RaspberryPIUsersGuide

Copyright2014Vilros.Allrightsreserved.www.vilros.com1-855-207-9254ISBN:978-0-692-31936-9

Nopartofthispublicationmaybereproduced,distributed,ortransmittedinanyformorbyanymeans,includingphotocopying,recording,orotherelectronicormechanicalmethods,withoutthepriorwrittenpermissionofthepublisher,exceptinthecaseofbriefquotationsembodiedincriticalreviewsandcertainothernon-commercialusespermittedbycopyrightlaw.

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ConventionsUsedinthisBook

Thefollowingtabledescribesthetextconventionsusedinthisbook.ConventionMeaning

ItalicTextthatappearsinitalicsreferstofilenames,variableandfunctionnames,orothercode.Withinthecontextofgivinginstruction,italictextshouldbetypedexactlyasshown.

BoldWithinthecontextofgivinginstruction,itemsinboldtextareuserinterfaceelements,suchaskeystrokes,menuitems,orbuttonlabels.

MonospacefontAmonospacefontisusedforshellcommandsandPythoncodethatshouldbetypedinonthekeyboard.

Contents1GettingStarted51.1Introduction51.2TechnicalSpecifications71.3BasicSetup81.4SDCards14

2IntroducingRaspbian162.1RaspbianandLinux162.2InstallationofRaspbianwithNOOBS162.3InstallationofRaspbianusingaDiskImage202.4Raspi-config222.5RaspbiansDesktopEnvironment262.6CommonTasks372.7NetworkConnectionsandRemoteAccess402.8OtherOperatingSystems45

3BuildingaMediaCenterwithXBMC473.1XBMC473.2Installation483.3FirstSteps513.4MediaFilesandtheLibrary533.5NetworkDevicesandOtherComputers593.6Add-ons653.7RemoteControls66

4ProgrammingwithScratch694.1TheUserInterface694.2Sprites754.3ArithmeticandVariables814.4Decisions824.5Loops854.6Strings864.7Messages874.8SoundandMusic894.9ThePaintEditor894.10AutomaticStartupofScratchProjects934.11SharingYourFinishedProjects94

5BuildinganArcadeGameinScratch955.1TheTitleScreen955.2TheLevelBackgrounds995.3ThePlayerSprite1055.4CollisionDetection1095.5Enemies1155.6MoreEnemies1275.7GameOver128

6ProgramminginPython1296.1YourFirstPythonProgram1296.2Python1316.3Decisions1366.4Loops1386.5Functions1396.6ClassesandObjects1416.7ModulesandPackages1446.8FileI/O1466.9GraphicalUserInterfaces(GUIs)149

7ControllingInputandOutputPins1507.1ElectronicCircuits,VoltageandCurrent1507.2SolderlessBreadboards1527.3TheGPIOHeader1537.4BasicOutput1557.5BasicInput1607.6Communicationbetween3.3Vand5VDevices1647.7SerialPeripheralInterface(SPI)1667.8I2CCommunication1717.9SerialUARTs173

8BuildinganIPCamera1768.1ThePiCameraModule1768.2Motion178

9BuildingaSmarterDoorbell1849.1TheButtonCircuit1849.2Speakers1859.3ABasicDoorbell1869.4AnEnhancedDoorbell188

10MakingFreePhoneCallswithGoogleVoice19010.1SIPandSoftphones19010.2GoogleVoice19210.3RasPBX19310.4SIPPhonesacrosstheInternet198

11Accessories199

1GettingStarted

1.1Introduction

TheRaspberryPiisasmallcomputer,averysmallcomputer.

Itconsistsofmostlythesamepartsasastandarddesktopcomputerorlaptop.Acentralprocessingunit(CPU)actsasabrain,randomaccessmemory(RAM)andlong-termstoragedevicesareusedtoholddata,avideodisplayshowsyouwhatishappening,andyouinteractwithallofthisusingmice,keyboards,joysticks,andotheruniversalserialbus(USB)devices.ThePimaybelesspowerfulthanyourWindowsPCorMacintosh,butitisstillimpressivethatitfitsallofthisonaboardonlyslightlylargerthanacreditcard.

TheoriginalgoaloftheUK-basedRaspberryPiFoundationwastocreateadevicethatwouldaddresstheirperceptionoffallingstandardsintheteachingofcomputerscience.Ascomputershaveevolved,theyhavebecomemoredifficulttowritesoftwareforatalow-levelwithcloseinteractionbetweenhardwareandsoftware.Andastheyhavebecomemoreintegratedinourdailylives,theconsequencesofbreakingyourcomputerbyexperimentinghavebecomemoresevereandexpensive.

So,unlikeconventionalsystems,thePiisamachinethatisdesignedtobeplayedwithandusedforexperiments.Itsdiminutiveformfactorandrelativelylowcostmeanthatyoucandowhatyouwantwithit,andthisattractsfarmorediversegroupsofusersthanjuststudentsandteachers.

Itissuitableforawiderangeofapplications,including:

UsingthePiforGeneralComputingYoucaninstallavarietyofoperatingsystemsonthePi,andmanyofthesehavefulldesktopenvironments.Withsupportforexternalhardwaredevices,Internetconnections,anddownloadingandinstallingsoftware,youcanusetheRaspberryPiasaregularcomputer.Itcandojustabouteverythingyourmainsystemcandoonlyalittleslower.

PlayingGamesTherangeofgamesavailableontheRaspberryPisoperatingsystemsisextensive.Butyoucanalsoinstallemulators,whicharepiecesofsoftwarethatallowprogramsfromothermachinestoberunonthePi.ThisgivesyouaccesstotitlesonclassicmachinessuchastheAtari2600,NintendoEntertainmentSystem,SegaGenesis,SharpX1,MSX,Panasonic3DO,andmanymore.AllRaspberryPimodelssupportHDMIvideooutputandUSBgamecontrollers,makingthePiapopularchoiceforfansofretrocomputingandretrovideogames.

PlayingMovieFilesandMusiconYourTVPutthePiinacase,connectittoatelevisionusinganHDMIcable,andinstallXBMC.ThenyouhaveacapablemediacenterthatcanloadmoviefilesfromtheSDcard,USBharddrives,oracrossyourlocalnetwork.

ProvidingNetworkServicesAsasmall,standalonedevicethatconnectstotheInternetandlocalnetworks,theRaspberryPimakesanexcellentserver.Youcanuseittoservefilesandwebpages,answerdomainnamesystem(DNS)requests,sharehardwaredevices(forexample,printers)acrossanetwork,andalmostanythingelseyoumightneedaserverfor.

SettingupDevelopmentEnvironmentsThesimplenatureofthePi,anditssupportformanydifferentprogramminglanguages,makeitanidealsystemtousewhenlearninghowtoprogram.ThePicontainsanARMprocessor,andthesearepopularlyusedincellphones,tablets,gamesconsoles,andinthecomputer-controlledequipmentusedinmanufacturing.Theabilitytoprogramoneisaskillthatisinhighdemand.

BuildingControllerBoardsandInteractionwithElectronicsItssmallsize,lowcost,andeaseofprogrammingmaketheRaspberryPiveryusefulinembeddedapplications.Inthesetypesofproject,thePiisusedalongwithotherelectronicscircuitstocreateeverythingfrom3Dprinters,tohomeautomationsystemsandrobots.

1.2TechnicalSpecifications

TheModelB+isarevisedversionoftheModelBthatwilleventuallyreplacetheearliermodel.Ithasmoregeneralpurposeinput/output(GPIO)pinsthanearliermodels,andtwiceasmanyUSBsockets.ModelB+CPUBroadcommicroprocessorrunningat700MHz(ARMv6architecture)GPUBroadcomVideoCoreIV,250MHz

OpenGLES2.0MPEG-2andVC-1,1080ph.264/MPEG-4AVCdecoder

Memory512MBVideoOutputVideoOutputpole3.5mmjack,LCDpanelsthroughDSI.AudioOutput4-pole3.5mmjack,HDMI,I2SUSBPorts4(2dualsockets)Input/Output17xGPIO,UART,I2C,SPINetworking10/100Mb/sEthernet,USBdevicesStoragemicroSDcardslotPower5Vthroughmicro-USBsocketorGPIOheader

ThediagrambelowshowstheavailableconnectorsontheRaspberryPiModelB+.Figure1.TheRaspberryPianditsconnectors1Generalpurposeinput/output(GPIO)headerthesepinscanbecontrolledfromsoftware.

2Universalserialbus(USB)socketforattachingperipheraldevicessuchasmice,keyboards,ormemorysticks.ThisisadualsocketandtwoUSBdevicescanbeconnectedatthesametime.

310/100Mb/sEthernet(RJ45)socketforconnectingtoanetworkrouter.

44-pole3.5mmoutputjackforaudioandvideo.5Cameraserialinterface(CSI).6High-definitionmultimediainterface(HDMI)videooutput.7Powerinviamicro-USBsocket.

8Displayserialinterface(DSI)flexibleflatcableconnectorforliquidcrystaldisplays(LCDs).9microSDsocket.Thecardsocketisattachedtotheundersideoftheboard.

1.3BasicSetup

TostartusingyourPi,youneedtoconnectitto:1.Power

2.AnSDcardwithanoperatingsystemorbootableprograminstalledWithoutthese,thePiwilldonothing,notevenoutputavideosignal.Fortheinitialconfiguration,youmayalsoneedtoconnect:

1.Adisplay(usingHDMIorcompositevideo)2.AUSBkeyboard3.AnEthernetcableorUSBWi-Fidongle

Thedisplay,andanyUSBdevicesyoumayconnect,canberemovedwhentheyarenotinuse.Forexample,aPiactingasafile/printservermayonlyacceptinputfromcomputersonthenetworkanddoesnotalwaysneedakeyboardorscreen.

FittingaHeatSinkWhenthecomponentsinacomputersystemworkhard,theygenerateheat.Andaboveacertainlevel,thisheatcanreducethelifespanofthecomponentsorevenbreakthemaltogether.Aheatsinkisacarefullydesignedblockofmetalthattakestheheatawayfromtheelectroniccomponentandthenpassesitintotheairsurroundingthedevice.

