TheAuto-ReturningRemoteControlBoatGroup#47

SomakGhosh

ZainZaman

GrantEverett

TA:VigneshSridhar

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TableofContents

1Introduction1.1Objective1.2Background1.3HighLevelRequirementsList

22223

2Design2.1BlockDiagram2.2HighLevelFunctionOverview2.3PowerUnit2.3.1Batteries2.3.2LowVoltageDetectorCircuit2.3.3VoltageRegulator2.4ControlUnit2.4.1.Microcontroller2.4.2PowerControlLogic2.5SignalUnit2.5.1Overview2.5.2RelativeSignalStrengthIndicatorCircuit2.5.3SchmittTrigger2.5.4Sensor2.5.5AntennaArray

334446

10111115181819232526

3ToleranceAnalysis 264Cost 275Schedule 286EthicsandSafety 297References 318Appendix 33

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1Introduction

1.1 ObjectiveProfessorOelzepresentedwhatseemedtobeaverystraightforwardproblemwithamodelboatofhistotheECE445class.Hesailsthisremotecontrolboatonalakeandwhilethefunctionalityworkswell,whentheboatrunsoutofbatteryorthesignalfromtheremotecontrolbecomestooweak,hemustphysicallyretrievetheboatfromthelake.Inordertotackletheproblemathandwewillhavetocreateseveraldifferentmoduleswhichwillworktoensurethattheboatwillreturntoitsdesignatedhomelocation.Wewillhavetocreateabatterymanagementsystem.Thiswillbedonebymakingalowvoltagedetectorcircuitwhichwillactwhenthebatterysupplyislowandwillbeusedtoguidetheboatbacktoshore.Thenextkeymodulewillbethesignalstrengthdetector.Thiscomponentwilldetectwhentheboatisinalowsignalrangeandclosetohavingnosignal.Thegoalofthismodulewillbetostoptheboatandreturnalocationwithstrongersignalandwithinasaferange.Itwillbeguidedbyanantennaarrayandasignaldetectioncircuit.Wealsoplantoimplementcontroltotheboat.Thiscontrollerwilltakesignalfromvarioussensorsontheboatanditwillsteertheboatandpowerthemotor.Allofthesecomponentswillbecomplementedandcontrolledamicrocontroller.Thisisahighleveldescriptionofthesolution.Eachtechnicalcomponentwillbediscussedinmuchfurtherdetailbelow.

1.2 BackgroundThisprojectwasmotivatedfromareal-worldissueandcanbeappliedtoallchildren’sproducts.Manyoftheremotecontrolproductsarevery“low-tech”andhaveverylittlefail-safeoptionsforusewhentheconditionsarenotideal.Whentheyareusedbychildrentheyaredestroyedafterveryfewuses.Thisdoesverylittletojustifythecostsoftheseproducts.However,webelievethatwithsomeupgradesthesetypesofproductscannotonlylastmuchlonger,butalsobemuchmoreenjoyablewhenused.

Thistechnologyhasseveralotherpotentialapplications.Itcouldbeaveryusefuladditiontodronetechnologyduringwartimeandfordeliveringsuppliessafelyandreliably.Withtheincreasedreliabilityandrobustnessthatourdesignwouldhavedronescouldbeusedinmorelocationswithlesspowerandmorereliability.Inareaswhererechargesandlargebatterypacksarenotaccessiblethistechnologycouldhavemanyapplications.

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1.3 HighLevelRequirementsList1. Requirement1isthattheboatmustbeabletodetectwhenithasbelowtherequiredbattery

level(subjecttofurthertesting,approximately4.8V)andhaveenoughreservestoreturnhome.

2. Requirement2isthattheboatmustbeabletodetectwhentheReceivedSignalStrengthIndicator(RSSI)isbelowadequatelevelsandbeabletoreachastrongersignalpointorreturnhome.

3. Requirement3isthatboatwillconsistentlyreceivecorrectsignalsfortheangleanddirectionaswellguideitselfbackintoaregionofsafetywithintherequiredRSSI.

2 Design

2.1BlockDiagram

Figure2.1:Highlevelblockdiagram

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2.2 High-LevelFunctionalOverview&PhysicalDesignTheblockdiagramdesignconsistsoffourprimaryunits:TheHandheldRemoteControl,theSignalUnit,theControlUnit,andthePowerUnit.TheHandheldRemoteControlcommunicatesdirectlywiththeSignalUnitviaIRsignalstodeterminethelocation,route,andthe‘homedestination’.TheSignalUnitconsistsofanRSSI(RelativeSignalStrengthIndicator)modulewhichmeasurestherelativesignalstrengthfromtheuser.TheControlUnit,whichcontrolsthemotorandrudder,usesdatareceivedfromthePowerSystemandtheSignalunittoevaluateiftheboatneedstoreturnhomeortoaregionwithintheRSSIrequirements.Inadditiontopoweringtheboat,thepowersystemincludesacircuitthatdetectswhenthebatterylevelisonlyhighenoughtomanageaone-waytripbackhome.(HomeisdefinedasalocationwheretheRSSIsignalstrengthisthemaximum).

Forourphysicaldesigntheintegrityandshapeoftheboatwillbekeptintact.Theboatwaspreviouslysealedwhichweopenedtoaddallofourelectricalcomponentsinordertointegratewiththeexistinghardware.Tomitigateallsafetyconcernswecanuseasimilargradeepoxytosealtheboat.Thephysicalshapewouldbeleftintactwithsomeaddedweightandallsafetyconcernswouldbesolvedbyusingtheepoxytowaterprooftheboat.Theperformanceoftheboatshouldnotbeaffectedfromtheadditionswearemakingandfromtheoutsidetheboatshouldlookexactlythesame.

2.3 PowerUnit

2.3.1BatteriesParts:(6x)DuracellAAAlkalineBatteries1.5VMN1500(LR6)

Theboatispoweredby6AA,1.5Vbatteriesaddinguptoproduceatotalof9V.Typically,mostAAbatteriessharesimilarcharacteristics.Inthisthisproject,theDuracellMN1500wasused.Table3.1belowstatestheproductspecificationswhileFigure3.1representsthetypicalchargecharacteristics.

