Post on 23-May-2018
ImplementationofanAnalog
MultiplexerforXilinxSpartan3e
StarterBoard
by
FrankScarfo
SeniorProject
COMPUTERENGINEERINGDEPARTMENT
CaliforniaPolytechnicStateUniversity
SanLuisObispo
2009
i
TableOfContents
ListofFigures....................................................................................................................................... iiAcknowledgements ..........................................................................................................................iiiI. Introduction .................................................................................................................................. 1II. Background.................................................................................................................................. 2III. Requirements ............................................................................................................................ 5IV. DesignandDevelopment...................................................................................................... 6AnalogMultiplexerHardware.................................................................................................. 6AnalogMultiplexerSoftwareInterface ................................................................................ 7ExternalStorageSystemDesign ............................................................................................. 8
V. SystemTesting......................................................................................................................... 14CurrentStateofSystem ........................................................................................................... 15
VI. Conclusion................................................................................................................................ 19VII. Bibliography .......................................................................................................................... 21VIII. Appendix................................................................................................................................ 22A.MUX.h–MUXControlAlgorithmHeaderFile ........................................................... 22B.MUX.c–MUXControlAlgorithmSourceCode.......................................................... 22C.Lcd.h–LCDControlHeaderFile ..................................................................................... 23D.LCD.c–LCDControlSourceCode................................................................................... 24E.Timer.h–TimerControlHeaderFile ............................................................................ 28F.Timer.c–TimerControlSourceCode........................................................................... 28G.Leds.h–LEDControlHeaderFile................................................................................... 29H.main.c–SampleControlAlgorithmSourceCode.................................................... 29I.spi.h–SPIControlHeaderFile.......................................................................................... 32J.spi.c‐SPIControlSourceCode ......................................................................................... 33K.EmbeddedSystemBlockDiagram................................................................................. 37L.AnalysisofSeniorProjectDesign ................................................................................... 38
ii
ListofFigures
Figure1:Spartan3EStarterBoard ............................................................................................ 3
Figure2:SimplifiedAnalogMultiplexerHardwareLayout ............................................. 7
Figure3:DigilentPMOD‐SDSecureDisk(SD)CardModule ........................................... 9
Figure4:SDCardSPIModeInitializationSequence........................................................ 10
Figure5:SampleSuPERMemoryInterface ......................................................................... 11
Figure6:DigitalOutputsMemoryDetail .............................................................................. 11
Figure7:SampleControlAlgorithmSoftwareFlow ........................................................ 12
Figure8:DigilentPMOD‐SF16MegabitSerialFlashROM............................................ 17
iii
Acknowledgements
IwouldfirstliketothankProfessorJamesHarrisforallowingmetotake
partinsuchaninterestingproject,andforhissupportandguidancealongthe
way.IwouldalsoliketothankMattStaniszewskiandKhanhNguyenfortheir
assistanceindevelopingembeddedsystemsfortheSpartan3eBoard.Finally,I
wouldliketothankTonyWonsyld,whoseproofofconceptofanAnalog
MultiplexerfortheSuPERsystemprovidedasolidfoundationtoimplementmy
system.
1
I. Introduction
TheCalPolySustainablePowerforElectricalResources(SuPER)project,
startedbyProfessorJamesHarrisin2005,soughttoprovidealow‐costmethod
ofprovidingpowertopeopleindevelopingcountries.Thesecountriesoftenlack
thebasicnecessitiestosupporttheirday‐to‐dayoperations.Theystruggleto
providethesimpleamenitiessuchaslighting,waterpumps,refrigeration,and
powertorunvarioustoolsthatweoftentakeforgranted.Insteadofwaitingfor
governmentsandlargecorporationstoprovidethisnecessaryinfrastructure,
theSuPERprojectaimstoprovideasustainable,costeffectivesolutionfora
singlefamilyorvillagetopurchaseindependently.
Inrecentyears,aprototypehasbeendeveloped,whichcenterson
harnessingsolarenergytoprovidepowertonumerousloads.Thisprototypeis
constantlybeingimprovedtoreducecosts,improveefficiency,andextendthe
system’soperationallifetime.Whilethecostofnewtechnologiesthatarebeing
usedtodevelopthissystemremainfairlyhigh,inthenearfuturethesecostsare
expectedtodropsignificantlyastechnologiesandconstructionmethods
improve.
2
II. Background
CurrentlytheSuPERprototypeconsistsofaphotovoltaicpanelthatisusedto
chargeabattery,whichinturnisusedtopowerseveralDCloadsincluding
motors,refrigerationunitsandlightingsystems.Thiscomplexsystemrequires
precisecontroltoregulatehowthebatteryischargedanddischarged.This
intricatecontrolallowsforlongerbatterylifetimes,andsafelyregulatesthe
loads.
Inthepast,theSuPERprototypewascontrolledusingaDelllaptopandaPIC
Microcontroller.Whilethissystemisabletoexceedtherequirementsofthe
system,itisexpensivetoimplement,anddrawsalargeamountofpower
(approximately60watts).Itbecameclearthatalowcost,lowpowersolution
wasrequirediftheSuPERprojectwastoreachit’sgoalofbeingaffordablefor
thecommonfamilyinanunderdevelopedcountry.