TherearethreechipsonaRaspberryPithatcangetveryhotifthedeviceisworkinghard:thecentralprocessingunit(1),thechipthatcontrolstheEthernetandUSBports(2),andthepowerregulator(3).

Toinstallaheatsink:1.UnplugthePiandleaveittocoolbeforeattemptingtohandlethedevice.2.Onthebottomoftheheatsink,peelawaytheplasticbackingthatcoverstheadhesive.

3.Presstheheatsinkdownfirmlyanddirectlyontothechip.Holdthepressureforafewsecondstoallowtheadhesivetowork.

IfyoubuyheatsinksforyourPi,onlyusethethermaladhesivethattheyarrivewith;neveruseanyothertypeofadhesiveorstickyplastictoinstallaheatsinkonaRaspberryPi.TheadhesivemustbeaspecialcompoundsothatiteffectivelytransfersheatfromthechiponthePitothemetaloftheheatsink.

Figure2.Thethreeheat-outpointsonaPi(left);andinstallingaheatsinkontheCPU(right)

ConnectingPowerTheRaspberryPirequiresapowersupplyof5Vthatcanprovideatleast700mAofcurrent.BeforeconnectingthePiandturningiton,youshouldchecktheratingofthepowersupplycarefully.

Manycellphonechargerswillwork,butsomesupplylesscurrentthanthePineeds.Usinginadequatepowersupplies,orevenpoweringthePifromtheUSBportofanothercomputer,isnotrecommendedasthelackofcurrentmaymakethePiunstable.YoushouldcertainlyavoiddoingthisifyouneedtoconnectanyotherdevicestothePi.

PowercanbefedintothePithroughthemicro-USBsocketor,ifyouhaveasuitable

connector,throughthegeneralpurposeinputoutputpins.However,youshouldbeawarethatprovidingpowerthroughtheGPIOheaderpinsbypassestheon-boardprotectioncircuitrythatisdesignedtopreventdamagetothedevice.Forthisreason,itshouldonlybeattemptedbypeoplewhoareexperiencedinbuildingelectroniccircuits.

ItisworthnotingthattheRaspberryPidoesnothaveanon/offswitch.Someoperatingsystemscanpowerdownthedeviceorputitintostandbymodebutwhenyouwanttoturnitoff,youwilloftenhavetoremovethepowersupplyorswitchitoffatthewallsocket.Therearetwoholesontheprintedcircuitboard(PCB)oftheModelB+.TheseholesarelabelledRUNandyoucansolderaswitchacrossthesetwoconnectionstocreatearesetbutton.

ConnectingaDisplayHDMIoffersahigh-qualityvideoandaudiosignal,andisthepreferredwayofconnectingallmodelsofRaspberryPitoamoderntelevision.Toconnectahigh-definitiontelevision:

PlugoneendofanHDMIcableintotheRaspberryPisHDMIsocket,andtheotherendintoanHDMIinputonyourTV.

IfyourdisplaydoesnotsupportHDMI,youcanconnectthecompositevideoandaudiooutputstotheauxiliaryA/Vinputofmosttelevisions.Theseconnectionsarecoloredyellow,red,andmosttelevisions.Theseconnectionsarecoloredyellow,red,andpolejackononeend,andthreeRCAplugsontheother(oneyellow,onered,andonewhite).Tousethesecables:

1.Plugthe4-pole3.5mmjackplugintothe3.5mmjacksocketontheRaspberryPiModelB+.2.ConnecttheyellowcompositevideoplugtotheyellowvideoinputsocketonyourTV.3.ConnecttheredRCAplugtotheredaudiosocketonyourTV.4.ConnectthewhiteRCAplugtothewhiteaudiosocketonyourTV.

IfyourTVdoesnothavetheyellow,red,andwhiteauxiliaryinputs,youcanplugthecompositeoutputsintoaSCARTadapterandconnectthattoyourTVinstead.

Whenusingthecompositevideo,youalwayshavetheoptionofconnectingthevideotoatelevisionandtheaudiooutput(theredandwhiteconnectors)tootherdevices,suchasheadphones,poweredspeakers,oramplifiers.

TouseacomputermonitorasthePisdisplay,youwillneedanHDMItoVGA,orHDMItoDVIadaptor.However,whenconnectingtoamonitorusinganHDMItoVGA/DVIadapter,youwillinitiallybeunabletoconnectspeakerstotheaudioconnector.WhentheHDMIcableisconnected,thecompositevideoandaudiooutputportsareturnedoff.ThiscanbechangedonceyouhaveanoperatingsystemrunningonthePi.Althoughnotcoveredinthisbook,allRaspberryPimodelssupportDSIforconnectingLCDpanels.Figure3.ConnectingadisplaytotheModelB+

ConnectingUSBDevicesWithmostoperatingsystemsthatyourunonthePi,humaninterfacedevices(HIDs)thatconnectusingUSB(suchasmice,keyboards,andgamecontrollers),andstoragedevices(suchasUSBmemorysticksandharddrives)willworkwithoutanyproblemsorinstallationprocesses.Youmayneedtoinstalldriverspiecesofsoftwarewrittentopassmessagesbetweentheoperatingsystemandthehardwaredevicetousemore

complicatedperipheralslikesoundcards.

ToconnectaUSBdevice,insertitsUSBconnectorintoanavailablesocketontheRaspberryPi.YoucanusuallydothissafelywhetherornotthePiisturnedonandrunning.

TheRaspberryPicanonlysupplyalimitedamountofpowertoUSBdevices.Itisrecommendedthatyoudonotconnectanydevicesthatdrawover100mA.Tousemorepower-hungrydevices,youcanuseapoweredUSBhubadevicethatallowsmultipleUSBperipheralstobeconnectedtoasingleport,andthathasitsownpowersupply.ThisalsoallowsyouattachmoredevicestothePi.Figure4.ConnectingthePitoa4-portUSBhub

ConnectingtoaNetworkTomakeawirednetworkconnectionbetweenthePiandanetworkrouter:

1.PlugoneendofaCAT5orCAT6EthernetcablewithRJ45connectorsintotheEthernetsocketontheRaspberryPi.

2.Plugtheotherendofthecableintoyournetworkrouter.TheactualnetworkconnectionismadebythesoftwareoroperatingsystemrunningonthePi.

Intheory,Wi-Fiisafastertechnologythanthe10/100Mb/sEthernetcircuitthatisbuilt-intoModelB+.Inpractice,however,thisisnotalwaysthecase.AsthePicannotprocessdataasquicklyasabrandnewdesktopcomputer,thedifferenceinspeedbetweenEthernetandWi-Fiislessnoticeableandyoushouldusewhicheverismostconvenientforyou.NotallWi-FiandEthernetadaptorsarecompatiblewiththeRaspberryPi.Beforebuying,checkthattheadaptorisknowntobeworkingbylookingatthelistathttp://elinux.org/RPi_USB_Wi-Fi_Adapters

1.4SDCards

Inthenextchapter,youwilllearnaboutRaspberryPioperatingsystems(inparticularly,RaspbianLinux)andhowtoinstallthemontoanSDcard.Thiswillcompletetheset-upofthePi.

Unlikeconventionaldesktopcomputersystems,thePidoesnothaveaharddrivefromwhichtoloadanoperatingsystem.Instead,itusesthecardsockettoloadfilesfromamemorycard.

WhenthePiisfirstturnedon:1.ThemainARMprocessorandSDRAM(memory)aredisabled.

2.Thegraphicsprocessingunit(GPU)loadsthefirststagebootloaderthatisbuilt-intothePi,andthiscontainsallofthecodenecessarytoworkwithmemorycards.

3.Thefirst-stagebootloaderenablesSDRAM,detectsthepresenceofamemorycard,andloadsthesecond-stagebootloaderfromit.

4.Thesecond-stagebootloaderloadstheoperatingsystemorbootableprogramfromthecard.

InsertingandRemovingSDCardsItislikelythatyouwillneedamemorycardwithatleast4GBcapacityifyouareintendingtorunanoperatingsystemonthePi.4GBSDHCmicroSDcardsarewidelyavailableandgenerallyverycost-effective.

ToinsertanSDcard:1.EnsurethePiisunplugged.2.LocatetheSDcardsocketontheundersideofthePisboard.3.Whenlookingfromabove,theSDcardscontactsshouldbefacingup.4.Gently,butfirmly,pushtheSDcardintothesocketuntilitclicksintoplace.Figure5.InsertingSDcardsintotheRaspberryPiToremovetheSDcard:FirstpushthemicroSDfurtherintothedeviceuntilitclicks.Thenpullthecardout.

WheninsertingandremovingSDcardsinothercomputers,itisnotalwaysnecessarytoturnoffthedevice.However,asthememorycardcontainsitsoperatingsystem,thePimayaccessitatanytime.RemovingthecardwhilethePiisaccessingitcancorruptdataand,inextremecases,maystopthecardworkingatall.

2IntroducingRaspbian

2.1RaspbianandLinux

Anoperatingsystem(OS)isauniquetypeofapplicationthatyourunonyourcomputer.Itisanenvironmentinwhichmanyotherapplicationscanrunatthesametime,withaconsistentuserinterfaceandsharingthesameresources.MicrosoftWindowsandApplesMacOSXareprobablythetwomostwell-knownoperatingsystems,butthereareothers.

Linuxisoneofasmallgroupofoperatingsystemsthatarefree.ItusuallydoesntcostanythingtouseandpeoplecanmodifytheOS,repackageitwithothersoftware,distributetheirversion,andgenerallydowhattheywantwithit.Becauseofthis,youcanfindLinuxrunningonmosttypesofcomputerfromlargeserversusedbycorporationssuchasGoogle,tosmalldevicesliketheRaspberryPi.AbundleoftheLinuxcorewithotherapplications(suchasdesktopenvironments,filemanagers,andwebbrowsers)iscalledadistribution(ordistro).

