74ACT245-Tkool Electronics

Tkool Electronics

I.IntroductionL293DisamotorcontroldeviceproducedbyTexasInstruments.Thedevicehas4high-currenthalf-Hdrivestructures.Thisstructurecanprovideupto600mAofcurrentatavoltageof4.5Vto36V.Thisdeviceismainlyusedtodriveinductiveloads,suchasrelays,solenoids,DCorbipolarsteppermotors.CatalogI.IntroductionII.L293DFeaturesIII.L293DPinoutConfigurationIV.CircuitDesign4.1IntroductiontoMobileNurseRobot4.2PeripheralCircuitDesignofMotorDriveDevice4.3NurseRobotCircuitDesign4.4MicrocontrollerandItsPeripheralCircuitDesign4.5TheDesignofPowerSupplyanditsDeviceSelection4.6HardwareConnectionDiagramandSoftwareDesignV.ConclusionFAQOrdering&QuantityII.L293DFeaturesWideSupply-VoltageRange:4.5Vto36VSeparateInput-LogicSupplyInternalESDProtectionHigh-Noise-ImmunityInputsOutputCurrent1APerChannel(600mAforL293D)PeakOutputCurrent2APerChannel(1.2AforL293D)OutputClampDiodesforInductiveTransientSuppression(L293D)III.L293DPinoutConfigurationThepinarrangementofL293DisshowninFigure1.Pins1A,2A,3A,and4Aarecontrolsignalinputterminals,whichareusedtocontroltheworkingstateofthemotor.Thepins1Y,2Y,3Y,and4Yaremotorcontroloutputterminals,whichareusedtodirectlycontroltheactionsofthemotor.Figure1L293DpinoutAllinputsofthedeviceareTTLcompatible,anditsoutputadoptsatotempoledrivecircuitcomposedofaDarlingtontransistorreceiverandapseudoDarlingtonsource.Themotordriveenableiscontrolledbypins1and2ENtocontrolmotor1,andpins3and4ENtocontrolmotor2.WhentheENpinissettohighlevel,themotorcorrespondingtoitisintheenabledstate,therebyactivatingthemotorcontroloutput.TheVCC1portisolatedfromtheVCC2portcanprovidelogicinputstoreducepowerconsumption.L293Dcanworkintherangeof0℃～70℃.IV.CircuitDesign4.1IntroductiontoMobileNurseRobotThemainpurposeofthemobilenurserobotistotreatpatientswithmedicalstaff,trytoavoidcontactwithgerms,reducegerminfection,reducemedicalstaffsconcerns,andreplacemedicalstafftodosomesimpletasks.Inotherindustries,therobotcanalsodosimpletasksforpeople,savelabor,andimprovesocialworkefficiency.Themobilenurserobotisvoice-controlled,andcanautomaticallynavigateaccordingtothevirtualtrack,andautomaticallydetectmetalduringthenavigationprocess,sothattherobotcanstopatapredeterminedpositionandpromptthepatientthattheitemsneededhavebeendelivered.Therefore,themobilenurserobothasthefollowingcharacteristics:Voicecontrolfunction.Themaincontroldeviceoftherobotisintegratedwithavoicerecognitionmodule,whichreceivesvoicecontrolfromaspecificperson,andtherobotperformsdifferentoperationsaccordingtodifferentcommands;Virtualtracknavigationfunction.Therobotreadsthedataaccordingtotheinfraredsensorinstalledonthemainbody,judgeswhetheritdeviatesfromthepredeterminedtrack,andcorrectsittorealizethefunctionofvirtualtracknavigation;Fixed-pointpositioningfunction.Thetailoftherobotdetectsmetalaccordingtothemetalsensor,andperformscorrespondingstopandforwardoperations,soastoachievethefunctionofpositioningtherobotatapredeterminedpoint;Voiceplaybackfunction.Thepre-inputvoiceisplayedoutatthefixedpointtoplaythevoicepromptfunction.4.2PeripheralCircuitDesignofMotorDriveDeviceTheexternalcircuitmustbeconnectedtoahigh-speedoutputclampdiodefortransientsuppression