Afteranalyzingseveraloptions,itwasconcludedthattheXilinxSpartan3e
StarterBoard(seeFigure1)supportedmanyoftherequirementsforcontrolling
theSuPERproject,andcostslessthatonehundredandfiftydollars.Notonly
doesthissignificantlycutoverallsystemcost,butalsoreducesthepowerusage
toonlyaboutonewatt.AfterrealizingthevalueofswitchingtotheSpartan3e
board,thecorestepsofimplementingthesystemweredeveloped.These
includedanembeddedLinuxdistributioncalleduClinuxtorunontheFPGA,and
3
applicationstotakeinputfromakeyboardandoutputtoadisplay.These
projectsformthefoundationonwhichtheSuPERcontrolsystemwillrun,but
stilllacksomefunctionalitytomeetalloftheneedsoftheprototype.
Figure1:Spartan3EStarterBoard
Inordertoimplementthesemissingcapabilities,twosystemsneededtobe
developed,thefirstofwhichbeingawaytomultiplextheinputsandprovidethe
appropriateoutputs.TheSpartan3eFPGAoffersalimitednumberofpinstobe
usedasinputsandoutputs,farlessthatrequiredtomanagealloftheswitches
4
andsensorsnecessarytocontroltheSuPERprototype.Tocombatthisproblem,
TonyWonsyldprovedthatitwaspossibletomultiplexthenumeroussystem
inputsthroughtwoanalogmultiplexers.Thisdrasticallyreducesthenumber
pinsrequiredfromover50downto20(5SPIsignals,4multiplexerselectlines,
10digitaloutputs,and1PWMoutput).
Thissystemmadeuseoftheonboardflashmemorytostorethetime
stampedinputdata.ThismemoryhoweverwillbeoccupiedbytheuClinux
installationontheboard,makingitnecessarytointegrateanewmemorydevice
tothesystem.Thisdataisextremelyvaluableforbothperformanceanalysisand
failurediagnosis,andanalternativestoragemethodwillneedtobedeveloped.
5
III. Requirements
ThisprojectexpandsonTonyWonsyld’sprojecttoimplementtheanalog
multiplexerdesignhepreviouslyvalidated.Thissystemissubjecttoseveral
strictrequirements:
• Systemmustbeabletosupportupto32inputstoallowforinclusionof
additionalsensorsofcurrentsystem
• SystemmustbeabletooutputappropriatePWMandapproximately10
digitalcontrolsignals
• Systemmustreacttoharmfulloads(suchascurrentoverload)withinone
millisecond
• LogandDisplayappropriatesystemfeedback
• Performallrequirementswithinonetenthofasecond.
6
IV. DesignandDevelopment
Thedesignofthissystemtookplaceinseveraldistinctparts.Theseincluded
developingthehardwaretocontroltheanalogmultiplexers,creatingasimple
softwareinterfacetothemultiplexers,designingawaytostoredata,and
implementingasamplecontrolalgorithmtodemonstratethesystem
capabilities.
AnalogMultiplexerHardware
Thefirststepinintegratingtheanalogmultiplexerswastolayoutthe
hardwareforthesystem.ThiswasdoneonaDigilentFX2Breadboard,which
connectsintotheon‐boardFX2connector.Thisboardprovidesaquick,simple
waytolayoutandmodifythehardwareandinterfaceitwiththeSpartan3e
Board.Thehardwareisfairlysimpletoimplement,andrequiresveryfewpins.
FourpinsareusedtocontrolwhichsignalsarebeingpassedthroughtheMUX,
and5pinsareusedtocontrolbothoftheanalogtodigitalconverters.
7
Figure2:SimplifiedAnalogMultiplexerHardwareLayout
AnalogMultiplexerSoftwareInterface
Afterthehardwaredesignwascomplete,itwasnecessarytoprovidea
simpleinterfacetocontrolbothMUXsandADCstoreadinthesensorandswitch
data.Thiscontrolwasbrokendownintoseveralfunctions:
voidinitMUX()
Thisfunctionshouldbecalledbeforeanyothercallsaremade.It
initializesalloftheappropriatepinstobeoutputsandinitializesthe
SerialPeripheralInterface(SPI)tocommunicatewiththetwoon‐board
analogtodigitalconverters.
8
voidnextInput()
ThenextInputfunctioncontrolstheMUXselectlinestoiteratethroughto
thenext2sensorsconnectedtoeachMUX.Thisfunctionshouldbe
followedbyacalltoreadInput().
unsignedlongreadInput(intadcNum)
readInputactsasawrappertothefunctionsinspi.ctoallowforasimpler
userinterface.Ittakesasingleargument,whichspecifieswhichADC
shouldbereadfrom.
ExternalStorageSystemDesign
AfterresearchingnumerouspossibilitiesforinterfacingtheSpartan3ewitha
non‐volatileexternalmemorydevice,wedecidedthattheDigilentPMOD‐SD(see
Figure3)wouldbestfitoursystem.ThePMOD‐SDisamodulethatallowsa
SecureDisk(SD)cardtobeconnectedtotwoofthejumpersontheSpartan3e
board.Thisdesignwouldallowfor2GBofeasilyremovablememorythatcould
bepluggedintoaSDcardreadertobeanalyzedonaPC.
9
Figure3:DigilentPMODSDSecureDisk(SD)CardModule
SDcardscanusetwodifferentinterfacesforcommunication:SDcardmode,
andSPImode.Bothofthesemodesarecommandandresponsetypeinterfaces
wherethemastersendsaseriesofbytestothecardspecifyinganactiontobe
performed,thenwaitsforaconfirmation.WhiletheSDcardusesseveraldata
linestocommunicatemakingtransfersmuchfaster,itutilizesamuchmore
complicatedcommunicationprotocol,andcanonlywriteblocksof512bytesata
giventime.Afterensuringtheslowercommunicationspeedwasacceptable,it
wasdecidedthattheSPIinterfacewouldbeused.