RaspbianisaLinuxdistributionthatisbasedonDebian,anotherpopularversionofLinux.ItisdesignedfortheRaspberryPiandistheOSrecommendedbytheRaspberryPiFoundation.AlthoughdifferentLinuxdistributionscanusuallyallrunthesameapplications,thisbookisfocusedonusingRaspbiananditmaybehelpfulforyoutorunthisOSwhileyouarelearning.OnceyouarefamiliarwithRaspbian,youwillfindthatyouareabletouseothervarietiesofLinuxwithoutmuchhelp.

2.2InstallationofRaspbianwithNOOBS

NewoutofBoxSoftware(NOOBS)isatoolthatyoucanrunonyourRaspberryPianditwillhelpyouinstallanOS.ItstaysontheSDcard,evenaftertheOSinstalled,andcanalsobeusedtoeditthePismainconfigurationfileorreplacetheinstalledOSifproblemsoccur.TheSDcardsuppliedwithyourPialreadycontainsNOOBS.

InstallingNOOBStoanSDCardTherearetwoversionsofNOOBSavailable:NOOBSandNOOBSLite.NOOBSLiteisquickertodownload,butdoesnotcomewiththeinstallationfilesforRaspbian.Instead,yourPiconnectstotheInternettodownloadtherelevantfileswhenyoustarttheinstallationprocess.ItdoesnotsupportUSBWi-Fiadapters,andthismeansthatyouwillneedanEthernetcablepluggedintoyourRaspberryPitouseNOOBSLite.

ThefullversionofthelatestversionofNOOBSonlycomeswiththefilesneededtoinstallRaspbian.ToinstalladifferentOS,youneedanInternetconnection.

ThespacethatNOOBSoccupiesontheSDcardisnotavailableforusebytheOSthatyouareinstalling.Evena4GBSDcardwillsometimesnotbelargeenoughtoholdNOOBSandanOS,andstillhaveadequatespaceforyourfilesandprograms.

IfyoucannotuseNOOBS,youcaninstallanOSdiskimagetoyourSDcard.Thisisdescribedinsection2.3InstallationofRaspbianusingaDiskImageonpage20.

TheprocessforinstallingNOOBStoanSDcardisthesamewhetheryouareusingthefullNOOBSpackage,orNOOBSLite.OnWindows(8/7/Vista/XP):1.InserttheSDcardintoasuitablecardsocketorUSBcardreader.2.PresstheWindowslogokey+R.TypeexplorerandpressEnter.

3.IntheWindowsFileExplorerwindow,right-clickthecarddevice(usuallylabelledSDHCorRemovableDisk)andthenclickFormat.

4.IntheFilesystemlist,clickFAT32.5.IntheAllocationunitsizelist,clickDefaultallocationsize.

6.ClickStart.7.DownloadoneoftheNOOBSpackagesfromhttp://www.raspberrypi.org/downloads/

8.Findthe.zipfileyoudownloadedandright-clickit.PointtoOpenwithandthenclickWindowsExplorer.

9.PressCtrl+A,toselectallofthefilesinthe.ziparchive.10.PressCtrl+C,tocopytheselectedfilesintomemory.11.IntheWindowsFileExplorerwindow,right-clickthecarddevice.12.ClickPastetocopythefilestotheSDcard.13.IntheWindowsFileExplorerwindow,right-clickthecarddevice.

14.ClickEject.OnMacOSX:

1.InserttheSDcardintoasuitablecardsocketorUSBcardreader.

2.Onthedock,clickFinder.

3.Onthesidebar,clickApplications.4.ClickUtilities,andthendouble-clickDiskUtility.

5.Intheleftpanel,clicktheSDcard(usuallylabelledNONAMEifthecardwasnotformattedwithavolumename).

6.OntheErasetab,fromtheVolumeFormatlist,clickMS-DOSFileSystem.7.ClickErase.8.DownloadoneoftheNOOBSpackagesfromhttp://www.raspberrypi.org/downloads/9.InFinder,locatethe.zipfileyoudownloaded.

10.Double-clicktheNOOBSzipfileanditwillunziptoanewfolder.Forexample,afoldernamedNOOBS_lite_v1_3_9.1

11.Double-clickthefoldertoopenit.12.PressCmd+Atoselectallofthefiles.13.PressCmd+Ctocopythefilesintomemory.

14.Intheleftpanel,clicktheSDcard(usuallylabelledNONAMEifthecardwasnotformattedwithavolumename).

15.PressCmd+VtocopythefilestotheSDcard.16.Intheleftpanel,clicktheEjecticonnexttothenameoftheSDcard.

InstallingRaspbianToinstallRaspbian,youwillneedtoconnectakeyboard,mouse,anddisplaytoyourPi.

First,ensurethePiiscompletelyoffandunplugged,andtheninserttheSDcardintothePiscardsocket.ReconnectthepowertoyourPi.ThePiwillstartandwillloadtheNOOBStool.Wheneverythingisready,youshouldseeawindowsimilartoFigure1.

Figure1.NOOBSonaRaspberryPiThewindowshowsalistoftheoperatingsystemsthatyoucaninstall.1.IfyouhavearchivingsoftwareinstalledonyourMac,theNOOBSfilemightopenwiththisinstead..ToinstallRaspbian:1.Inthelist,clicktheboxnexttoRaspbian.2.Onthetoolbar,clickInstall.

Whentheinstallationiscomplete,theRaspberryPirestartsandloadstheraspi-configtool.Thishelpsyoutochangecertainimportantsettings.Formoreinformation,seesection2.4Raspiconfigonpage22.IfyouputtheSDcardbackintoaWindowsPCthenthecardwillappeartohaveshrunkincapacity.Ifyouwanttowipethecard,youcanusethecommand-linetooldiskparttodestroythepartitionsandcreateanewprimarypartitionusingalloftheavailablespace.

2.3InstallationofRaspbianusingaDiskImage

Adiskimageisaspecialtypeoffileformakingacopyofstoragedevices,suchasfloppydisks,CDs,harddrives,andmemorycards.Itnotonlycontainsallofthefilesfromthedevice,italsostoresalloftheinformationnecessarytorecreatethesamefilestructureandphysicallayoutonanotherdevice.

ManyoperatingsystemsthathavealreadybeenmadetoworkontheRaspberryPiareavailablefordownloadasdiskimages.TowritetheimagetoanSDcard,youcanuseaWindowsPC,MacorLinuxcomputer.1

DownloadtheRaspbiandiskimagefromhttp://www.raspberrypi.org/downloads/itisa.ziparchivethatyouneedtounzipbeforeitcanbeused.

TounzipthefileonWindows(8/7/Vista/XP):

1.Findthe.zipfileyoudownloadedandright-clickit.PointtoOpenwithandthenclickWindowsExplorer.1.OnlyinstructionsforWindowsandMacOSXarecoveredinthisguide.

2.Clickthe.imgfile,andthenpressCtrl+C.3.Intheleftpanel,clickDesktop.4.PressCtrl+Vtocopythe.imgfiletoyourDesktop.

TounzipthefileonMacOSX:

1.Onthedock,clickFinder.2.Findthe.zipfileyoudownloaded.3.Double-clickthe.zipfiletounzipittoanewfolder.

UsersofWindowswillneedtodownloadandinstallWin32DiskImagerfromhttp://sourceforge.net/projects/win32diskimager/beforecontinuing.UsersofMacOSXshouldinstallApplePi-Bakerfromhttp://www.tweaking4all.com/hardware/raspberry-pi/macosx-apple-pi-baker/

TowritetheRaspbiandiskimagetoanSDcardonWindows(8/7/Vista/XP):1.InserttheSDcardintoasuitablecardsocketorUSBcardreader.

2.IfyouarerunningWindowsXP:ontheStartmenu,underagroupnamedImageWriter,clickWin32DiskImager.

3.IfyouarerunningalaterversionofWindows:ontheStartmenu,underagroupnamedImageWriter,right-clickWin32DiskImager.ThenclickRunasadministrator.YoumaybeaskedtoconfirmthisbyawindowtitledUserAccessControl.ClickYes.

4.InWin32DiskImager,underImageFile,clickthefoldericon.Intheleft-handsideoftheWindowtitledSelectadiskimage,clickDesktop,andthendouble-clickthe.imgfilethatyouunzipped.

5.UnderDevice,ensurethatthedrivelettershownmatchestheonethatisdisplayedinWindowsExplorernexttoyourSDcard.

6.ClickWrite.7.Whentheprocessiscomplete,clickExit.

8.PresstheWindowslogokey+R.TypeexplorerandpressEnter.

9.IntheWindowsFileExplorerwindow,right-clickthecarddevice(usuallylabelledSDHCorRemovableDisk)andthenclickEject.

OnMacOSX:1.InserttheSDcardintoasuitablecardsocketorUSBcardreader.

2.Onthedock,clickFinder.3.Onthesidebar,clickApplications.4.Intherightpanel,double-clickApplePi-Baker.

5.IfmultipleSDcardsarelistedunderPi-Crust:PossibleSD-Cards,clicktheoneyouwanttowriteto.

6.UnderPi-Ingredients:IMGRecipe,clickIMGtoSD-Card.7.Locatethe.imgfilethatyouunzipped,thenclickOpen.8.EntertheadministratorpasswordforyourMac.

9.Whentheprocessiscomplete,clicktheClosebutton.TheninFinder,clicktheEjectbuttonnexttotheSDcard.

EnsurethePiiscompletelyoff,andtheninserttheSDcardintothePismemorycardsocket.ReconnectthepowertoyourPi.

2.4Raspi-config

WhenRaspbianstartsforthefirsttime,itrunsatoolcalledraspiconfig.YoucanusethistochangeseveralconfigurationoptionsthataffecthowRaspbianoperates.Raspi-configisacommandlineapplicationandiscontrolledusingthekeyboard:UsetheUpandDownArrowkeystohighlightmenu

items.PressEntertoactivatethehighlighteditem.