,asshowninFigure2,justusetheordinaryIN4001.Whentheinputenableislow,themotorcontroloutputofthedeviceisshielded.Atthistime,themotorcontroloutputofthedeviceisclosedandinahighimpedancestate.Whenthecontrolsignalisinputtotheinputterminalofthedevice,allHreversibledrivecontrolsolenoidormotorapplicationcircuit.Figure2LEDexternalcircuitdiagram4.3NurseRobotCircuitDesignThemaincontrolcircuitboardofthenursemobilerobotperformsthefollowingfunctions:ItcandirectlydrivetheDCmotorofthemobilenurserobottocontrolitsactions;ItcanprovidecorrespondingpowertotheDCmotor,sensor,single-chipandswitchontherobot;Itcanreceiveremotecontrolsignals.4.4MicrocontrollerandItsPeripheralCircuitDesignWhenselectingthesingle-chipmicrocomputer,therelevantmaterialsoftheobstacleavoidancemobilerobotwereconsulted.Takingintoaccountthedesignrequirementsofthenursemobilerobot,thecost-effectiveandpowerfulSunplusMicrocontrollerSPCE061Awasadopted.Theperipheralcircuitofthesingle-chipmicrocomputerinthisdesignmainlyreferstotheSPCE061Asimplifiedboardcircuit.4.5TheDesignofPowerSupplyandItsDeviceSelectionTheintegrationofthepowersupplypartmainlyusesthethree-terminalintegratedvoltagestabilizer7805.Theoutputofthe78seriesispositivevoltage,andtheoutputpowerisdifferentaccordingtothedifferentmodels.Theoutputcurrentof78Lseriescanreach0.1A;theoutputcurrentof78Mseriescanreach0.5A.Takingintoaccounttheactualpowerconsumptionofthemicrocontroller,a78M05isselectedtoconvertthe12VDCvoltageintoa5VDCvoltage.SunplussSPY0029canefficientlyconvertDC5VtoDC3.3V.Aftertesting,itisfoundthattheoutputDCrippleissmall,whichcanreliablyensuretheCPUs3.3Vpowersupply.Whentheinputvoltagefluctuatesto7V,thehigh-quality3.3VDCoutputcanstillbeguaranteed.TheintegratedpowersupplycanprovidethemaincontrolcircuitboardwithDC12V,DC5VandDC3.3Vthreepowersources,respectively,tosupplypowertotheDCmotor,sensor,andCPUofthemaincontrolboardtomeetthedesignrequirements.4.6HardwareConnectionDiagramandSoftwareDesignUseSPCE061Atocontroltherobot,useIOB3~IOB6andIOA0~IOA11ports,aswellasspeakerinfraredsensor,metalsensor,triggerswitch,remotecontrolmodule,etc.Figure3showsthecircuitconnectionofthemaincontrolboardofthenursemobilerobot.Figure4showsthedesignflowchartofthemaincontrolsoftwareofthenursemobilerobot.Themaincontrolboardismainlyusedtoreceivecontrolsignals(thenursemobilerobotsensitivelyreceivesthecontrolsignalssentbythepart)andperformcorrespondingoperations.Theactionsofforward,turnleft,andturnrightarerelativelysimpleandwillnotbedescribedindetailhere.Figure3BlockdiagramofmaincontrolboardcircuitconnectionFigure4FlowchartofthesoftwaredesignofthemaincontrolboardoftherobotThevirtualtracknavigationpartinvolvesthereadingandjudgmentofsensorsignalsandthecompletionofthenavigationprocess,whicharethecoreofthisdesign.ThefollowingistheinterfaceprogramcodeoftheMCUtocontrolthemotorthroughtheL293D:V.ConclusionThemobilenurserobotcombinesmechanicaltechnology,electroniccircuitdesignandsoftwaredesign,andexpandspartofthedrivecircuitoftheDCmotoronthebasisofthesingle-chipSPCE061A.Inpracticalapplications,thecombinationofL293Dandsingle-chipmicrocomputerhasgoodcontroleffectandhighsensitivityonDCmotors,andcancompletevirtualtracknavigation