Thefirststepinusingthecardwastoinitializethecard.Thisprocess
involvessendingthecardseveralcommandstocheckthevoltagelevelssupplied
tothecard,transferthecardtoSPImode,andtosetthetransferblocksize(see
Figure4).Thisstepiswheremysystemrepeatedlyfailed,asitwasunabletoget
anyresponsesfromthecardtoverifyitwasreceivingcommands.Aftertesting
theSPIwithanoscilloscopetoverifythatthesignalswerereachingthecard,it
becameapparentthattheissuewasduetotheSPItiming.Inthefreeversionof
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theSDCardAssociation’sSDCardSpecification,thetimingdiagramsare
purposelyleftblank.AfternumerousmodificationstotheSPItoattempttofind
thecorrectcommunicationprotocol,Iwasunabletosuccessfullycommunicate
withthedevice.Inordertocorrecttheissues,itwouldlikelybenecessaryto
payforthespecification,whichcostsseveralthousanddollars.Itwas
determinedthatthiswasprohibitivelyexpensive,asotheroptionsexistata
moreaffordableprice(seeRecommendations).
Figure4:SDCardSPIModeInitializationSequence
DuetotheissuesintegratingtheSDcardintothesystem,atemporary
solutionwasused,storingthedatainanarrayintheon‐boardBRAMmemory.
Whilethisimplementationisnotidealduetoit’ssmallsizeandvolatiledesign,it
demonstratesthememorystructuretobeusedtointerfacewithotherprojects
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suchasthedataparserdevelopedbyKhanhNguyen.Thisinterfaceisdesigned
toefficientlyutilizethelimitedspaceavailablebynotstoringtimestamps.
Instead,thedataisstoredinconsecutiveblocksof68bytes,twobytesforeachof
the32sensors,twobytesforthePWMdutycycle,andonebitforeachdigital
output.Alldatashouldbestoredinthestructureshownbelow.Eachofthese
blocksisasettimeapart(typicallyonetenthofasecond),allowingadataparser
toquicklydeterminewhenasampleoccurredbymultiplyingtheblockoffsetby
theconstantsampletime.AnynewmemorysystemintegratedintotheSuPER
systemshouldstrivetokeepthisinterfaceintact.
Figure5:SampleSuPERMemoryInterface
Figure6:DigitalOutputsMemoryDetail
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SampleControlAlgorithm
Thefinalcomponentofthedesignisasamplecontrolalgorithmtotestthe
multiplexingoftheinputsandtosimulatethegenerationofappropriateoutputs.
Thisalgorithmconsistsoftwomaincomponents:themainroutine,andthe
interruptroutine(seeFigure7).
Figure7:SampleControlAlgorithmSoftwareFlow
ThemainroutinefirstinitializesallnecessarycomponentssuchastheMUX
controlandtheLCDscreen,thenentersaninfiniteloopwhereitpollstheinputs,
thedataandstoresthemintoanarray.Pollingtheinputsallowsformoretime
criticalapplicationssuchascontrollingthePWMtobecontrolledinthe
interruptserviceroutine.
13
Theinterruptserviceroutine(ISR)iscalledbyaninterruptgeneratedbythe
timercore,andhastworesponsibilities.First,thevoltageoftheoutputPWM
signalisvariedtoproducethecorrectdutycycle.Next,theISRdeterminesifitis
timetorecalculatethedutycycleofthePWMsignalanddeterminetheother
digitaloutputs.Thisrecalculationrunseverytenthofsecondtoquicklyrespond
tovaryingloadsonthesystem.Currently,thisrecalculationinvolveschecking
allofthesensorsforvaluesgreaterthanathresholdvoltage,andeither
incrementingordecrementingthedutycyclebasedonwhichinputwasselected.
Tosimulateseveraldigitalcontrolsignals,theon‐boardLEDswereusedtoshow
samplesysteminformation.
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V. SystemTesting
Testingofthesystemstartedwithverifyingthetheoreticalworkperformed
byTonyWonsyld.Tony’sworkprovedthatthedesignimplementedinthis
paperwascapableofsupportingtheSuPERsystem.Inordertoverifyhis
calculations,theywerefirstcheckedagainsttheSpartan3Emanualtoensure
thecorrectvalueswereused.Then,hisestimationsonvaluessuchasthelength
oftheinterruptroutinewerecomparedtothoseoftheactualsystemtoensure
theywerereasonablyclose.
Afterthetheoreticalworkwascomplete,thenextstepinvolvedtesting
smallcomponentsofthesystem,andgraduallycombiningthemtogetherwhile
verifyingtheircorrectoperation.FirstamultimeterwasusedtotesttheMUX
controlsoftwareinterfacebyverifyingthecorrectselectline.Afterthistestwas
completed,theoutputfromtheMUXwasconnectedtoeachofthetwoanalogto
digitalconverters,anddummyvoltageswereconnectedtoseveraloftheMUX
datainputslines.Asoftwaretimerwasusedtorepeatedlyiteratethrougheach
ofthe16selectlines,anddisplayeachofthesampledvoltagesontheLCD
screen.Thissetupwasrunforseveralhourstoensuretherewerenotheat
issuesthatwoulddamagethehardware.Afterverifyingthecorrectvoltages
werebeingcapturedandtherewerenoheatissues,thenextstepinvolved
verifyingthatthedummycontrolalgorithmwouldoutputthecorrectPWM
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signalgivendummyinputs.ThiswasdonebyhookingupthePWMsignaltoan
oscilloscopeandobservingtheoutputdutycyclewhilevaryingtheinputs.