PresstheTabkeytomovethehighlightdowntothetwooptionsatthebottomofthewindowandandthenusetheLeftandRightArrowkeystochoosebetweenthosetwooptions.

Tomovebacktothemainmenu,presstheTabkeyagain.Whenyouhavefinishededitingthesettings,highlighttheoptionandpressEnter.WhenRaspbiansgraphicaldesktopisrunning,youcanaccesstheraspi-configtoolatanytimebydouble-clickingLXTerminalonyourdesktop.ThenenterthefollowingcommandandpressEnter:sudoraspi-config

ExploringtheSettingsinRaspi-configThetablebelowsummarizestheoptionsavailablefromthemainmenuinraspi-config:MenuOptionDescriptionExpandFilesystemMakethefullcapacityoftheSDcardavailabletotheoperatingsystemifisnotalreadyavailable.ChangeUserPasswordChangethepasswordforthedefaultuser(pi).

EnableBoottoDesktop/ScratchRaspbiancanautomaticallyloaddifferentapplicationswhenitstarts.Thissettingchangesthat.

InternationalisationOptionsConfigurelanguage,keyboardandculturesettings(suchasdateformatandtimezone).

EnableCameraIfyouhaveaRaspberryPiCameramodule,youneedtoenableitusingthismenuoption.AddtoRastrack

Rastrack(rastrack.co.uk)showsthelocationofRaspberryPidevicesaroundtheworld.UsethisoptiontoaddyourPitothemap.

OverclockOverclockingyourPimakesitrunfasterthanthe

manufacturerdesigneditto.However,thiscanalsocausethesystemtooverheatorbecomelessstable.

AdvancedOptionsSeebelow.Aboutraspi-configDisplayinformationabouttheraspi-configtool.

SelectingAdvancedOptionsfromthemenutakesyoutoanothermenu:MenuOptionDescriptionOverscanThedisplayinmanyoldertelevisionsisslightly

largerthanthevisiblearea.IfyourPisdisplayrunsofftheedgeofthescreen,youcanenableblackborders(overscan)toensurethatyoucanseeallofthepicture.

HostnameChangethenamegiventothePiwhenitis

connectedtoalocalnetwork.Thiscanbeusefulwhensearchingforthedevice,orwhenyouhaveseveralRaspberryPidevices.

MemorySplitThePismemoryissharedbetweentheCPUandGPU.YoucanchangehowmuchmemoryisallocatedtotheGPUusingthissetting.SSHEnableordisableSSHaccess.SPIWhenconnectingcertainSPIdevices,itcanbe

usefultoloadtheSPIkernelmodulewhenthePistarts.Usethissettingtochangewhetherthemoduleisloadedautomatically.

Audio

Usedtosendtheaudiosignaltotheaudiooutputconnector,evenwhenusinganHDMIcableforvideo.

UpdateConnectstotheInternetandupdatestheraspiconfigtooltothelatestversion.

Forsomeusers,thedefaultsettingsareok.However,therearethreesettingsinparticularthatmanyusersmightwanttochangeatthisstage:

ChangingtheDefaultPasswordWhenRaspbianisinstalled,itcreatesanewusercalledpi.Thedefaultpasswordforthisuserisraspberry.

Tochangethis:1.PresstheDownArrowkeytohighlightChangeUserPassword,andthenpressEnter.

2.PressEnteragaintoselect.3.TypeanewpasswordandpressEnter.

4.Toconfirmthepassword,typeitagainandpressEnter.5.PressEntertoselect.

IfyouconnectyourPitotheInternetandareunsurewhetheryournetworkrouterallowsincomingconnectionsthenitisagoodideatochangethispasswordsothatotherpeoplecannotlogintoyourdevice.

ExpandingtheFileSystemIfyouinstalledRaspbiantotheSDcardusingadiskimage,itispossiblethattheOScannotusethefullcapacityofyourSDcard.

Tofixthis:1.UsetheUpandDownArrowkeystohighlightExpandFilesystemandthenpressEnter.2.Whentheprocessiscomplete,pressEntertoselect.

3.PresstheTabkeyandthentheRightArrowkeytohighlight.PressEnter,andwhenyouarepromptedtorebootthePi,select.

ChangingtheDefaultBootSequenceThedefaultsettingisforRaspbiantofinishloadingandplaceyouatthecommandline.

Fromtheraspi-configtool,youcaninstructRaspbiantoloadthegraphicalenvironmenteverytimetheRaspberryPistartsup.Todothis:

1.UsetheUpandDownArrowkeystohighlightEnableBoottoDesktop/Scratch,andthenpressEnter.

2.PresstheDownArrowkeytohighlightDesktopLoginasuserpiatthegraphicaldesktop,andthenpressEnter.

2.5RaspbiansDesktopEnvironment

Ifyouhavenotchangedthesettinginraspi-config,theRaspberryPiwillbootintoRaspbianscommandline.Tostartthedesktopenvironment:

1.Typepiastheusername,thenpressEnter.2.Typeyourpassword,thenpressEnter.13.TypethefollowingcommandandpressEnter:startxAfterashortperiodofloading,youwillseeascreensimilartoFigure2.1.Ifyouhavenotchangedthedefaultpassword,itisraspberry.

Figure2.Raspbiansdesktopenvironment

RaspbiansdesktopisacustomizedversionofLXDE,whichstandsforlightweightX11desktopenvironment.ItissimilartoMicrosoftWindowsandmanyofthewaysthatyouuseitarethesame.

Thescreenisdividedintotwodistinctareas:thedesktop,andtheLXDEpanel.

Figure3.ElementsoftheRaspbiandesktopenvironment1Desktoparea.Hereyoucanfindfilesandlinks(shortcuts)toapplications.Double-clicktheiconstoopenthefileorapplicationthatitlinksto.

2LXDEpanel.Containsthemainmenu,shortcutstocommonly-usedapplications,thedesktoppager,andthesystemtray.3Menu.TheLXDEmainmenuprovidesaccesstomanyofthesystemsettings,tools,andanyapplicationsthatyouhaveinstalled.4DesktopPager.Formoreinformation,seeSwitchingtheDesktoponpage29.

5Taskbar.Openapplicationsareshownasaniconanddescriptioninthisarea.Ifyouminimizeanapplicationwindow,youcanclicktheiconintheLXDEpaneltorestorethewindowtofullview.

6SystemTray.Thisisusuallyusedbysystemprocessesandapplicationsthatruninthebackground,sothattheuserhassomewayofinteractingwiththem.Bydefault,thesystemtraycontainstheCPUmonitor(whichshowshowbusyistheCPUis),thecurrenttime,andtheapplicationlaunchbar(anotherplaceyoucanstoreiconstoopencommonly-usedapplications).Youcanusuallydouble-clicktheiconsinthisareatoopentheirwindow,orrightclicktheicontoaccesstheapplicationsmenu.

OpeningandClosingApplicationsOnthedesktop,andinthemenuthatyouaccessfromtheLXDEpanel,youcanseethatmanyapplicationsarealreadyinstalledonyoursystem.

ThereareseveralwaysofrunningapplicationsinRaspbian,butthethreemostcommonare:clickingiconsonthedesktop,usingthemenu,andopeninganapplicationfromthecommandline.

Forexample,toopenthewebbrowserMidori:Onthedesktop,double-clickMidori.OntheLXDEpanel,clicktheMenubutton.PointtoInternet,andthenclickMidori.

Fromacommand-lineterminalrunninginthedesktopenvironment,typemidoriand

thenpressEnter.Ifyourunapplicationsfromthecommandline,youwillreturntothepromptwhentheyarefinished.Withapplicationsthatopenawindowinthegraphicalenvironment,youcanclosetheminthreeways:

PressAlt+F4onthekeyboard.ClicktheClosebuttoninthetop-rightofthewindow.Itlookslikeanx.Clicktheiconinthetop-leftofthewindow,andthenclickClose.

SwitchingtheDesktopOnmostLinuxdesktopenvironments,youcanhavetwo(ormore)workspaces.Aworkspaceiscollectionofthewindowsandfilesthatarecurrentlyopen.Switchingtoanotherworkspacehidesallofthewindowsthatarecurrentlyvisible,anddisplaysallofthewindowsfromtheotherworkspace.InRaspbian,workspacesarealsocalleddesktops.

YoucanswitchbetweentheseusingthetwodesktopbuttonsthatmakeuptheDesktopPager.Forexample:1.Onthedesktop,double-clickMidori.2.Dragthewindowtothetop-rightcornerofthedisplay.3.Onthedesktop,double-clickLXTerminal.

4.OntheLXDEpanel,pointtothelightgraysquare.Afterafewmoments,thetextDesktop2willappear.Clickthebutton.

5.Onthedesktop,double-clickPiStore.

6.ClicktheDesktop1button(totheleftoftheDesktop2button)toswitchbacktothefirstdesktop.

7.ClicktheDesktop2buttontoswitchtotheseconddesktopagain.Tomoveawindowtoanotherdesktop:clicktheiconinthetopleftofawindow,pointtoSendtodesktop,andthenclickthenameofthedesktop.

Toincreasethenumberofdesktopsthatyoucanuse:

1.OntheLXDEpanel,right-clicktheDesktopPager.2.ClickDesktopPagerSettings.

3.OntheDesktopstab,typeanumberintotheNumberofdesktopsbox,orusetheupanddownarrowbuttonstoincreaseanddecreasethenumberofdesktops.

4.ClickClose.

UsingtheFileManagerYoucanusetheFileManagertocopy,rename,delete,andchangethepropertiesoffilesthatarestoredontheSDcardoranyUSBstoragedevicesthatyouhaveattached.

Toopenthefilemanager:OntheLXDEpanel,clicktheFileManagerbuttonthesecondbuttonfromtheleft;orOntheLXDEpanel,clicktheMenubutton,pointtoAccessories,andthenclickFileManager.1

23

456

Figure4.TheFileManager

1Applicationmenu.2Toolbarnavigationbuttonsandaddressbar.3Tabbar.4Leftpanelforselectingplaces,devices,andfiletrees.5Rightpanelforselectingfilesandfolders.6Statusbar.