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Table3.1:Batteryspecifications[1]NominalVoltage 1.5VOperatingVoltage 1.6-0.75V

Impedance 120m-ohmat1kHzTypicalWeight 24gm(0.8oz.)TypicalVolume 8.4cm3(0.5in.3)

Terminals FlatStorageTemperatureRange -20°to35°(Celsius)OperatingTemperatureRange -20°to54°(Celsius)

-4°to130°(Fahrenheit)ANSI 15AIEC LR6

Figure3.1:Batterydischargecurveat21°C(70°F)[1]

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2.3.2LowVoltageDetectorCircuit

Parts:MMSZ4681T1GZenerDiode,(3x)1MWResistor,100kWResistor,TexasInstrumentsTL331

Thelowvoltagedetectorcircuitwillmonitorinputfromthebatteriesandcommunicatewiththecontrolunittoindicatewhenthereisonlyenoughpowerleftfortheboattoreturntothehomelocation.AccordingtoTable3.1,theoperatingvoltageforthebatteryinusehasalowerlimitof0.75V.Sincewehavesixofthosebatteries,thelowestvoltagelevelbeforethebatteriesareineffectiveis4.5V.Asaresult,thevoltagelevelatwhichthecircuitsignalsthecontrolunittoforcetheboatbackhomeshouldbeatavaluegreaterthan4.5V.Henceforth,thisvoltagewillbereferredtoastheindicationvoltage.

Totestfortheindicationvoltage,wewillfirstmeasurethevoltageofthebattery.Next,wewillphysicallysettheboatonabodyofwaterandhaveitcompletearound-tripfromtheusertoitsmaximumrange.Upontheboat’sreturn,thevoltageofthebatterieswillbere-measured.Sincethebatterylevelconsumedwouldrepresenttwofull-rangetripsoftheboat,thetotalbatterylevelconsumedwillbedividedby2.Thetestwillbeperformedthriceandtheaveragevalueswillbetakentoensureaccuracy.Finally,theresultantvoltageconsumedwouldbeaddedtotheminimumoperatingvoltageof4.5Vtoobtaintheindicationvoltage.

Althoughnophysicaltestshavebeenperformed,acutoffvalueof4.8Vfortheindicationvoltageshouldbefeasibletheoretically.Thisisbasedofftheassumptionthata6.67%chargeshouldbeallthatisrequiredforaone-waytripbacktothehomelocation.However,sincethisassumptionisnotbackedbyfactualinformation,arangeofvaluesrelatingthebatterylevelandindicationvoltageisshownintable3.2.

𝑉#$%#&'(#)$ = 4.5𝑥100 + 4.5

𝑥:percentageofbatterylevelrequired

Table3.2:BatterylevelrequiredvsindicationvoltageBatteryLevelRequired(%)

IndicationVoltage(V)

5 4.7257 4.81510 4.9512 5.0415 5.175

Figure3.2showsaschematicofthelowvoltagedetectorcircuitgeneratedonEagle.ThecircuitusesasingledifferentialcomparatorintegratedintheTexasInstrumentTL331chip[2].Thechiptakesintwoinputsanddependingonwhichoneofthevaluesishigher,outputsadigital

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HIGHorLOW.ItisoriginallyconfiguredtooutputaHIGHwhenVin+isgreaterthanVin

-,andalowwhenotherwise.Ourprojectdemandsthatthelowvoltagedetectorcircuit,outputsahighwhenevertheindicationvoltageisreached.Therefore,thecircuitusedisaninvertingcomparatorcircuitwherethebatteryisconnectedtothenegativeterminal,Vin

-whichistobeusedasthereferencevoltage.Thepositiveterminal,Vin

+receivesthevoltageacrosstheZenerdiodeastheinput.TheZenerdiodeisusedtoregulatethevoltage.Therefore,evenwitha9Vinput,a2.4VZenerwouldhaveavoltageofapproximately2.4V+/-5%goingintoVin

+.WeconnecttheVCCpinsuchthatittakesinthevoltagedirectlyfromthebattery.Asthevoltagekeepsreducing,theinputvaluesofVin

+andVin-convergeuntilVin

+exceedsVin-whichmeansthat

theindicationvoltagehasbeenreached.Thisaccordingtooursimulationresults,tendstohappenaroundtheloweredgeZenervoltageofthediodeused.

Figure3.2:Eagleschematicofthelowvoltagedetectioncircuit

Table3.3:ZenerDiodespecifications[3]Circuit

SchematicSymbol

Device Marking ZenerVoltage LeakageCurrent

VZ(Volts) @IZT IR@VRMin Nom Max µA µA Volts

D2 MMSZ4681T1G CF 2.28 2.4 2.52 50 2 1D1 MMSZ4684T1G CK 3.13 3.3 3.47 50 7.5 1.5

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ResistancefordiodesD1andD2:(Equation1)

𝑅FG =𝑉H#$𝐼FJ

=4.5

50×10LM = 90kW

MaxinputcurrentintoD1andD2:(Equation2)

𝐼F =𝑉H'P𝑅FG

=9

100×10LQ = 90µA

Usingequations1and2andrelatingthesolveddatatotheZenerdiodespecifications[3],resultedinthe100kWbeingchosentobeconnectedtothediodesD1andD2.

Table3.3representsthespecificationsoftheZenerdiodesused.ThecircuitusesavoltagedividerattheVin

-terminaltodividetheincomingbatteryvoltageby2.ThismeansthatthemaximuminputvoltagefedintoVin

-is4.5V.Vin+,ontheotherhand,staysataconstant2.4V

(+/-5%)duetothevoltageregulationcharacteristicofD2.Testresultsofthecircuitsimulationareshownintable3.4andfigure3.3.

Table3.4:LowVoltageDetectorCircuitSimulationOutput

BatteryVoltage(V)

Vin-(V) Vin

+(V) Output

9 4.5 2.4 LOW8 4 2.4 LOW7 3.5 2.4 LOW6 3 2.4 LOW5 2.5 2.4 LOW4.8 2.4 2.4 HIGH4.75 2.375 2.4 HIGH

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Figure3.3LowVoltageDetectorCircuitSimulationOutput

Basedontable3.4,itcanbeseenthatassoonastheindicationvoltageisreached,thecomparatoroutputsalogicHIGHtothecontrolunittoindicatethatthebatterylevelislow.Thecontrolunitthenproceedstodeterminetheboat’snecessarycourseofaction.TheLOWcorrespondstoavoltageof0,whiletheHIGHwillbeequaltothebatteryvoltageascanbeseeninfigure3.2.Figure3.3usesaconsistentoutputvoltageof3.3Vtomakethegrapheasiertointerpretandunderstand.Inreallifeexperimentation,thevoltagewillrangefrom4.5to9V.Sincetheinputthatthecontrolunitreceivesisadigitallogicinput,thevalueofthevoltageitselfwillnotmatter(allvoltagesrangingfrom4.5Vto9VwillresultinthesameoutputofaHIGH);unlessitis0orveryclosewhichwillcorrespondtoaLOW.