Finally,severaltestsweredonetoverifythatallofthetimingrequirements
couldbesuccessfullymet.Thefirsttimingtestwasdesignedtoensurethatall
32sensorscouldbesampledquicklyenoughtomeettherequirementofreacting
toharmfulsensorfeedbackinlessthanonemillisecond.Todeterminethis,a
counterwasusedtomeasurehowmanytimesasensorcouldbereadovera30
secondperiodtodeterminetheaveragetimefortheMUXtocyclethroughall32
sensors.Asimilarmethodwasusedtoensurethatwhileperformingallother
operationsofthesystem,outputvaluescouldberecalculatedatleast10timesa
second.Allofthesetestswerecompletedsuccessfully,leadingtotheconclusion
thattheAnalogMUXdesignissuitableforuseintheSuPERsystem.
CurrentStateofSystem
Duringthefinalstagesofcreatingademoofthesystem,avoltagedivider
wasusedtoprovideseveraldifferentvoltagelevelstoactassensordata.The
systemwasleftrunningforseveralhourswhilesmallchangeswerebeingmade
tothesamplecontrolalgorithm.Duringthisperiod,themultiplexersbecame
extremelyhot,beyondthepointoffailure.Whileinvestigatingthecause,it
seemsseveralofthegroundlineswereincorrectlyplaced,leadingto
unintentionalvoltagedifferentials.Becauseseveralendurancetestshadalready
beenperformed,itseemsthiswasaminorwiringmistakeanddidnotindicate
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Recommendations
WhilethedevelopmentofanSDcarddriverwasunabletobecompleteddue
toalackofnecessarydocumentation,thereareothermethodsthatmayallow
thecardstobeused.ThesimplestmethodofintegratingtheSDcardintothe
systemistofindanappropriateuClinuxdrivertohandlethelowlevel
communicationbetweendevices.Thiswouldallowthedatatobewrittenand
readfromthecardasifyouwereaccessingalocalfile.
IfitisnotpossibletofindasuitableLinuxdriver,thenanotherpossible
solutioncouldbeaDigilentPMOD‐SF.Thismoduleconnects16MbitSerialFlash
ROMtotheSpartan3ethrougha6‐pinjumper.Whilethismoduleoffers
significantlylessmemory,itrequiresamuchsimplerSPIinterfaceandsixfewer
pinstoimplement.
Figure8:DigilentPMODSF16MegabitSerialFlashROM
Witheitheroftheseoptions,anefficientmethodofstoringdataonthe
memorydevicemustbeusedtoallowlongperiodsworthofdatatobestored.
18
ForeaseinintegrationwithotherSuPERprojectssuchasKhanhNguyen’sdata
parser,itisrecommendedthattheinterfacepreviouslyspecifiedbeused(See
ExternalStorageSystemDesign).
Oncethisissuehasbeenaddressed,theSpartan3eStartBoardwouldfulfill
allrequirementsfortheSuPERproject,andwouldbereadyforintegrationinto
theprototype.ThiswouldinvolveinstallingtheMUXcontrolprogramintothe
uClinuxoperatingsystem,andimplementingafullyfunctionalcontrolalgorithm.
Voltagedividerswouldthenbeneededtobringthevoltageofthevarioussystem
sensorsintotherangeof0‐3.3volts.
19
VI. Conclusion
ThescopeofthisprojectinvolvedimplementinganAnalogMultiplexerto
managetheinputdatatotheCalPolySustainablePowerforElectricalResources
(SuPER)project.Thiswouldserveasoneofthefinalstepsnecessarytoport
controloftheprojectfromaDellLaptoptoaXilinxSpartan3eStarterBoard.By
makingthisreplacement,weareabletonotonlycutoverallsystemcost,butalso
reduceourpowerconsumptiontolessthat2%oftheoriginaldesign.
Theimplementationofthisdesignsucceededinmeetingmanyofthe
followingrequirementssetbytheoriginaldesigners:
• Systemsupportsupto32analoginputs
• SystemsupportsonePWMand10digitaloutputsignals
• Systemcanreacttoaharmfulloadinlessthatonemillisecond
• Capabledisplayingappropriatesystemfeedback
• Performallrequirementswithinonetenthofasecond.
Despitethesuccessofmeetingthemajorityofrequirementsofthesystem,
wearemissingonecrucialcomponentthatmustbeaddressed,theabilitytolog
datatoanon‐volatilememoryforanalysisandtroubleshooting.Thispaper
makesseveralrecommendationsforaddressingthisissuethatshouldbe
stronglyconsideredtocontinue.
20
Hopefully,thispaperandthesoftwaredevelopedoverthelifetimeofthis
projectprovetobeusefultoolsforthosewhocontinuetodevelopthisincredible
project
21
VII. Bibliography
SDCardAssociation,“SDSpecificationsPart1PhysicalLayerSimplified
Specification”.http://www.sdcard.org/developers/tech/sdcard/pls/.
Accessed2/1/08
Foust,F,“SecureDigitalCardInterfaceforMSP430”.
http://www.cs.ucr.edu/%7Eamitra/sdcard/Additional/sdcard_appnote_fous
t.pdf.Accessed2/15/09
TonyWonsyld,"ProofofConceptImplementationwiththeSpartan3e
EvaluationBoardfortheCalPolySuPERProject".
http://courseware.ee.calpoly.edu/~jharris/research/super_project/tw_sp.p
df.Accessed1/10/09
BrianEstradaandPatrickMariano,"DevelopmentofUCLinuxPlatformforCal
PolySuPERProject".