Likeawebbrowser,theFileManagerwindowcanopenmultiplefoldersatthesametimebyusingtabs.Toopenanewtab:Onthetoolbar,clickthefirstbuttonfromtheleft.

Thiswillcreateanewtabinthesamefolder,andwillshowthetabbar.Youcanusethetabbartoswitchbetweenthetabsthatarecurrentlyopen.

IfyouhaveusedtheWindowsExplorerinMicrosoftWindowsortheFinderinMacOSX,youalreadyknowhowtocompletemanyofthemostcommontasks.However,thetablebelowisabriefsummaryofhowtousetheRaspbianFileManager.ToDoThis

SwitchbetweenthePlacesviewandthefulldirectorytreeIntheleftpanel,clickPlacesandthenclickDirectoryTree.

Changethewayiconsfilesandfoldersaredisplayedintherightpanel

Ontheapplicationmenu,clickView,andthenclickononeofthefourviewoptionsIconView,ThumbnailView,CompactVieworDetailedListView.

OpenafolderIntheleftpanel,clickthenameofafolder.Intherightpanel,doubleclickfoldersicon.OpenafolderusingafilepathIntheaddressbar,typethefullfilepathandthenpressEnter.ToDoThis

OpenthecurrentusershomedirectoryOntheapplicationmenu,clickGo,andthenclickHomeFolder;oronthetoolbar,clicktheHomebutton.

OpenthedesktopfolderOntheapplicationmenu,clickGo,andthenclickDesktop.

OpenthecurrentfolderinthecommandlineOntheapplicationmenu,clickTools,andthenclickOpenCurrentFolderinTerminal.

SelectafileorfolderIntherightpanel,clickanicon.SelectmultiplefilesorfoldersIntherightpanel,holdCtrlandclicktheiconsofthefilesandfoldersthatyouwanttoselect.DeleteafileorfolderRight-clickaniconandthenclickDelete.RenameafileorfolderRight-clickaniconandthenclickRename.

ViewthepropertiesofafileorfolderRight-clickaniconandthenclickProperties.

OpenafileinitsdefaultapplicationDouble-clickafilesicon.

MoveafileorfoldertoanewlocationRight-clickaniconandthenclickCut.Browsetothefolderthatyouwanttomovetheitemto,right-clickintherightpanel,andthenclickPaste.

CopyafileRight-clickaniconandthenclick

Copy.Browsetothefolderwhereyouwantacopytobecreated,right-clickintherightpanel,andthenclickPaste.

Createanewfolder

Right-clickintherightpanel,pointtoCreateNew,andthenclickFolder.

IfyouareusedtoMicrosoftWindows,theLinuxfilesystemmightseemalittlestrangeatfirst.Itcontainsalargenumberoffolders,andmanyofthesehavespecificpurposes.Thekeyonesare:FolderDescription

homeContainsafolderforeachuseraccountonthesystem.Forexample,/home/piisthehomefolderforthedefaultuseronRaspbianinstallations.Thisiswhereyoushouldstoreallofyourpersonalfiles.

etcContainsmostoftheconfigurationfilesfortheoperatingsystem.

devLinuxcreatesfilesystementriesinthisfolderforhardwaredevicesthatareattachedtothesystem.Mediadevices(forexample,DVDdrives)areplacedin/mntor/mediainstead.

mediaWhenstoragedevicessuchasCDs,memorycards,andUSBflashdrives,areinserted,thesystemcreatesamountpointfortheminthisfolder.Mountpointsprovideaccesstothefilesystemonthedevice.

rootThisisthehomefolderforthesystemadministratoraccount.tmpTemporaryfilesusedbythesystem.ThecontentsofthisfolderaredeletedwhenthePistarts.bootContainsfilesneededtostartRaspbian.

varStoresvariableandtemporaryfilesthatarecreatedbytheuserorapplicationsrunningastheuser.

binContainsapplicationsthatareusedbyalluseraccounts,thesystem,andthesystemadministrator.

usrContainsapplicationsanddocumentationforalluserapplications.sbinContainsapplicationsthatareonlyavailabletothesystemandthesystemadministrator.FolderDescription

libContainslibrariescollectionsofcodeandinformationthatmustbesharedamongallapplications.

mntSimilarto/media,thisfoldercontainsmountpointsfornon-removablemedia.

Ingeneral,trytokeepallofyourdatainthe/home/pifolder.Wheninstallingnewsoftwareandhardwaredevices,theywillusethespecialfoldersiftheyneedto.

AccessingtheCommandLineWhilemosttaskscanbecompletedusingthedesktopenvironment,therearestillsomethingsthatyouwillhavetodofromthecommandline.

Toaccessthecommandlinefromthegraphicalenvironment:Onthedesktop,double-clickLXTerminal.OntheLXDEpanel,clicktheMenubutton,pointtoAccessories,andthenclickLXTerminal.

Inthecommandline,filesandfoldershavefilenamesandfilepaths.Thefilepathincludesthenamesofthefoldersandsubfoldersthatthefileisstoredin.Forexample,afileocr_pi.pnginthepiusershomefolderhasthefullfilepath:/home/pi/ocr_pi.png

Filepathsthatbeginwithaforwardslashstartfromthetop-levelfolder.Sotheexampleabovetellsthesystem:startatthetoplevelandmoveintothehomefolder,thenmoveintothepisubfolder,andthenfindthefileocr_pi.png.

Ifyouarealreadyinthehomefolder,youcanrefertothesamefileas:pi/ocr_pi.png

Andifyouareinasubfolderof/home/pi,youcanrefertothefileusingtwodotsthatsymbolizemovingtotheparentdirectory:../ocr_pi.png

Toruncommands:typethecommandusingthekeyboardandthenpressEnter.Therearealargenumberofcommandsavailable(toomanytolisthere),butthesearesomeofthemostcommon:ToDoThisListthecontentsofthecurrentfolderTypelsandthenpressEnter.ListthecontentsofaspecificfolderTypelsfollowedbyaspaceandthenthenameofthefolder.ThenpressEnter.MoveintoasubfolderTypecdfollowedbyaspaceandthenthenameofthefolder,andthenpressEnter.MovetoaparentfolderTypecd..andthenpressEnter.CreateasubfolderTypemkdirfollowedbyaspaceandthenthenameofthefolder,andthenpressEnter.DeleteafolderTypermdirfollowedbyaspaceandthenthenameofthefolder,andthenpressEnter.DeleteafileTypermfollowedbyaspaceandthenthenameofthefile,andthenpressEnter.CopyafileorfolderTypecpfollowedbyaspaceand

thenthename(orfullfilepath)ofthefiletobecopied.Typeanotherspaceandthenthename(orfullfilepath)tocallthecopy.PressEnter.

RenameormoveafileorfolderTypemvfollowedbyaspaceand

thenthename(orfullfilepath)ofthefiletobecopied.Typeanotherspaceandthenthename(orfullfilepath)tocallthecopy.PressEnter.

ClearthecommandlinewindowTypeclearandthenpressEnter.

Toclosethecommandline,dooneofthefollowing:PressAlt+F4onthekeyboard.ClicktheClosebuttoninthetop-rightofthewindow.

Clicktheiconinthetop-leftofthewindow,andthenclickClose.Ontheapplicationmenu,clickFileandthenclickQuit.TypethefollowingcommandandthenpressEnter:exit

IntheAccessoriesgroupoftheLXDEpanelmenu,thereisanotherterminal.ThisoneiscalledRootTerminal.Whenyouopenthecommandlineusingthisapplication,youareautomaticallygrantedsystemadministratorprivileges.Ifyouonlywanttorunasinglecommand,youcandothisfromtheRaspbianmenu.OntheLXDEpanel,clicktheMenubuttonandthenclickRun.TypeyourcommandandthenpressEnter.

UnderstandingLinuxUsersandSuperusersIfyouhaveusedmorerecentversionsofMicrosoftWindowsthenyoumaybeusedtorunningcertainapplicationsasanadministrator.ThisconceptisalsoinLinux.

Superusers(oftencalledroot)havefullaccesstothesystem.Anyapplicationsyourunasasuperuserwillalsohavefullaccesstothesystem.Toprotectthesystemfromaccidentalormaliciousdamage,yourarelylogintoRaspbianasasuperuser.

NormalusershavelessaccesstothecorefilesneededbytheOS,andthismeansthatanyapplicationsthattheyrunalsohavelessaccesstothesystem.InRaspbian,piistheuserthatlogsintothedesktopenvironment,anditisanormaluser.

Whenyoudoneedtochangepartofthesystem,oraccomplishataskthatonlysuperusercando,youcan:OntheLXDEpanel,clicktheMenubutton,pointtoAccessories,andthenclickRootTerminal;or

Fromthenormalcommandline,typesudofollowedbyaspacebeforethecommandthatrequiressuperuseraccessprivileges.

2.6CommonTasks

Inthissection,youcanfindinstructionsforsomeofmostcommontasksthatpeopleperformafterinstallingRaspbian.Theseinstructionscontinueintothenextsection,2.7NetworkConnectionsandRemoteAccessonpage40.

RestartingandShuttingDowntheRaspberryPiTorestartthePi:1.OntheLXDEpanel,clicktheMenubuttonandthenclickRun.2.TypethefollowingcommandandthenpressEnter:sudoshutdownrnowToshutdownthePifromthedesktop:1.Onthedesktop,double-clickShutdown.2.ClickYes.ToshutdownthePifromthecommandline:TypethefollowingcommandandthenpressEnter:sudoshutdownhnow

ConfiguringtheTVServiceIfyouconnectyourPitoatelevisionusinganHDMIcable,Raspbianautomaticallyselectsascreensizethatitdecideswillbethebestforyoursetup.However,thisisnotalwaysthehighestresolution.