Thesimulationresultsareperfectsincetheydonotaccountforthenon-idealityofthedevicesused.Therefore,anexactvaluedecimalvalueof2.4VshouldnotbeexpectedfromtheZenerneithershoulditbeassumedthatthebatterysuppliesexactvaluessuchas9.0oran8.0.Moreover,itisalsoimportanttomentionthattheresistanceswouldhaveanin-builtpercenterrorofaround+/-5%.However,theseirregularitiesanderrorswillbeabletobedealtwithbestonlyduringthebuildprocess.

Table3.2indicatesarangeof4.725to5.175Vfortheindicationvoltage.Thecircuititself,canbeconfiguredtomatchthevalueobtainedexperimentally.ThiswillbedonebychoosingdifferentvaluesfortheZenerdiodes,D1andD2.

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Requirements Verifications

1. TheTL331shouldoutputalogicalHIGHinsteadofLOWwhenthebatteryvoltagedropsbeloworequals4.8V(+/-5%)

1. Useadcpowersupplytopowerthecircuitandthenusetheoscilloscopetodetectif:

A. aHIGHoutputisgeneratedwhenthevoltageacrossR1,1MWislessthanorequalto4.8V(+/-5%)(figure3.2)

2.3.3VoltageRegulatorParts:STMicroelectronicsL4931,2.2uFCapacitor(x2)

ThevoltageregulatorwillbeusedtosupplyaconstantvoltagetothecontrolunitandtheRSSI(RelativeSignalStrengthIndicator)circuitthatadherestotheirinputrequirement.Inthiscasetheinputvoltagerequiredwas3.3V,thereforetheSTMicroelectronicsL4931waschosen.TheL4931isalinearvoltageregulatoroutputs3.3Vforanyvalueinourbattery’soperatingrange(4.5V-9V)[6].Figure3.4displaysthecircuitschematic.

Figure3.4:L4931CircuitSchematic[6]

Requirement Verification1. Outputavoltageof3.3V(+/-5%)intoVCC

whenthebatteryvoltageisgreaterthan4V(+/-5%)

1. Useamulti-metertomeasurethevoltageacrossD1andverifythatitis3.3V(+/-5%)wheneverthebatteryvoltageisgreater4V

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2.4 ControlUnit

2.4.1MicrocontrollerPart:ATmega328P

Themicrocontrolleristheprimarycomponentofthecontrolunit.ThemicrocontrollerwilltakeinputsfromtheRFreceiversandsensor.Thiswillbean8-bitmicrocontrollertoproperlyexecutethecomputationrequiredforourBang-BangControlLoop.Whilethiscouldbedoneona4-bitmicrocontroller,thesensorweusehasan8-bitresolution[7].

ThemicrocontrollerwilltakeaninterruptfromthePowerControlLogic.Whenthisinterruptistriggered,wewilldisablesleepmode.Wewillalsocheckthevalueofthiswheneverwecompleteanentirecontrollooptoseeifweneedtoreactivatesleepmode.Wereactivesleepmodewhenwewanttoallowtheusertocontroltheboat.Figure4.1isablockdiagramshowingtheinputsandoutputstothemicrocontroller.Itwilltakeananaloginputfromtheantennaarray,andadigitalinputfromthemagnetometer.Finally,itwilloutputaPulseWidthModulator(PWM)totheESC(ElectronicSpeedControl).

Figure4.1:Microcontrollerinputandoutputhardwarecomponents

Ourcodewillbeoptimizedbasedonwhetherornotwehavereaddatafromthemagnetometer,sincethatisthebottleneckintermsoffrequency.Thetwopossiblestates,SerialandJump,arechangedduringtheReadDataandChangeStates.ThisisdonetooptimizeournumberofInstructionsPerSecond.TheReadRFsensorandSave,CalculateDesiredDirection,CalculateOurDirectionblockswillalloperatewithawrapper.Uponcompletionofthisblock,thiswrapperwilldecideifweexecutethenextblockorifwePollMagnetometeragain.IfweareintheSerialExecutionstate,wewillsimplyexecutethenextcalculation.IfweareinJumpExecutionstate,thewrapperwillsaveavaluecorrespondingtothenextrequired

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block,thenPolltheMagnetometer.WhenwegettotheJumptoNextNon-ExecutedBlock,wewilljumptothefunctionassociatedwiththesavedvalue.Theflowchartforthecodeisdepictedinfigure4.2.

Figure4.2:Flowchartforthemicrocontrollercode

RequiredNextmeansthatwecontinuetothatinstructionregardlessofstate.Forconditionalblocks,wealsorequiretheBooleanoutputtobeequivalent.SerialExecutionmeansthatwefollowthegreentransitions,providedweareintheSerialExecutionstate.JumpExecutionmeansthatwefollowthebluetransitions,providedweareintheJumpExecutionstate.Thesestatesarepartofthesoftware.

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WehavechosentheATmega328Pasthemicrocontrollerforthisprojectforavarietyofreasons.Mainlybecauseitisalowcost[5],readilyavailable8-bitmicrocontroller.Italsosatisfiesalltherequirementsofhavinginterruptpins,PWMoutputandsupportsoperationat3.3V[4].Additionally,thecurrentat1MHzfrequencyand3.3Vis0.92mA,whichyieldslowpowerconsumption[8].Atthisspeed,wecanperform12,500instructionsbeforethemagnetometerhasdatareadytoread.Thecalculationbelowverifiestheclaim.

1000000𝐼𝑃𝑆80𝐻𝑍 = 12500𝐼𝑛𝑠𝑡𝑟𝑢𝑐𝑡𝑖𝑜𝑛𝑠

IPS=InstructionsPerSecondorInstructiontimesHertz

Requirements Verification1. DesiredSleepModefunctionsas

expected:a. ExitsleepmodewhenPCLis

logicalHIGH2. EntersleepmodewhenPCLislogical

LOW

1. SimulateaPCLHIGHvaluewhenmicrocontrollerisinsleepmode,ensuremicrocontrollerwakesup

2. SimulateaPCLLOWvaluewhenmicrocontrollerisinsleepmode,ensuremicrocontrollerdoesnotwakeup

3. SimulateaPCLLOWvaluewhenthemicrocontrollerisnotinsleepmode,ensurethemicrocontrollerenterssleepmodeafterthecurrentcontrolloophasfinished

2. DrivePWMsuchthatthefrequencyandamplituderepresenttheanglechangeweneedtomake

2. Givenoutputs(phase,speed)fromtheBang-Bangcontroller,ensurethePWMhasthecorrectdutycycle,frequencyandamplitudeasdescribedinthePWMRequirementsandVerifications.Theseoutputswillbeanangle,andthisangleisthedifferenceindirectionweneedtotake.