http://courseware.ee.calpoly.edu/~jharris/research/super_project/be_pm_s
p.pdf.Accessed5/20/09
KhanhNguyen“DevelopmentToolsfortheCalPolySuperProjectUsingthe
DigilentSpartan3EFPAGBoard.”CalPolySeniorProject,Spring2009
22
VIII. Appendix
A.MUX.h–MUXControlAlgorithmHeaderFile
/**************************************FrankScarfo*CalPolySuPERProject*AnalogMUXcontrolsampleproject*File:mux.h*************************************/#include<xio.h>#include<xparameters.h>#ifndefMUX_H#defineMUX_H#define MUX (*(volatileunsignedlong*)(XPAR_MUX_BASEADDR+0x00))#define MUX_DD (*(volatileunsignedlong*)(XPAR_MUX_BASEADDR+0x04))#define SENSOR_MASK0x0F;voidinitMUX();intnextSensor();#endif
B.MUX.c–MUXControlAlgorithmSourceCode
/**************************************FrankScarfo*CalPolySuPERProject*AnalogMUXcontrolsampleproject*File:mux.c*************************************/#include"mux.h"longsel;/*Setselectlinedatadirectiontooutandinitializevariables*/voidinitMUX(){ MUX_DD=0x00; sel=‐1;}/*Iteratetonextsensors*/intnextSensor(){ sel=(sel+1)&SENSOR_MASK; MUX=sel; returnsel;}
23
C.Lcd.h–LCDControlHeaderFile
/****************************************lcd.h***************************************/#ifndefLCD_H#defineLCD_H/*RegisterSettings*/#define LCD (*(volatileunsignedlong*)(XPAR_LCD_BASEADDR+0x00))#define LCD_DD (*(volatileunsignedlong*)(XPAR_LCD_BASEADDR+0x04))#define LCD_DATA 0x0F#define LCD_E 0x10#define LCD_RS 0x20#define LCD_RW 0x40#define LCD_BUSY 0x80#define LCD_CMD 0x00#define LCD_CHAR LCD_RS/*FunctionPrototypes*/voidinitLcd();voidwriteLcd(intrs,intvalue);voidprintLcd(char*msg);voiddisplay_num(doublen);#endif
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D.LCD.c–LCDControlSourceCode
/******************************************lcd.c*****************************************/#include<xparameters.h>#include"lcd.h"intreadLcdStatus(){inti,r;/*SetLCDdatalinestoinputs*/LCD_DD=LCD_DATA; //Setdatalinestoinputs/*Firstreadcycle*/LCD=LCD_RW; LCD=LCD_RW|LCD_E;/*~125ns*/r=(LCD&LCD_DATA);/*~125ns(Ehighfor~250ns)*/for(i=0;i<5;++i)/*Wait~750ns*/LCD=LCD_RW;/*Secondreadcycle*/r<<=4;LCD=LCD_RW|LCD_E;/*~125ns*/r|=(LCD&LCD_DATA);/*~125ns(Ehighfor~250ns)*/for(i=0;i<5;++i)/*Wait~750ns*/LCD=LCD_RW;/*SetLCDbacktooutput*/LCD_DD=0; /*Sendbackstatusbyte*/returnr&0xFF;}voidsendLcd(intrs,intd){inti;/*Firstwritecycle*/LCD=rs; LCD=rs|LCD_E|d;/*~125ns*/LCD=rs|LCD_E|d;/*~125nstotalEhighfor~250ns*/LCD=rs|d; /*~125nsHoldtime*/for(i=0;i<5;++i)/*Wait~750ns*/LCD=rs;}voidreturnLcdHome(){/*SendcommandtoreturntheLCDcursortothehomeposition*/sendLcd(LCD_CMD,0x02);}voidwriteLcd(intrs,intvalue){inti,d;if(rs)
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rs=LCD_RS;/*WaitfortheLCDtonotbebusy*/while(readLcdStatus()&LCD_BUSY);/*Senduppernibble*/sendLcd(rs,(value>>4)&LCD_DATA);/*Sendlowernibble*/sendLcd(rs,value&LCD_DATA);for(i=0;i<10;++i)LCD=0;/*Wait~1000ns*/} voidinitLcd(){inti;/*SetLCDdatalinestooutputs*/LCD_DD=0;for(i=0;i<20*5500;++i)LCD=0;/*~20msdelay*//*Setto8‐bitoperation*/sendLcd(LCD_CMD,0x03);for(i=0;i<500;++i)LCD=0;/*~91usdelay*//*Setto8‐bitoperation*/sendLcd(LCD_CMD,0x03);for(i=0;i<500;++i)LCD=0;/*~91usdelay*//*Setto8‐bitoperation*/sendLcd(LCD_CMD,0x03);for(i=0;i<500;++i)LCD=0;/*~91usdelay*//*Setto4‐bitoperation*/sendLcd(LCD_CMD,0x02);for(i=0;i<500;++i)LCD=0;/*~91usdelay*//*FunctionSet*/writeLcd(LCD_CMD,0x28);/*DisplayOn*/writeLcd(LCD_CMD,0x0C);/*ClearScreen*/writeLcd(LCD_CMD,0x01);/*SetEntryMode*/writeLcd(LCD_CMD,0x06);}voidprintLcd(char*msg){/*WriteoutthemessageacharacteratatimeuntilmsgpointstoNULL*/while(*msg)writeLcd(LCD_CHAR,*(msg++));}/*display_num:displaysthegivennumberupto*7digitsontheLCD*/voiddisplay_num(doublen)