TheconfigurationsettingthatcontrolshowRaspbianselectsthescreensizeisinthefile/boot/config.txtandyoucanadjustthissettingwithatexteditor:1.OntheLXDEpanel,clicktheMenubutton,point

toAccessories,andthenclickRootTerminal.2.TypethefollowingcommandandthenpressEnter:tvservicededid3.TypethefollowingcommandandthenpressEnter:edidparseredid

4.Findthevideomodethatyouwanttouse,andmakenoteofthemodenumberandwhetheritsaysDMTmodeorCEAmode.

5.TypethefollowingcommandandpressEnter:nano/boot/config.txt

6.PresstheDownArrowkeyuntilyoufindthelinesthatbeginwith#hdmi_group=#hdmi_mode=

7.Removethe#fromthestartofbothofthoselines.8.IfthevideomodeisDMT,changethehdmi_groupto2:hdmi_group=29.IfthevideomodeisCEA,changethehdmi_groupto1:hdmi_group=110.Typethemodenumberafterhdmi_mode=,forexample:hdmi_mode=1611.PressCtrl+X.12.PressY,andthenpressEnter.13.RestarttheRaspberryPi.

InstallingaGraphicalPackageManagerWheninstallingnewapplications,thereareafewstepsthatneedtobetaken:1.Findoutwhethertheapplicationiscompatiblewith

theOS.2.Installanyotherpiecesofsoftwarethatthisnewapplicationrequires.3.DownloadtheapplicationfromtheInternet.4.Installtheapplicationtothecorrectfolders.

InLinux,thepackagemanagerhandlesallofthisforyou.Youcanalsouseittouninstallapplicationsthatyoudonotwantanymore.Packagemanagersconnecttorepositoriesonlinelibrariesofsoftware.AndsinceLinuxisopen-source,mostofthesoftwareintheserepositoriesisalsoopen-source(andfree).

Thepackagemanagerthatisbuilt-intoRaspbianisaccessedfromthecommandline.However,youcanalsoinstallonethatrunsinthegraphicaldesktopenvironment.

OnesuchtoolisSynaptic.Toinstallit,usethecommand-linepackagemanager:1.OntheLXDEpanel,clicktheMenubutton,pointtoAccessories,andthenclickRootTerminal.

2.TypethefollowingcommandandthenpressEnter:apt-getinstallsynaptic

3.Whentheprocessiscomplete,typethefollowingcommandandthenpressEnter:exitToruntheSynapticpackagemanager:

OntheLXDEpanel,clicktheMenubutton,pointtoPreferences,andthenclickSynapticPackageManager.

2.7NetworkConnectionsandRemoteAccess

SettingupWi-FiBeforebuyingaUSBWi-FiadapterforusewiththeRaspberryPi,checkthattheadaptorisknowntobeworkingbylookingatthelistathttp://elinux.org/RPi_USB_Wi-Fi_Adapters

ToinstallaUSBWi-FiadapteronyourPiandconnecttoyournetwork:1.InserttheUSBdeviceintoanavailableUSBsocketonthePi,oronaUSBhub.2.Onthedesktop,double-clickWiFiConfig.

3.IntheAdapterlist,clickwlan0.Ifyouhavenoadaptersinthelist,yourUSBdeviceisnotcompatiblewiththeRaspberryPi.

4.ClickScantoopentheScanresultswindow.5.ClickScan.6.Double-clickthenameofyourWi-Finetwork.

7.CheckthattheAuthenticationandEncryptionsettingsmatchhowyourothercomputersconnecttoyourrouter.

8.TypeyournetworkpasswordintothePSKbox.9.ClickAdd,andthenclickClose.

FindingtheIPAddressToconnecttothePifromanothercomputeronyournetwork,youwillneedtoknowitsIPaddress.Tofindthis:

1.Onthedesktop,double-clickLXTerminal.2.TypethefollowingcommandandthenpressEnter:ifconfig

Theaddressyouneediscalledinetaddrandconsistsoffournumbersseparatedbydots.IfyouareconnectedtoyournetworkusinganEthernetcable,youcanfindtheaddressinthesectionlabelledeth0.Ifyouareconnectedtoyournetworkusingawirelessadaptor,youcanfindtheaddressinthesectionlabelledwlan0.

UsingaStaticIPAddressWhenthePirestarts,orreconnectstothenetwork,yournetworkrouterwillgivethePianIPaddress.However,thiscanchangeeverytime.

YoucanconfigurethePisothatitalwaysusesthesameIPaddress.Youneedafewpiecesofinformationandyouwillneedtoeditaconfigurationfileinatexteditor.

Todothis:

1.Onthedesktop,double-clickLXTerminal.2.TypethefollowingcommandandthenpressEnter:ifconfig

3.IfyouareusinganEthernetcable,inthesectionlabelledeth0,makeanoteofthevaluesinetaddr,BcastandMask.

4.IfyouareusingWi-Fi,inthesectionlabelledwlan0,makeanoteofthevaluesinetaddr,BcastandMask.

5.TypethefollowingcommandthenpressEnter:netstat-nr

6.MakeanoteofthevaluesinGatewayandDestination.Ifyoucanseetwoentriesinthetable,ignorethevalues0.0.0.0andusethevaluefromtheotherline.

7.TypethefollowingcommandandthenpressEnter:sudonano/etc/network/interfaces8.IfyouareusingWi-Fi,skiptostep12.

9.IfyouareusinganEthernetcable:changethelinethatreadsifaceeth0inetdhcptoifaceeth0inetstatic

10.Addthefollowinglines,startingonanewlineafterthewordstatic.Replacethevaluesinangledbracketswiththevaluesfromtheprevioussteps:addressnetmasknetworkbroadcastgateway

11.Skiptostep14.12.IfyouareusingWi-Fi:changethelinethatreadsifacewlan0inetdhcptoifacewlan0inetstatic13.Addthefollowinglines,startingonanewlineafterthewordstatic.addressnetmaskgateway

14.PressCtrl+X.15.PressY,andthenpressEnter.16.RestarttheRaspberryPi.

TransferringFilestoandfromtheRaspberryPiYoucanusesecurecopy(SCP)totransferfilesfromyourcomputertoaPi,ortocopyfilesfromthePitoanothercomputer.Raspbianalreadysupportsthis,andsoyouonlyneedtoinstallaclientonyourmaincomputer.

OnWindows,WinSCPisverypopularapplicationfortransferringfiles.Youcandownloaditforfreeathttp://winscp.net

OnMacOSX,youcanuseanapplicationcalledCyberduck.Thisisafreedownloadfromhttp://cyberduck.io/oryoucandownloaditfromtheMacAppStore.

ThedetailsyouneedtomakeaconnectiontothePiarelargelythesameregardlessofwhichSCPclientyouuse:

Server/Hostname:theIPaddressofyourPiUsername:piPassword:thisisraspberryifyouhavenotyetchangedit.Protocol:SCP

TodownloadfilesfromthePi,dragtheiconsfromtheSCPclientswindowtoaWindowsExplorerorFinderwindow.TouploadfilestothePi,dragfilesfromaWindowsExplorerorFinderwindowanddropthemontotheSCPclientswindow.

ConnectingtothePiwithSSHSecureshell(SSH)isawayoftalkingtoyourPioveranencryptedtransmission.ItistypicallyusedwhenyouwanttoaccesstheRaspberryPiscommandlinefromanothercomputer.AslongasyourPihasanetworkconnection,youcanconnecttoitremotelyandtypecommands.

OnWindows,youwillneedanapplicationthatunderstandstheSSHprotocol.Therearemanyoftheseavailable,butPuTTYisoneofthemorepopularones.Downloaditfromhttp://www.chiark.greenend.org.uk/~sgtatham/putty/

YoudonotneedanadditionalSSHclienttoconnecttothePionMacOSX.ToconnecttoyourPioverSSHonWindows(8/7/Vista/XP):1.Locatethefileputty.exethatyoudownloaded,andthendouble-clickit.2.IntheHostName(orIPaddress)box,typetheIPaddressofyourPi.

3.ClickOpen.4.Attheloginprompt,typepi.

5.Atthepasswordprompt,typeyourpasswordandpressEnter.Thisisraspberryifyouhavenotchangedit.

ToconnecttoyourPioverSSHonMacOSX:

1.Onthedock,clickFinder.2.Onthesidebar,clickApplications.3.ClickUtilities,andthendouble-clickTerminal.

4.Typethefollowingcommand,replacingwiththeIPaddressofyourRaspberryPi:sshpi@5.PressEnter.6.Atthepasswordprompt,typeyourpasswordandpressEnter.Thedefaultpasswordisraspberryifyouhavenotchangedit.

ConnectingtothePiwithRemoteDesktopMicrosoftWindowscomeswithanapplicationcalledRemoteDesktop.YoucanusethistoconnecttoyourRaspberryPiandusethedesktopenvironmentfromaWindowscomputer.MacOSXusersneedtodownloadMicrosoftRemoteDesktopfromtheMacAppStore.

YoualsoneedtoinstallasmallsoftwareapplicationonthePibeforeyoucanconnectusingRemoteDesktop.Toinstallthesoftwarefromthecommandline:1.OntheLXDEpanel,clicktheMenubutton,pointtoAccessories,andthenclickRootTerminal.2.TypethefollowingcommandandthenpressEnter:apt-getinstallxrdpTostartaRemoteDesktopconnectionfromWindows(8/7/Vista/XP):1.PresstheWindowslogokey+R.ThentypemstscandpressEnter.2.IntheComputerbox,typetheIPaddressofyourRaspberryPi,andthenpressEnter.3.IntheLogintoxrdpwindow,intheusernamebox,typepi.4.Inthepasswordbox,typeyourpassword.15.ClickOK.

BrowsingtheWebIfyouareusingthelatestversionofRaspbian,thewebbrowseriscalledEpiphanyanditisinstalledwhenyouinstalltheOS.Inotherversions,thewebbrowserisMidori.

Toopenawebbrowser:

OntheLXDEpanel,clicktheMenubutton,pointtoInternet,andthenclickMidoriorEpiphanyWebBrowser.