WewillimplementaBang-BangController,PulseWidthModulator,andconnecttoanElectronicSpeedControlleronthemicrocontroller.

Controller

Forthecontroller,wewillbeusingBang-BangControl.Thistypeofcontrollerisusedbecausewehaveabinaryinputwhichwillonlyneedtohave2-fixedpositionstoswitchbetween.The

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motorwilleitherbeonoroffandwillsteerinadirectionbaseduponthesignalreceivedfromthePulse-WidthModulator.

Requirements Verifications1. Theboathas2behaviors-

A. themotorisonwhentheboathasbothsufficientpowerandsignal

B. whenboathaseitherlowbatteryorlowsignalthemotorwillshutoffandwaitforinstructionsforcorrectdirectiontotravelin.

1. Testthebehaviorofthecontrolsystem(simulatedusingSimulinkonMATLAB)onamotorforrequirements

2. Inputa0formotorspeedandensurethatthemotorisnotrunning.

3. Inputaspeedgreaterthan0tothemotorandensurethatthemotorisrunning.

2. Theboat’sElectronicSpeedControlcansuccessfullyreceivecorrectpulseinformation-

A. thepulseamplitudewillencodethespeedwithin(+/-5%error)

B. thepulsephasewillencodetheanglewithin(+/-5%)

2. TestthebehaviorofthecontrolsystemusingSimulinkandthemicrocontroller.InputadesiredangleandspeedtothemicrocontrollerandverifyifthePulseWidthModulatorissendingthecorrectdirectiontotheelectronicspeedcontrolandthemotor.Thisbehaviorcanbesimulatedandthedatawillbereturnedinthesamescript.

PulseWidthModulator(PWM)

Part:WewilluseaPWMimplementedonthemicrocontrolleritself.

ThepurposeofthePWMwillbetosendinformationtotheelectronicspeedcontroller.ThePWMwillsendamessagesignaltotheelectronicspeedcontrollercontaininginformationonthedesiredpoweroutputtothemotorandthenecessarydirectionoftraveltore-enterastrongersignalrangeorreturntoshorebecauseoflowbattery.Theencodedmessagewillcontinueboththespeedandanglethattheboatwillneedtotravelin.Thespeedistheamplitudeofthepulseandtheangleisthephaseofthepulse.ThePWMwillsendasignalevery2-3millisecondsandwilloperateatafrequencytomatchtheElectronicSpeedControl(ESC).WewillpurchaseaPWMcompatiblewiththeESCwehavechosen.

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Requirement Verification1. ThePWMshouldworkat1kHzto

matchtheelectronicspeedcontrol1. Usevariousdutycyclesandonthe

frequencyandsimulatewhetherthePWMisstayinghighforaslongasneededbytheelectronicspeedcontrolandalsocompletingcyclesasfastasitshould.

2.4.2PowerControlLogicPart:SN74LVC2G32Dual2-InputPositive-ORGate

PowerControlLogic(PCL)outputsadigitalsignaltoaninterruptpinonthemicrocontroller.ThePowerControlLogicimplementsthestatemachineusing3states.ThefinitestatemachinediagramforthePCLisshowninfigure4.3below.

Figure4.3:FiniteStateMachineDiagram

ThestartstateinthisfinitestatemachineistheSstate.Fromtherewechangestatesdependingontwoothercomponents.SSDandLVD,whichrefertotheSignalStrengthDetectorandLowVoltageDetectorrespectively.Anacceptedstateinthisstatemachinemeansthatthemicrocontrollerwillbepowered.Lastly,theXisadon’tcare;meaningthatwewillalwaysstayinthatstateevenifSSDHigh,SSDLoworLVDLowistriggered.

StartinginstateSmeansthattheuserisincompletecontroloftheboat.FromS,wehavetwopossiblepaths,eitherSSDHighorLVDHigh.TheSSDHighoccurswhentheSSDhasalogicalHighoutput.Thistransitionbringsustotheacceptedstate-SSD.Thisstate’spurposeistokeep

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themicrocontrollerONuntiltheboatisbackinsignalrangeofthehandheldcontroller.ItfollowsthatSSDLowwouldbringustoS.Thisisbecauseoncewearebackintosignalrangewewanttheusertocontinueenjoyingtheboat.

FromSSDwecanalsotransitionwithLVDHigh.ThistransitiontakesustotheacceptedstateLVD.TheotherpathtothisstateisfromSandreceivingLVDHighasaninput.LVDHighmeansthattheLVDhastriggeredandwearelowonbattery.OnceweareinLVD,wewillneverleavethisstate.ThisisbecausewhentheLVDhastriggered,thereisclosetonopowerleft.Thus,theuserwillnotbeabletousetheboatuntilithasreachedhome.

ThePowerControlLogicwillbeimplementedusinglogicgatesduetotheirlowcostandlowenergyusage.ThePCLwilltaketheoutputfromtheLowVoltageDetectorandstoreitusingasimpleORgate.TheORgatesusedwillbea2-bitORgate,withoneinputbeingtheoutputfromtheLowVoltageDetectorandonebitbeingtheoutputfromtheORgate(figure4.4).ThisisthemostefficientwayofstayinginstateLVD.TherewillbeasecondORgatewhichtakesinputfromthepreviousORgateaswellastheSignalStrengthDetector.

Figure4.4:ControlLogicforLVD&SSDcomponents

Table4.1:TruthTableforPCL

PowerControlLogic SignalStrengthDetectorLOW HIGH

LowVoltageDetector LOW LOW HIGHHIGH HIGH HIGH

Withthisconfigurationofgates,wecanturntheswitchonandoffbasedonSSD’soutput,andkeepitturnedonwhentheLVDtriggersatleastonce.OurpreferredchipforthisisaTexasInstrumentsSN74LVC2G32[16].Thisisadualgatechipwith2-bitgates.Wechosethischipduetoitsreliability,lowcost,andabilitytohaveanoperatingvoltageof3.3V[16].

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Requirements Verifications1. OutputalogicalHIGH3V(+/-5%)

whenSignalStrengthDetectoroutputsalogicalHIGH.