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{inti;/*Writeoutnegativesignifneeded*/if(n<0){writeLcd(LCD_CHAR,'‐');n*=‐1;}/*Converteachdigitforupto7digitsintoacharactertooutput*/unsignedcharmillions=((int)n/1000000)+48;unsignedcharhun_thousands=(((int)n%1000000)/100000)+48;unsignedcharten_thousands=(((int)n%100000)/10000)+48;unsignedcharthousands=(((int)n%10000)/1000)+48;unsignedcharhundreds=(((int)n%1000)/100)+48;unsignedchartens=(((int)n%100)/10)+48;unsignedcharones=((int)n%10)+48;unsignedchartenths;unsignedcharhundredths;/*Calculatethedecimalremainderbysubtractingtheotherplacesfromtheinputtednumber*/doubledecimal=n‐(millions‐48)‐(hun_thousands‐48)‐(ten_thousands‐48)‐(thousands‐48)‐(hundreds‐48)‐(ones‐48);/*Ifadecicalportionexists,calculatethetenthsandhundredthsvalues*/if(decimal>0){tenths=(int)(decimal*10)+48;hundredths=((int)(decimal*100)%10)+48;}/*Writeoutthemillionsdigitif>0*/if(n>=1000000)writeLcd(LCD_CHAR,millions);/*Writeoutthehundredthousandsdigitif>0*/if(n>=100000)writeLcd(LCD_CHAR,hun_thousands);/*Writeoutthetenthousandsdigitif>0*/if(n>=10000)writeLcd(LCD_CHAR,ten_thousands);/*Writeoutthethousandsdigitif>0*/if(n>=1000)writeLcd(LCD_CHAR,thousands);/*Writeoutthehundredsdigitif>0*/if(n>=100)writeLcd(LCD_CHAR,hundreds);/*Writeoutthetensdigit>0*/if(n>=10)writeLcd(LCD_CHAR,tens);/*Writeouttheonesdigit*/writeLcd(LCD_CHAR,ones);/*Checkifthere'sadecimalandthat
27
itismadeupofvalidnumbercharacters*/if(decimal>0&&tenths>47&&tenths<58){/*Writeoutthedecimaltothe hundredthsplace*/writeLcd(LCD_CHAR,'.');writeLcd(LCD_CHAR,tenths);writeLcd(LCD_CHAR,hundredths);}}
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E.Timer.h–TimerControlHeaderFile
/**********************************timer.h*********************************/#ifndefTIMER_H#defineTIMER_H#define TCSR0 (*(volatileunsignedlong*)(XPAR_TIMER_BASEADDR+0x00))#define TLR0 (*(volatileunsignedlong*)(XPAR_TIMER_BASEADDR+0x04))#define TCR0 (*(volatileunsignedlong*)(XPAR_TIMER_BASEADDR+0x08))#define TCSR1 (*(volatileunsignedlong*)(XPAR_TIMER_BASEADDR+0x10))#define TLR1 (*(volatileunsignedlong*)(XPAR_TIMER_BASEADDR+0x14))#define TCR1 (*(volatileunsignedlong*)(XPAR_TIMER_BASEADDR+0x18))voidtimerISR(void);voidinitTimer(unsignedintcount,intset_interrupt);#endif
F.Timer.c–TimerControlSourceCode
/********************************timer.c*******************************/#include<xparameters.h>#include"timer.h"//#include"intc.h"//#include"leds.h"//#include"mux.h"voidinitTimer(unsignedintcount,intset_interrupt){ TLR0=count; //SetloadRegister TCSR0=0x072; //Turnontimerwithloadbit TCSR0=0x0D2; //Clearloadbit //if(set_interrupt) // SIE=XPAR_TIMER_INTERRUPT_MASK; //EnableInterruptinIntc}voidtimerISR(void){ //LEDS=nextSensor(); TCSR0=TCSR0;}
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G.Leds.h–LEDControlHeaderFile
/******************************leds.h*****************************/#ifndefLEDS_H#defineLEDS_H#define LEDS (*(volatileunsignedlong*)(XPAR_LEDS_BASEADDR+0x00))#define LEDS_DD (*(volatileunsignedlong*)(XPAR_LEDS_BASEADDR+0x04))#define initLeds(){LEDS_DD=0x00;}#endif
H.main.c–SampleControlAlgorithmSourceCode
/**************************************FrankScarfo*CalPolySuPERProject*AnalogMUXcontrolsampleproject*File:main.c*************************************/#include<xio.h>#include<xparameters.h>#include"spi.h"#include"lcd.h"//#include"intc.h"#include"timer.h"#include"leds.h"#include"mux.h"#defineclock50000000#definefrequency20#defineclk_load(clock/(frequency*100))intdutycycle;longticks;longrecalc;doubleinput[64];longdataStart;voidmainISR()__attribute__((interrupt_handler));voidrecalcOutputs(){ inti; for(i=dataStart;i<dataStart+32;i++){ if(input[i]>1.8) dutycycle+=1; elseif(input[i]<1.5) dutycycle‐=1; }}
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voidmainISR(){ /*AdjustPWMSignal*/ if(ticks<=(clk_load*dutycycle/10000)) LEDS|=0x80; elseLEDS&=0x0F; if(ticks>=clk_load/100) ticks=‐1; if(recalc>=frequency*100){ recalcOutputs(); recalc=0; dataStart=(dataStart+32)%64; } ticks++; recalc++; timerISR();//ResetTimer}intmain(){ inti,j,sel; unsignedintadc[2]={0x00,0x00}; doublein; /*InitializeAddDevices*/ initSPI(); clearSPI(); initLcd(); initLeds(); initMUX(); initTimer(clk_load,1); for(i=0;i<64;i++){ input[i]=1.7; } /*Initializeallvariables*/ ticks=0; recalc=0; dutycycle=50; dataStart=0; /*TurnOnInterrupts*/ microblaze_enable_interrupts(); for(;;) { /*Changeselectlinestonextinput*/ sel=nextSensor(); LEDS=sel; /*SetAmplifierValues*/ SPICR=0x08E; sendAmp(x2,x5);