2.8OtherOperatingSystems

RaspbianLinuxisnottheonlyOSthatyoucanrunonaRaspberryPi.ManyvarietiesofLinuxhavebeenrepackagedsothatyoucanusethem,andthereareseveralnon-Linuxoperatingsystemsthatalsowork.

ArchLinuxArchLinuxisanextremelylightweightversionofLinuxthatisidealforserversordeviceswithunusualpurposeswheremanyofthepackagesthatarenormallyinstalledtocreateausabledesktopenvironmentarenotneeded.

YoucandownloadadiskimageofArchLinuxfromhttp://www.raspberrypi.org/downloads/,oritcanbeinstalledusingNOOBS.

RISCOSRISCOSisavailableathttp://www.raspberrypi.org/downloads/oryoucaninstallitusingNOOBS.Ithasbeeninusesince1987,andwasdesignedforArchimedeslineofcomputersmadebyAcornComputersLtd.ThesemachinesusedthefirstARMprocessors.1.Ifyouhavenotchangedthedefaultpassword,itisraspberry.

RetroPieRetroPieisacustomizedversionofRaspbianthatrepackagestheOSwithavarietyofemulatorsforclassiccomputersandvideogamesconsoles.Findoutmoreathttp://blog.petrockblock.com/retropie/

Plan9Plan9isdevelopedbyBellLabs,andhasitsoriginsinanOSthatwasreleasedinthe1980s.Itisverylightonsystemresources,andquitedifferentfromtheoperatingsystemsthatpeopleareusedtotoday.YoucandownloadadiskimageofPlan9fromhttp://plan9.bell-labs.com/wiki/plan9/download/

AEROSAROSisdesignedtobeasuccessortotheoperatingsystemAmigaOS,whichisitselfbasedontheoperatingsystemusedbytheCommodoreAmigarangeof16-bitcomputers.TheRaspberryPiversioniscalledAEROS.Thecurrentversionisonlyavailabletoregisteredusers,butolderversionsareavailableathttp://www.aeros-os.org/styled-11/index.html

AndroidAndroidisanoperatingsystemfortabletsandsmartphones,butitisnotyetfullyusableontheRaspberryPi.Thewebpageforthisprojectishttp://androidpi.wikia.com/wiki/Android_Pi_Wiki

NoOperatingSystemIfyouareanexperiencedsoftwaredeveloperandyoudonotneedtorunanyotherapplications,thenyoumightbeabletorunyourcodewithoutinstallinganoperatingsystem.Thisiscalledbare-metalprogrammingandtherearevarioustutorialsandsamplesavailableonthewebtohelpyou.

3BuildingaMediaCenterwithXBMC

3.1XBMC

XBMCisamediaplayerthatisdevelopedbytheXBMCFoundation.Asamulti-platform,highly-customizable,andopensourcesoftwarepackage,itisextremelypopularandisusedonawidevarietyofdevices.

XBMCcanplayaudioandvideofilesinmanyformats,including:3GP,AAC,APE,AVI,CDDA,FLV,MIDI,MKV,MP3,MP4,M4A,MPEG,OGG,WAV,WMA,WMV,andmanymore.1ItcanevenplayDVDsfromISOdiscimages.

ManypeoplehaveaRaspberryPispecificallyforthepurposeofrunningXBMC.ThePiscompactsize,lowcost,supportforUSBdevicesandnetworking,andbuilt-inHDMIoutputmakeitanexcellentchoiceforamediaplayerthatsitsnexttotheTVanddoesnottakeupalotofspace.ThecurrentversionofXBMCfortheRaspberryPiis13.2Gotham.WhentheXBMCFoundationreleaseversion14ofthesoftware,theywillrenameXBMCtoKodi.

Inthischapter,youcanseehowtoinstallXBMConyourPi.Youwillalsolearnthebasicsofhowtoworkwiththeuserinterface,andhowtoaddmediafilestothesystem.

Tocompletethistutorial,youneed:ARaspberryPi(anymodel)connectedtoyourlocalnetworkandwithaccesstotheInternet.Akeyboardandmouse.AUSBstoragedevice,suchasamemorystickorharddrive.1.ForthecompletelistofcontainerformatsandcodecsthatXBMCsupports,seehttp://wiki.xbmc.org/index.php?title=Features_and_supported_formats

3.2Installation

IfyouhaveablankSDcardthatyouwillbeusingforyourmediacenterthenyoucaninstalltheoperatingsystemandXBMCtogether.RaspBMCandOpenELECaretwoLinuxdistributionsthatalreadycontainXBMC,andyoucaninstallthesefromNOOBS.FormoreinformationaboutinstallingoperatingsystemsusingNOOBS,seesection2.2InstallationofRaspbianwithNOOBSonpage16.

TostartNOOBSwhenanexistingOSisalreadyontheSDcard:turnoffthePi,andthenholdtheShiftkeyasyouturnthePibackonanduntilyouseetheNOOBSwindow.NOOBScaneitherremoveyourexistingOS,oraddRaspBMCorOpenELECasanadditionaloption.ToremoveanOS,unchecktheboxnexttoitbeforeyouclickInstall.IfyouleaveyourexistingOSontheSDcard,youwillbeaskedtochoosewhichoneyouwanttoloadwhentheRaspberryPistartsup.

IfyoucannotuseNOOBS,youcanalsodownloaddiskimagesofthedistributionsfromhttp://www.raspberrypi.org/downloads/andthenrefertosection2.3InstallationofRaspbianusingaDiskImageonpage20formoreinformationabouthowtowritethefiletoanSDcard.

IfRaspbianisalreadyinstalledonyourcardandyouwanttoaddXBMCtoit,installingXBMCusuallyonlytakesafewminutes.Tobegin,youneedtoaddMichaelGorvensrepositorytothelistofapplicationsourcesinLinux:

1.OntheLXDEpanel,clicktheMenubutton,pointtoAccessories,andthenclickRootTerminal.

2.TypethefollowingcommandandthenpressEnter:nano/etc/apt/sources.list.d/mene.list3.Typethefollowingtextasthefirstlineinthefile:debhttp://archive.mene.za.net/raspbianwheezycontrib4.PressCtrl+O,andthenpressEnter.5.PressCtrl+X.6.Typethefollowingcommandononeline,andthenpressEnter:apt-keyadvkeyserverkeyserver.ubuntu.com-recv-key5243CDED7.TypethefollowingcommandandthenpressEnter:apt-getupdateToinstallXBMCfromthecommandline:TypethefollowingcommandandthenpressEnter:apt-getinstallxbmc

XBMCdoesnotworkcorrectlyif64MBorlessmemoryisallocatedtotheGPU.AsthisisthedefaultsettingforRaspbianinstallations,youneedtochangeitinraspi-config:

IntheRootTerminal,typethefollowingcommandandthenpressEnter:raspi-configor,ontheLXDEpanel,clicktheMenubutton,andclickRun.TypethefollowingcommandandthenpressEnter:sudoraspi-config

WhentheRaspberryPiSoftwareConfigurationToolappears:

1.PresstheDownArrowkeyrepeatedlyuntilAdvancedOptionsishighlighted,and

thenpressEnter.2.PresstheDownArrowkeytwicetoselectA3MemorySplit.PressEnter.3.Changethevalueto128andthenpressEnter.4.PresstheRightArrowkeytwicetoselect.ThenpressEnter.5.PressEntertoselectandrebootthePi.

RunningXBMCXBMCisastandaloneapplicationanddoesnotrunthedesktopenvironment.Torunit,youmustdropbacktothecommandline:pressCtrl+Alt+F1.Toreturntothedesktopenvironment,pressAlt+F7.

TostartXBMC:TypethefollowingcommandandthenpressEnter:xbmc-standalone

However,startingXBMCthiswayreducestheamountofmemoryandsystemresourcesavailabletoit.IfyouwanttouseyourRaspberryPiasadedicatedmediaplayerandautomaticallyrunXBMCwhenitstartsup:

1.OnacommandlineorLXTerminal,enterthefollowingcommandandpressEnter:sudonano/etc/default/xbmc2.ChangeENABLED=0toENABLED=13.ChangeUSER=xbmctoUSER=pi4.PressCtrl+X,thenpressY,andthenpressEnter.5.TypethefollowingcommandandthenpressEnter:sudoraspi-config6.PresstheDownArrowkeytwicetohighlightEnableboottoDesktop/ScratchandthenpressEnter.7.HighlightConsoleTextconsole,requiringlogin(default)andthenpressEnter.8.PresstheRightArrowkeytwicetohighlight,andthenpressEnter.9.PressEntertoselect.

3.3FirstSteps

OnceXBMCisfinishedloaded,youshouldseeascreensimilartoFigure1below.

Figure1.TheXBMChomescreen

1Recentvideos.WhentheMoviesorTVShowsmenuoptionishighlighted,XBMCwillshowthefilesthathavemostrecentlybeenaddedtoyourlibrary.Youcanclickoneoftheseitemstostartplaying.

2Mainmenu.

3Favorites.Clickthisbuttonforquickaccesstoitemsthatyouhaveplacedinyourfavoriteslist.Toaddanitemtoyourfavorites,rightclickittoopenitscontextmenu.

4Exit.TocloseXBMCandreturntotheLinuxcommandline,clicktheExitbutton,andthenclickExit.

AllofXBMCsfeaturescanbeaccessedusingitsmouse-drivenmenusystem,yougenerallyonlyneedtousethekeyboardfortypinginconfigurationsettings.

Tocontrolthehomescreenmenu:Movethemousepointertothefarleftandfarrightsidesofthemenutoscrollit.Pointtoamenuitemtobringupanyoptionsthatareavailableinthatcategory.

Clickamenuitem(oroptionunderneath)toopenit.Mostmenuitemsopenadifferentscreenwhenyouclickthem.Tocontrolthesescreens:

Clickwiththeleftmousebuttontoactivatemenuitemsandbuttons.

Right-clickanareaofthescreenthatdoesnotcontainamenuitemorbuttontomovetothepreviousscreen.