1. UsetheoscilloscopetodetectwhetheraHIGH3V(+/-5%)outputisgeneratedwhentheSignalStrengthDetectoroutputsalogicalhighA. Testthetransitionfromlogical

LOWtoHIGH2. OutputalogicalLOW0V(+/-5%)

whenSignalStrengthDetectoroutputsalogicalLOW,andLowVoltageDetectorhasnotoutputalogicalHIGH3V(+/-5%)yet.

2. Usetheoscilloscopetodetectwhetheralow0V(+/-5%)outputisgeneratedSignalStrengthDetectoroutputsalogicalLOWA. Testthetransitionfromlogical

LOWtoHIGH3. OutputalogicalHIGH3V(+/-5%)

whenLowVoltageDetectoroutputsalogicalHIGH3V(+/-5%),anddoesnotchangeoutputwhenSignalStrengthDetectorchangesvalue.

3. UsetheoscilloscopetodetectwhetheraHIGH3V(+/-5%)outputisgeneratedwhenLowVoltageDetectoroutputsalogicalHIGHA. TeststartingfromSSDlogicalLOWB. TestcontinuingswitchingSSD

logicalHIGHandLOW4. OutputalogicalLOW0V(+/-5%)

whenLowVoltageDetectoroutputsalogicalLOW0V(+/-5%)

4. UsetheoscilloscopetodetectwhetheraLOW0V(+/-5%)outputisgeneratedwhenboththeLowVoltageDetectorandSignalStrengthDetectoroutputaLOW

5. UnabletooutputalogicalLOW0V(+/-5%)oncetheLowVoltageDetectorhasoutputalogicalHIGH3V(+/-5%)atleastonce.

5. UsetheoscilloscopetodetectwhetheraHIGH3V(+/-5%)outputisgeneratedafteraLOW0V(+/-5%)oncetheLowVoltageDetectoroutputsalogicalHIGH,afterithadbeenoutputtingazeroB. TeststartingfromSSDlogicalLOWC. TestcontinuousswitchingSSD

logicalHIGHandLOWD. TestcontinuousswitchingLVD

logicalHIGHandLOW(tosimulatefluctuationofLVDout)

ElectronicSpeedController(ESC)

Part:HobbywingQuicrun60A2S-3SWaterproofBrushedESC

ThepurposeoftheESCinanRCboatistocontrolboththespeedandthedirectionoftheboat.TheESCwillreceiveamessagesignalfromthePulse-WidthModulator.Thiswillbea1kHz

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frequencyandtheencodedmessagewillcommunicatethedirectionatwhichthemotorshouldtravel.TheESCwillbeconnectedtotheexistingDCmotorintheboat.WewillusetheHobbywingQuicrun60A2S-3SWaterproofBrushedESC.WemadethischoiceprimarilybecauseitisoneofHobbywing’swaterproofoptions.Thisoptionisalsohaslow-voltagecut-offforthebattery,operatesat7.2V(compatiblewithourmotor),overheatprotectionforthemotor,andsignallossprotectionforthePulseWidthModulator[17].Thisisalsothemostcost-effectiveoptionwithallofthesefeaturesthatwehavefound.

2.5 SignalUnit

2.5.1OverviewTheSignalUnitisperhapsthemostessentialmoduleoftheproject.Itconsistsoftwomajorparts:TheRelativeSignalStrengthIndicator(RSSI)circuitandaSchmitttrigger.TheRSSIwillbecalculatedthroughtheimplementationofanICwhichsendsinformationthatwillbefilteredbytheSchmittTriggerandfinallyitwillbecommunicatedtothemicrocontroller.Figure5.1showsabasichighlevelblockdiagramofthesignalunitinterface.

Figure5.1:HighlevellayoutoftheSignalUnit

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2.5.2RelativeSignalStrengthIndicatorCircuitTheRSSI(RelativeSignalStrengthIndicator)willbeusedtocalculatethesignalstrengthrelatingtothecurrentpositionoftheboat.Thisisavitalcomponenttohavesinceitwilldeterminewhentheboatneedstoreturntothe‘regionofoperation’.Forthisprojectthe‘regionofoperation’isdefinedtobealocationwherethesignaldetectedisgreaterthan10%ofthemaximumsignalstrength.Unfortunately,sincetheRCboatusedintheboatdidnotcomewithdetailedspecifications,wewillhavetoimplementreal-lifeteststoaccuratelycorrelatedistanceandsignalstrength.Thesetestscanbedoneeasilyusingourhandheldremotecontrollerandtheboatmotor.Wecansimplydoaseriesoftrialanderrortestsandseehowfarawayexactlytheremotecontrollercanstilldrivetheboatmotor.

TheRSSIcircuitwillmonitorthesignalstrengthcorrespondingtotheboat’scurrentlocation.ThiswillbeachievedusingtheAnalogDevices’AD8317chip.TheAD8317takesinanRFinputandoutputsavoltagethatrelatestothesignalstrength(measuredindBm).Figure5.2displaysthebasicpinlayoutschematicwhiletable5.1describestherespectiveconnections.

Figure5.2:SchematicoftheAD8317IC[18]

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Table5.1:PindescriptionsoftheAD8317IC[18]PinNo. Mnemonic Description

1 INHI RFInput,rangingfrom-50dBmto0dBm

2 COMM DeviceCommon,connectedtolowimpedanceground

3 CLPF LoopFilterCapacitor–setspulseresponsetimeandbandwidth

4 VSET Set-pointInput

5 VOUT VoutprovidesadecreasinglinearrepresentationoftheRFsignalamplitude

6 TADJ TemperatureAdjustmentPin(chosentobe8kΩ)

7 VPOS ConnectedtoPowerSupply(3.0to5.5V)

8 INLO RFCommon

Theresistancesassociatedtosomeofthepinsinfigure5.2willvaryaccordingtotheoperationalfrequencyrangeoftheboat.Theremote-controlboatusedinthisprojectoperatesatafrequencyof2.4GHz.Basedonthedatasheet,valuesforeachpartweredetermined.Thetablesreferredtoforthedataanalysisareshownbelowastable5.2andtable5.3.