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SPICR=0x086; readADC(adc); SPICR=0x08E; sendAmp(x2,x5); SPICR=0x086; readADC(adc); SPICR=0x08E; sendAmp(x2,x5); SPICR=0x086; readADC(adc); /*GetADC1Value,Storeintoarray,andprinttoLCD*/ writeLcd(LCD_CMD,0x01); printLcd("S"); display_num(2.0*sel); printLcd(":"); in=getAdcVoltage(twosComplement(adc[0],14),0x2); input[2*sel+dataStart]=in; display_num(in); printLcd("v("); display_num(twosComplement(adc[0],14)); printLcd(")"); /*GetADC2Value,Storeintoarray,andprinttoLCD*/ writeLcd(LCD_CMD,0xC0); printLcd("S"); display_num(2.0*sel+1); printLcd(":"); printLcd(":"); in=getAdcVoltage(twosComplement(adc[1],14),0x2); input[2*sel+1+dataStart]=in; display_num(in); printLcd("v("); display_num(twosComplement(adc[1],14)); printLcd(")"); /*Delay‐Uncommentfordemopurposes*/ //for(j=0;j<1000000000;j++); }return0;}
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I.spi.h–SPIControlHeaderFile
/********************************************spi.h*******************************************/#ifndefSPI_H#defineSPI_H/*Amplifiergainsettings(allvaluesarenegative!)*/#definex1 0x01#definex2 0x02#definex5 0x03#definex10 0x04#definex20 0x05#definex50 0x06#definex100 0x07/*Registersettings*///#defineFLASH_ADC_SEL_DD(*(volatileunsignedlong*)(XPAR_FLASH_ADC_SEL_BASEADDR+0x04))//#defineFLASH_ADC_SEL (*(volatileunsignedlong*)(XPAR_FLASH_ADC_SEL_BASEADDR+0x00))#defineAD_CONV_DD (*(volatileunsignedlong*)(XPAR_AD_CONV_BASEADDR+0x04))#defineAD_CONV (*(volatileunsignedlong*)(XPAR_AD_CONV_BASEADDR+0x00))#define SPICR (*(volatileunsignedlong*)(XPAR_SPI_BASEADDR+0x60))#define SPISR (*(volatileunsignedlong*)(XPAR_SPI_BASEADDR+0x64))#define SPIDTR (*(volatileunsignedlong*)(XPAR_SPI_BASEADDR+0x68))#define SPIDRR (*(volatileunsignedlong*)(XPAR_SPI_BASEADDR+0x6C))#define SPISSR (*(volatileunsignedlong*)(XPAR_SPI_BASEADDR+0x70))#define SPIGIE (*(volatileunsignedlong*)(XPAR_SPI_BASEADDR+0x1C))#define SPIISR (*(volatileunsignedlong*)(XPAR_SPI_BASEADDR+0x20))#define SPIIER (*(volatileunsignedlong*)(XPAR_SPI_BASEADDR+0x28))#define SPIRXF (*(volatileunsignedlong*)(XPAR_SPI_BASEADDR+0x78))/*Definedconstantsandmacros*/#define SPI_DAC 0x01#define SPI_AMP 0x02#define SPI_ADC 0x04#defineDAC_A0x00#defineDAC_B0x01#defineDAC_C0x02#defineDAC_D0x03#defineDAC_ALL0x0F#define sendDAC(n,val) writeSPI(SPI_DAC,0x00300000|(((n)&0x0F)<<16)|(((val)&0x0FFF)<<4),4)#define sendAmp(a,b) writeSPI(SPI_AMP,(((b)&0x07)<<4)|((a)&0x07),1)/*Functionprototypes*/voidinitSPI(void);voidclearSPI(void);intreadSPI(unsignedintnumBytes);voidwriteSPI(unsignedintdevice,unsignedintvalue,unsignedintnumBytes);voidreadADC(unsignedintadc[]);doublegetAdcVoltage(doubleadc_val,intgain);#endif
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J.spi.c‐SPIControlSourceCode
/***********************************spi.c**********************************/#include<xparameters.h>#include<stdio.h>#include<stdlib.h>#include<string.h>#include"spi.h"//#include"intc.h"#include"lcd.h"staticunsignedintdeviceMask;inttwosComplement(unsignedintnum,intn){intnum_2s=0;inti;/*Functiononlyworksupto32bits.Return0ifnis>32*/if(n>32)return0;/*IftheMSBofthenumberisaonethenperformtwo'scomplementandnegatevalue*/elseif(num&(0x1<<(n‐1))){/*Takethecomplementofthenumber andadd1togetthetwo'scomplement value*/num_2s=~num+1;/*Zeroouttheupperbitsfromthe nthtothe32ndbit*/for(i=n;i<32;i++) num_2s&=~(0x1<<i);/*IftheMSBofthenumberisaone thennegatethetwo'scomplement value*/if(num&(0x1<<(n‐1))) num_2s*=‐1;}/*Positivenumber,whichisthesameasthetwo'scomplementequivalent*/elsenum_2s=num;returnnum_2s;}voidinitSPI(void){/*Setallsalveselectlineshigh*/SPISSR=~0;/*SetupSPIcontrolregister*/SPICR=0x086;
