhilecommunicatingswitch/LEDstatustothehost.Noexternalcomponentsarerequiredforsensing.ONE-CHIPSOLUTION!!SensorPadsPSoCProgrammingandCommunicationVDD22PSoCAdvantagePSoCcanfunctionasastand-alonesolutionoraspartoralargersystem.PSoCHostPSoCM23PSoCAdvantage:ResourcesDeviceFamilyAvailableDigitalBlocksRequiredDigitalBlocksRemainingDigitalBlocksAvailableFlashMemoryRequiredFlashMemoryRemainingFlashMemory2479443116k2k14k21x344318k2k6k24PSoCAdvantagePSoCcanofferdefinitiveadvantagesfordesign…•Costreduction•BOMreduction•Flexibility/programmabilityofPSoCvs.hard-wiredASICorhard-codedROM•Multipleswitches•Upto48CapSenseinputsperPSoC!•Sensethroughupto4mmofmaterial•Easyserialcommunications•Furtherintegrationofotherboardelements•Adaptabletotouchpad(x/yorr/qmatrix)orlinearslider•Userconfigurablew/PSoCDesignertools25PSoCAdvantage:Competitors•Quantum–Fixed-functionIC•Synaptics•CirqueASIC-onlycomplete(module)solution•TouchSensorPSoCisprice-competitivewithALLcompetitorsolutions!UserhasultimateflexibilitywithconfigurabilityofPSoC!26Sleep/IdlePowerConsumptionActiveSleepIdleActiveSleepId