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Table5.2:Frequencyandresistanceconsiderations[18]

Frequency RecommendedRTadj

50MHz 18kΩ

100MHz 18kΩ

900MHz 18kΩ

1.8GHz 8kΩ

1.9GHz 8kΩ

2.2GHz 8kΩ

3.6GHz 8kΩ

5.3GHz 500kΩ

5.8GHz 500kΩ

8GHz OPEN

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Table5.3:Circuitspecificationsfor2.2GHzfrequencyoperation[18]

Parameter Conditions Minimum Type Maximum Unit

f=2.2GHz RTadj=8kΩ

InputImpedance

810||0.39 Ω||pF

±1dBDemonicRange

TA=25ºC

-40ºC<TA<85ºC

50,48 dB

MaximumInputLevel

±1dBerror -4.00 dB

MinimumInputLevel

±1dBerror -54 dB

Slope -25 -22 -19.5 mV/dB

Intercept 10 14 20 dBm

OutputVoltage(HighPowerIn)

PIN=-10dBm 0.35 0.54 0.80 V

OutputVoltage(LowPowerIn)

PIN=-35dBm 0.75 1.21 1.35 V

TheAD8317willbepoweredbythebatteryusingavoltageregulator(section2.3.3)whichwillneverletthevoltageexceeditsmaximumvoltageratingof5.5V.Lastly,theoutputvoltagewillgodirectlyintotheSchmitttriggerwhichwillthendeterminewhattocommunicatetothemicrocontroller.

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2.5.3SchmittTriggerBysettingathresholdvaluetocompareagainst,theSchmitttriggerwillusetheoutputreceivedfromtheRSSIcircuittodetermineiftheboatneedstoreturntotheregionofoperationornot.TheSchmitttriggerwillusethesameTL331chip[2]usedinthelowvoltagedetectioncircuit.TheTL331willservethepurposeofacomparatorandwillmeasuretheoutputfromRSSIagainstareferencevalue.AschematicoftheSchmitttriggercircuitusedisshowninfigure5.3.

Figure5.3:SchematicoftheSchmitttrigger

DX(MMSZ4681T1G)isa2.4VZenerdiodethatisusedtoregulatethevoltage.TheresistorR1waschosentobea100kW,tosatisfytheminimumcurrentconditionsforthediode.

Basedonthetwocalculationsinequations1and2,itissafetoassumethataresistorvalueofa100kWisasafechoicesinceitagreeswiththeproductspecifications.

ThecomparatorwillusetheoutputfromthevoltagedividerastheinputtoVin-.Thiswillserve

asthethresholdreferencevoltage.Inthiscase,the2.4VZenerdiodewillinputavoltageof2.4VtotheresistorsR2andR3,both1MW,whichwilldivideitinhalf.Consequently,Vin

-,willbefedwithaconstantvoltageof1.2V.

Ascanbeseenfromtable5.3,themaximumvoltageoutputtedwillbe1.21V.Thisvoltageisassociatedwiththeweakestsignal,whichcanbeconfirmedbythefigureA.1,presentintheappendix.Vin

+willreceiveitsinputfromtheRSSIrangingfrom0to1.21V(table5.3)with0Vindicatingthemaximumsignalstrength.Uponsimulation,thecircuitinFigure5.4gaveustheoutputshownintable5.4andfigure5.4.

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Table5.4:SchmitttriggercircuitsimulationresultsVin+ Output0 LOW0.2 LOW0.4 LOW0.6 LOW0.8 LOW1.0 LOW1.2 HIGH

Figure5.4:Schmitttriggercircuitsimulationresults

Thesimulationresultsverifythatthecircuitwilloutputahighassoonasalowlevelsignalisdetected.Finally,thisHIGH/LOWoutputwillgointothemicrocontrollerwhichwillthendeterminehowtoproceed.

Note: Figure5.4usesaconsistentoutputvoltageof3.3Vtomakethegrapheasiertointerpretandunderstand.Inreallifeexperimentation,thevoltagewillrangefrom4.5to9VduetothefactthatVCCisconnecteddirectlytothebattery.Sincetheinputthatthemicrocontrollerreceivesisadigitallogicinput,thevalueofthevoltageitselfwillnotmatter(allvoltagesrangingfrom4.5Vto9VwillresultinthesameoutputofaHIGH);unlessitis0orveryclosetoitwhichcorrespondstoaLOW.

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Requirements Verifications1. Outputa:

A. logicHIGHtothemicrocontrollerwhentheRSSIoutputisgreaterthanorequalto1.2V(+/-5%).

B. logicLOWtothemicrocontrollerwhentheRSSIoutputislessthan1.2V(+/-5%)

1. Useadcpowersupplytopowerthecircuitandthenusetheoscilloscopetodetectif:

A. aHIGHoutputisgeneratedwhenthevoltageacrossR4,1MW,isgreaterthanorequalto1.2V(+/-5%)(figure5.3)

B. aLOWoutputisgeneratedwhenthevoltageacrossR4,1MW,islessthan1.2V(+/-5%)(figure5.3)

2.5.4SensorPart:XtrinsicMAG3110

Forthesensorunit,wewillbeusingonesensor,amagnetometer.Amagnetometerisusedtocalculateyourdirectionwithregardstothemagneticpolesoftheearth.Byusingthiswecanaligntheboatinaccordancetothedesiredheading.Magnetometershave,onaverage,averylongOutputDataRate(ODR)comparedtotherestofthedigitalaspectsofthisproject.Mostcost-effectiveoneshaveapproximately80HzODR[12,13].Thiswouldnormallybeabottleneck,butbecauseofthecomplexityoftheotheroperationsinthecircuit,weareabletooptimizereadingthemagnetometerinthemicrocontroller.ThissensormustoperateatavoltageofVCC

(3.3V).ItmustalsouseI2CcommunicationbecauseofthefewerI/Oportsrequiredandafasterreadspeed.Lastly,thissensormustbeabletobepolled.Theoptimizationthemicrocontrollerwilltakecanonlybeachievedifitisabletoprocessinstructionswhilethemagnetometerisgettingitsdataready.

Somemagnetometerscalculatedirectionbasedontheaverageofseveralsamples.Thisisdesirableforusbecauseitwouldreduceerror.However,manyofthemagnetometersthatdothisaresignificantlymoreexpensivesoitisnotastrictrequirement,suchastheHoneywellHMC5883L[12].