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/*EnableSPIinterrupts*/SPIGIE=~0;/*Setupdevicemask,whichisthestatuswhenalltheSSlinesarehigh*/deviceMask=SPISSR;/*EnabletheinterruptinIntc*//*SIE=XPAR_OPB_SPI_0_IP2INTC_IRPT_MASK;*/}voidclearSPI(void){/*Waitforthelasttransactiontofinish*/while(SPISSR!=deviceMask);/*Setthe"TxFIFOReset"and"RxFIFOReset"Bits*/SPICR|=0x60;/*Clearthe"TxFIFOReset"and"RxFIFOReset"Bits*/SPICR&=~0x60;}voidreadADC(unsignedintadc[]){unsignedintvalue=0x00;/*ChangetheSPIcontrolregisterclockphase(CPHA)bitto'1'tochangethephasefortheADC*/SPICR=0x08E;/*ManuallytriggertheAD_CONVsignaltobeginreadingindatatotheADC*/AD_CONV_DD=0x0;AD_CONV=0x0;/*Waitforthelasttransactiontofinish.Allowsdatatobeconverted.*/while(SPISSR!=deviceMask); /*ManuallytriggertheAD_CONVsignalagaintobeginoutputofconverteddata*/AD_CONV=0x1;AD_CONV=0x0;/*ReadinvaluesfromtheADC,seperatethetwoADCAandBvaluesandstorethemintoanarray*/value=readSPI(4);adc[0]=((value>>16)&0x00003FFF);adc[1]=((value)&0x00003FFF);/*ResettheclockphasefortheSPIbusincaseanotherdeviceisbeingused,suchastheDAC*/SPICR=0x086;}intreadSPI(unsignedintnumBytes){intvalue=0;/*Forcethemaximumsendwidthtobe
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fourbytes*/if(numBytes>4)numBytes=4;/*Waitforthelasttransactiontofinish*/while(SPISSR!=deviceMask);/*ReadineachbytefromtheRxFIFO*/for(;numBytes;‐‐numBytes) /*AppendthecurrentbytetotheLSBofthevalue*/value=(value<<8)|(SPIDRR&0x0FF);/*ReturnthefinalvaluereadinfromtheSPI*/returnvalue;}voidwriteSPI(unsignedintdevice,unsignedintvalue,unsignedintnumBytes){inti;/*Forcethemaximumsendwidthtobefourbytes*/if(numBytes>4)numBytes=4;/*Waitforthelasttransactiontofinish*/while(SPISSR!=deviceMask);/*LowertheSSlineforthespecifieddevice*/SPISSR&=~device;/*Specialcaseforwritingtotheamplifiers*/if(device==SPI_AMP){/*SendthesamebytetotheTxFIFOfourtimes toensuretheampsgetthenewsettings*/for(i=0;i<4;i++) SPIDTR=value;}/*Othercases*/else{/*PutthebytesofthedataintotheTxFIFO MSBfirst*/for(;numBytes;‐‐numBytes) { SPIDTR=(value>>((numBytes‐1)*8))&0xFF; }}/*WaitfordataintheTxFIFOtobetransmittedbypollingthestatusbit*/for(;;){if(SPISR&0x04) break;}/*RaisetheSSlineswhenfinished*/SPISSR=~0;}
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doublegetAdcVoltage(doubleadc_val,intgain){doublevin;/*BasedontheUser'sGuideontheADC(p.76)*/doubledivisor=8192.0;/*SetthedivisorforcalculatingtheADCvoltagebasedonthegivengainsetting*/switch(gain){case0x1:divisor*=‐1.0;break;case0x2:divisor*=‐2.0;break;case0x3:divisor*=‐5.0;break;case0x4:divisor*=‐10.0;break;case0x5:divisor*=‐20.0;break;case0x6:divisor*=‐50.0;break;case0x7:divisor*=‐100.0;break;default:break;}/*CalculateADCinputvoltagebasedontheformulaintheUser'sGuide(p.76)*/vin=((adc_val/divisor)*1.25)+1.65;/*Sendinputvoltagevalueback*/returnvin;}
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L.AnalysisofSeniorProjectDesign
SummaryofFunctionalRequirements
ThisprojectimplementsananalogmultiplexertointerfaceaSpartan3eFPGAboardtotheCalPolySustainablePowerforElectricalResources(SuPER)project.Itincludessoftwaretocontrolthemultiplexeraswellasasamplecontrolalgorithmtodemonstratethecapabilitiesofthesystem.
PrimaryConstraints
TheSuPERproject’ssuccessisbasedontwomainconstraints,lowcostsandefficientuseofpower.Myprojectaidsingreatlyimprovingbothofthesecrucialareas.
Economic
WhilemyprojectcostfairlylittletoimplementitwillhaveaprofoundeffectontheunderdevelopedregionsaspartoftheSuPERproject.Byprovidingthesepeoplewithpowertoperformeverydaytasks,weenablethemtospendlesstimeongatheringtheirbasicneeds,allowingthemtoparticipateinmoreusefuleconomicactivity.
Commercial
Currently,theSuPERprojectisseveralyearsawayfrombeingviableforcommercialmarkets.Therestillneedstobeextensivetestingandimprovementstovarioussystemsbeforethiscanbefullyconsidered.
Environmental
TheSuPERprojectwillprovideextensiveimprovementsinthepushforrenewableenergy.Sustainablepowersuchassolarlowersthedemandforharmfulresourcessuchasoil.
Sustainability
Withsustainabilityasoneoftheprojectscoregoals,itwillprovideoneofthemostefficientsourcesofcleanenergy.Oursystemwillbeabletoprovidepowerforseveraldecadespoweredonlybysolarenergy.
HealthandSafety
Thisprojectwillonlyopenupmoreopportunitiesforpeopleinunderdevelopedareastolivehealthiersaferlives.Peoplewillbeabletousethe