XtrinsicMAG3110isthemostcosteffectiveoneforourneeds.Thisunitischeaperthanmanycompetitors[12,14,15]Duetothepresenceof“DR_STATUS”thischipisabletobepolledtoseeifthedataisready.CombiningthiswiththeslowerODRmeansthatwecandomanycalculationoptimizationsbasedonwhenthisdataisready

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2.5.5AntennaArrayPart:TexasInstrumentsCC2500RGPR

WehavechosentheTexasInstrumentsCC2500RGPRbecauseofitslowcost,availability,andsatisfactionofourneeds.Itisatransceiver.Wewillbeorderingseveralofthese,mostlikely6.Wehaveconstructedatestingmethodologytodecidewheretheantennasneedtobe,basedonasetofexperimentsdoneinSlovenia.Tocalculateangleofarrivalwewillbeusingthealgorithmdocumentsonpage240and241ofAngleofArrivalestimationalgorithmsusingReceivedSignalStrengthIndicator[20].Wewillstartbyplacingthetransceiversaroundonacircularboardwithdiameter5cm.Wewillplacethematvariouspointsallevenlyseparated.Usingdifferentdistancestodiscoverthepositionthatwillgiveusasmosta+/-10-degreeerrorforangleofarrival.Wewillplacethisantennaarrayontheground,andtestit’sreadingsfromdistancesof1mto30m.Wewillalsobetestingforangles,inincrementsof20degreesfrom0to360[20].

Requirement Verification1. Algorithmestimatesangleofarrival

within10degreesoftruevalue.1. Use6antennastocreateanantenna

arrayinavariationofahexagon.Tryvariousdistancesfrombeing1cmto3cmapart.Testestimatedangleofarrivalusingthealgorithmdocumentedintheaforementionedpaper.

3 ToleranceAnalysisThehighestriskinourdesignisgoingtocomefromtheSignalUnit.Signalcanbeinterferedwithbynumerablethingssuchasrainortheradiationfromthesun.Thisinterferencecanaffecttheaccuracyofthesignal,addingerrorintothecontrolsystem.Withoutthesignaldetectionworkingperfectly,wehavenoreferenceofwherewearecomparedtoourstartinglocation.Lastly,ifthedataisflawedwewillwastepoweringuidingtheboatinthewrongdirection.However,wewillmitigatealloftheserisks.Onesolutionistousesixantennasignalsinsteadofone.Thiswillmakethesignalmuchmoreaccurateandreducetheinterferencefromsolarradiation.Thiswillalsogiveusaproperestimatedangleofarrival.Wewillbetestingavarietyofantennaconfigurationstofindthebestpossibleone.

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4 CostsTable6.1:LaborCosts

Engineer HourlyRate HoursInvested Total=HourlyRatexHoursx2.5

GrantEverett $30.00 250 $18,750SomakGhosh $30.00 250 $18,750ZainZaman $30.00 250 $18,750Total $30.00 250 $56,250

Table6.2:PartsCosts

Item PartNumber Cost(PerUnit)

Amount TotalCost

Power

ZenerDiode2.4V

MMSZ4681T1G $0.03 2 $0.06

ZenerDiode3.3V

MMSZ4684T1G $0.03 1 $0.03

1mΩResistor 691585 $0.10 10 $1.00100kΩResistor 691340 $0.10 10 $1.00Comparator TL331 $0.17 2 $0.34DuracellBattery AA1.5VMN1500 $5.99 3 $17.97Control HobbywingQuicrun

60A2S-3SWaterproofBrushedESC

$20.99 1 $20.99

Microcontroller ATMEGA328PB-AU-ND

$1.38 1 $1.38

SensorMagnometer

NXPUSAInc.MAG3110FCR1

$2.12 1 $2.12

Signal SignalStrengthDetector

AD8317 $6.75 1 $6.75

47nFCapacitor 15253 $0.19 1 $0.19100pFCapacitor

80-C333C101KDG5Ta

$1.70 1 $1.70

8kΩResistor 661036 $0.39 1 $0.391kΩResistor 660877 $0.39 1 $0.39

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Antenna TexasInstrumentsCC2500RGPR

$2.91 6 17.46

Total $62.77

4.3TotalCosts

TotalCost=Parts+Labor=$56,312.77

5 SchedulesWeek Task Delegation2/6–2/12 WorkonProjectProposal Grant

WorkonProjectProposal SomakWorkonProjectProposal Zain

2/13–2/19 WorkonProjectProposal,SignupforMockDesignReview,FinishEagleCad

Grant

WorkonProjectProposal,SignupforMockDesignReview,FinishEagleCad

Somak

WorkonProjectProposal,SignupforMockDesignReview,FinishEagleCad

Zain

2/20–2/26 WorkonDesignReviewDocument,SignupforDesignReview

Grant

WorkonDesignReviewDocument,SignupforDesignReview

Somak

WorkonDesignReviewDocument,SignupforDesignReview

Zain

2/27–3/5 DesignReview&OrderParts GrantDesignReview&OrderParts SomakDesignReview&OrderParts Zain

3/6–3/12 Build&testPCL GrantDesignState-SpaceSystem&CreateSimulinkforController

Somak

BuildtheLVDC Zain

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3/13–3/19 CodeMicrocontroller GrantDesignState-SpaceSystem&CreateSimulinkforController

Somak

BuildtheLVDC Zain3/20–3/26 ConfigureRFReceiver Grant

ConfigureRFReceiver SomakBuildtheLVDC Zain

3/27–4/2 BuildMicrocontrollerPCB GrantBuildtheSSDC SomakBuildtheSSDC Zain

4/3–4/9 IntegrateControlUnitwithSomak

Grant

BuildtheSSDC SomakBuildtheSSDC Zain

4/10–4/16 Integrateallparts GrantIntegrateallparts SomakIntegrateallparts Zain

4/17–4/23 FinalChanges&MockDemo GrantFinalChanges&MockDemo SomakFinalChanges&MockDemo Zain

4/24–4/30 Demo GrantDemo SomakDemo Zain

5/1–5/7 WriteFinalPaper GrantWriteFinalPaper SomakWriteFinalPaper Zain

6Ethics&SafetyThereareseveralethicalguidelinesfromtheIEEECodeofEthicswhichapplytoourproject.Wewillfollowtheseguidelinesascloselyaspossible.Theguidelinesinclude–tobehonestregardingallcollecteddata[19],rejectbriberyfromanysource[19],undertaketechnologicaltasksonlywiththerequiredcompetenceandsafetyknowledge[19],nottoengageinanyactsofdiscrimination,andassisttheprofessionaldevelopmentofourpeers[19].Thismeansthatwewillworktowardsbuildingourentireprojectwithoutanyoutsidehelp,andundertherulesoftheclass[19].Wewillalsopurchaseseveralcomponentsofourdesign,howeverwewillindividuallybuildamajorityofourdesignuniquelyandindependently.Whendiscussingwithouradvisorandtheprofessorsoftheclasswewillalwayspresentaccuratedataandtruthfully

30

presentourprojectregardlessofitsfunctionality[19].Lastly,wewilladheretoallsafetyguidelinesandtakeeveryprecautionnecessarytosafelytestourboat[19].Ourboatwillhaveelectricalcomponentsandwillneedtohaveseveralextraprecautionstakentomakeitsafeforthegeneralcommunity.Wewillalsonotdiscriminateintheuseofthisboatortheboattechnologyamongstanyone(saveforyoungchildrenwhowillneedsupervision).

Thereareseveralsafetyguidelinesthatwewilladheretocloselyaswell.First,wewillfollowallofthegivensafetyguidelinesputforthbyECE445,ECEIllinois,andtheUniversityofIllinoiswhileusingthelaboratoryequipment.Seeingthatwearealsomodifyingachildren’stoywithelectronicsthatwillbeonthewaterwewilltakeprecautionswhentestingsuchastestingasagroup,testinginemptyopenwater,andthoroughlyworkingtowaterprooftheboat.Theboatwillhavemanyelectricalcomponentswhichwewillhavetomakesurewillnotbedangerousinthewater.Wewilluseamarine-gradeepoxywhichwillbeusedtore-sealpre-existingelectricalcomponentsandsealallnewelectricalcomponentswithinthehulloftheboat.

Therearenoexistingregulationsformodifyingreplicaboats,however,theredoesexistaNorthAmericaModelBoatAssociation(NAMBA).Thisgoverningbodyhassafetyregulationsaboutracingmodelboats.Ifthereisoverlaponanyofthetechnologyonourboatwiththeirstandardmodelboat,wewilladheretotheirregulations.Currently,

Fortesting,wehavecontactedtheActivitiesandRecreationCenteroncampusandwilllookforapprovaltosafelytestthere.

31

References

[1] “Duracell Coppertop MN1500.” https://d2ei442zrkqy2u.cloudfront.net/wp-content/uploads/2016/03/MN1500_US_CT1.pdf [Feb. 21, 2017]

[2] “TL 331 Single Differential Comparator.” http://www.ti.com/lit/ds/symlink/tl331.pdf , Jan. 2015 [Feb. 21, 2017]

[3] “Zener Voltage Regulators.” http://www.onsemi.com/pub_link/Collateral/MMSZ4678T1-D.PDF, Nov.2013[Feb. 21, 2017]

[4] Atmel, “ATmega328P”, 2016, Available: http://www.atmel.com/Images/Atmel-42735-8-bit-AVR-Microcontroller-ATmega328-328P_Datasheet.pdf [Feb. 22, 2017]

[5] Digi-Key, Microchip Technology ATMEGA328PB-AU, 2017, Available: http://www.digikey.com/product-detail/en/microchip-technology/ATMEGA328PB-AU/ATMEGA328PB-AU-ND/5638812 [Feb. 22, 2017]

[6]“L4931”https://cdn-shop.adafruit.com/product-files/2166/2166datasheet.pdf,Oct.2013[March10,2017]

[7] Xtrinsic, “Xtrinsic MAG3110 Three-Axis, Digital Magnetometer”, 2013, Available: http://cache.freescale.com/files/sensors/doc/data_sheet/MAG3110.pdf [Feb. 22, 2017]

[8] avrProgrammer, ATmega328p Power Consumption, Available: https://www.avrprogrammers.com/howto/atmega328-power [Feb. 22, 2017]

[9]EvanWallace,“FiniteStateMachineDesigner”,2010,Available:https://www.cefns.nau.edu/~edo/Classes/CS315_WWW/Tools/fsm.html[Feb. 22, 2017]

[10]Creately,Available:https://creately.com/app/?tempID=gc7qvpsj1&login_type=demo#[Feb. 22, 2017]

[11]Nexperia,“74HC2G32;74HCT2G32”,Available:http://assets.nexperia.com/documents/data-sheet/74HC_HCT2G32.pdf[Feb. 22, 2017]

[12] Honeywell, “3-Axis Digital Compass IC HMC5883L”, 2010, Available: https://cdn-shop.adafruit.com/datasheets/HMC5883L_3-Axis_Digital_Compass_IC.pdf [Feb. 22, 2017]

[13] Digi-Key, “NXP USA Inc. MAG3110FCR1”, 2017, Available: http://www.digikey.com/product-detail/en/nxp-usa-inc/MAG3110FCR1/MAG3110FCR1CT-ND/3524267 [Feb. 22, 2017]

[14] Xtrinsic, “Xtrinsic MAG3110 Three-Axis, Digital Magnetometer”, 2013, Available:

http://cache.freescale.com/files/sensors/doc/data_sheet/MAG3110.pdf [Feb. 22, 2017]

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[15] Digi-Key, “Memsic Inc. MMC34160PJ”, 2017, Available: http://www.digikey.com/product-detail/en/nxp-usa-inc/MAG3110FCR1/MAG3110FCR1CT-ND/3524267 [Feb. 22, 2017]

[16] Texas Instruments, “SN74LVC2G32 Dual 2-Input Positive-OR Gate”, 2015, Available:

http://www.ti.com/lit/ds/symlink/sn74lvc2g32.pdf [Feb. 22, 2017].

[17]“HobbywingQuicrun60A2S-3SWaterproofBrushedESCfor1/10.”https://hobbyking.com/en_us/hobbywing-quicrun-60a-2s-3s-waterproof-brushed-esc-for-1-10.html[Feb. 22, 2017]

[18] “Analog Devices AD8317.” http://www.analog.com/media/en/technical-documentation/evaluation-documentation/AD8317.pdf [Feb. 22, 2017]

[19] "IEEE IEEE Code of Ethics." IEEE - IEEE Code of Ethics. N.p., n.d. Web. 08 Feb. 2017. http://www.ieee.org/about/corporate/governance/p7-8.html

[20] “Angle of Arrival estimation algorithms using Received Signal Strength Indicator” – Marko Malajner, Dusan Gleich, Peter Planinsic, 2015. http://www.dlib.si/stream/URN:NBN:SI:DOC-O4FYKB1C/e39456e9-60ae-4cc1-b4dd-9ee7e73f2b53/PDF [Mar. 16, 2017]

[21] Digi-Key, “TexasInstrumentsCC2500RGPR”, 2017, Available: http://www.digikey.com/product-detail/en/texas-instruments/CC2500RGPR/296-38562-2-ND/4695539 [Mar. 16, 2017]

33

Appendix

FigureA.1:AD8317VOUTvsPIN

FigureA.2:AD8317PinLayoutexample