Right-clickamediafileorfoldertobringupacontextmenuwhichhasadditionaloptionsthataffecttheselecteditem.

Toopenthesidebar,movethemousepointerovertothetabontheleftsideofthescreen.Toclosethesidebar,movethemousepointerawaytotheright.

ClicktheBackbuttontoreturntothepreviousscreen.ClicktheHomebuttontoreturntothehomescreen.

Figure2.TheMoviesbrowserandthesidebar

XBMCdividesmediafilesintocategoriesdependingonwhethertheyareamoviefile,anepisodeofaTVshow,amusicfile,apictureorphoto,oraprogram.Thedifferenttypesoffileareaccessedusingdifferentmenuitemsonthehomescreenmenu.

ChangingtheXBMCSkinTheRaspberryPiversionofXBMCusesaninterfacetheme(orskin)calledConfluence.Ifyouwanttochangethis,youcandownloadnewskinsdirectlyfromtheXBMCsystemsettings.

Todownloadandenableanewskin:1.OntheXBMCHomescreen,clickSystem.

2.ClickAppearance,andthenclickthefirstitemintherightpanel.ThisitemhasthewordSkinononeside,andConfluenceontheorder.

3.ClickGetMore4.Pointtoeachskintoloadapreviewanddescription.5.Todownloadaskin,clickit,andthenclickInstall.6.Whenaskedifyouwanttoswitchtothisskin,clickYes.TochangetheskinbacktoConfluence:1.OntheXBMCHomescreen,clickSystem.2.ClickAppearance,andthenclickthefirstitemintherightpanel.3.ClicktheConfluenceskin.

ThebasiccontrolsforusingXBMCdonotchangewithdifferentskins.However,thelayout,colors,andthewaymediafilesaredisplayedandpreviewedcanchange.

3.4MediaFilesandtheLibrary

UsingXBMC,youcanviewfilesfromUSBdevices(suchasmemorysticksandharddrives)oroveryourlocalnetwork.

Inadditiontobrowsingforfileseachtimeyouwanttoplaysomething,youcanadddevicesandnetworkfolderstoyourXBMClibrary.Thelibraryisalistofallofthefilesthatyouhaveavailable,andusuallycontainsextrainformationsuchaspreviewimagesanddescriptions.

Notethatevenifyouaddafiletoyourlibrary,itisstillstoredontheoriginaldeviceandwillnotbeavailableifthatdeviceisunpluggedorturnedoff.

PlayingMediaFilesfromUSBDevicesKeepingyourmediafilesonUSBstoragedevicesmeansthatyouarenottakingupspaceontheSDcardusedtorunXBMC.AndyoucanremoveUSBdevicesatanytimemakingthisaconvenientwayoftransferringfilesfromyourPCtobeplayedonyourmediabox.

Toplayafilewithoutaddingittoyourlibrary:

1.InserttheUSBdeviceintoafreeUSBslotonthePiorUSBhub.YoucandothiswhenthePiisonandrunningXBMC.

2.OntheXBMCHomescreen,pointtoVideosandthenclickFiles.3.ClicktheUSBdevicethatcontainsthefileyouwanttoplay.4.Browsetothefileandthenclickit.

AddingFilestoyourLibraryYourXBMClibraryismadeupofalistofsources,andinformationaboutthemediafilesthatyouhaveonyoursystem.AsourceisXBMCstermforafilepaththatitremembersbetweensessions,andthatitassociateswithaparticulartypeofcontent(forexample,amovie).WhenXBMCupdatesyourlibrary,itopenseachsourcefolderandexaminesallofthecompatiblemediafilesinside.

Duringthisprocess,XBMCrunsspecialprogramscalledscrapers.Theseadd-onsfindtheinformationaboutthefilesinyourlibraryandforthistowork,thefilenamesofmoviesandTVshowsthatyouwanttoaddmustfollowasetpattern.Ifthescrapercannotidentifythefilefromthefilename,XBMCwillnotaddthefiletoyourlibrary.

Theinstructionsbelowareanexampletogetyoustarted;formoredetailedinformation,seehttp://wiki.xbmc.org/index.php?title=Naming_video_files

IfyourUSBdevicecontainsmoviefilesandTVshows,createtwosubfoldersonthedeviceanduseoneformovies,andtheotherfortheTVshowepisodes.

Whennamingmoviefiles,usethepattern:Title(Year).extForexample:HouseOnHauntedHill(1999).mp4ToaddthemoviesfolderontheUSBdeviceasasource,andloadthefilesintoyourlibrary:

1.InserttheUSBdeviceintoafreeUSBslotonthePiorUSBhub.YoucandothiswhenthePiisonandrunningXBMC.

2.OntheXBMCHomescreen,pointtoVideosandthenclickFiles.

3.ClickAddVideosandthenclickBrowse.4.ClickRootfilesystem.

5.Clickmedia,andthenclickthenameoftheUSBdevice.

6.Clickthemoviesfolder,andthenclickOK.7.ClickOK.

8.FromtheThisdirectorycontainslist,select(Movies).

9.UnderChooseaScraper,clickTheMovieDatabase(oranotherscraperifyouhavealreadyinstalledone).

10.ClickOK.11.Ifyouareaskedwhetheryouwanttorefreshinfoforallitems,clickYes.IfTheMovieDatabasescrapercannotfindyourmovieinitslistings,XBMCwillnotaddthefiletoyourlibrary.Thereareotherscrapersavailableandyoucaninstalltheminsection3.6Add-onsonpage65.

ToaddTVshowstoyourlibrary,itisadvisabletocreateadirectorystructureinsidetheTVshowfolderontheUSBdevice.

CreateafolderforeachTVseries.Forexample,createafoldercalledTheAddamsFamily.Thencreatesubfoldersinsidethatforeachseason.Forexample,TheAddamsFamily/Season1andTheAddamsFamily/Season2.

Placethevideofilesforeachseasoninthecorrectsubfolder,andnameeachfilewiththepattern:AnythingIncludingSpaces_sXXeYY.ext.ReplaceXXwiththeseasonnumber,andYYwiththeepisodenumber.Forexample:TheAddamsFamily_s01e01.mp4

ToaddtheTVshowsfolderontheUSBdeviceasasource,andloadthefilesintoyourlibrary:

1.InserttheUSBdeviceintoafreeUSBslotonthePiorUSBhub.YoucandothiswhenthePiisonandrunningXBMC.

2.OntheXBMCHomescreen,pointtoVideosandthenclickFiles.

3.ClickAddVideosandthenclickBrowse.4.ClickRootfilesystem.

5.Clickmedia,andthenclickthenameoftheUSBdevice.

6.ClicktheTVshowsfolder,andthenclickOK.7.ClickOK.

8.FromtheThisdirectorycontainslist,select(TVShows).

9.UnderChooseaScraper,clickTheTVDB(oranotherscraperifyouhavealreadyinstalledone).10.ClickOK.

11.Ifyouareaskedwhetheryouwanttorefreshinfoforallitems,clickYes.Ifthescrapercannotfindyourfileinitslistings,XBMCwillnotaddthefiletoyourlibrary.ThereareotherscrapersavailableandyoucaninstalltheseusingtheAdd-onsmenu.

Playingandaddingmusicfilestoyourlibraryworksinthesameway.OntheHomescreen,pointtoMusicandthenclickFiles.

RemovingUSBDevicesMakesurethatyouproperlyejectUSBdevicesfromthesystem.ThisprocessstopsXBMCfromreadingorwritingtothedevicewhileyouunplugit,andensuresthatallofthechangesthatneedtobemadetothefilesystemarecompleted.

TosafelyremoveaUSBdevice:1.OntheXBMCHomescreen,pointtoVideosandthenclickFiles.2.Right-clickthedevice,andthenclickRemovesafely.3.RemovetheUSBdevicefromtheUSBsocket.

IftheUSBdevicecontainsthefilesforitemsinyourlibrary,thoseitemswillbeunavailableuntilyouplugthedevicebackintoyourPi.

PlayingVideosfromYourLibraryOnceyouhaveaddedsomevideostoyourlibrary,youcanaccessthemfromtheXBMChomescreen.Toplayamovie,either:

OntheXBMCHomescreen,pointtoMovies,andthenclickthepreviewofthefilethatyouwanttoplay;orOntheXBMCHomescreen,clickMoviestoloadthemoviebrowser.

Ifyouusethemoviebrowser,clickthenameofamovietostartplaying,orright-clickthemovieandthenclickMovieinformationtobringupawindowcontainingalltheinformationthatthescrapercouldfindoutaboutthatfile.

Figure3.ThemovieinformationdisplayToplayaTVshow,either:

OntheXBMCHomescreen,pointtoTVShows,andthenclickthepreviewofthefilethatyouwanttoplay;or

OntheXBMCHomescreen,clickTVShowstoloadtheshowbrowser.

IfyouusetheTVshowbrowser,clickthenameofaseriestoloadtheepisodesorright-clickitandthenclickTVshowinformationtoviewthedetailsofthatseries.Clickanepisodetostartplaying,orright-clicktheepisodeandthenclickEpisodeinformationtobringupawindowcontainingalltheinformationthatthescrapercouldfindoutaboutthatparticularepisode.

3.5NetworkDevicesandOtherComputers

ConnectingtoSMBSharesServermessageblock(SMB)isanetworkingprotocolforsharingprinters,files,andfoldersbetweendevicesonalocalnetwork.Itisawell-establishedsystem,andsupportforitisbuilt-inonmostpopularoperatingsystems.UsingSMB,XBMCcanaccessfoldersonyourWindows,MacOSX,orLinuxPCsasiftheywerelocaldevices.

SMBsharesmustbeaddedtoXBMCassources,andsoitisusuallyusefultohaveyourmovies,TVshows,music,andpicturesseparatedintodifferentfolders.

TocreateanewsharedfolderonWindows(8/7/Vista/XP):1.PresstheWindowslogokey+R.TypeexplorerandthenpressEnter.

2.BrowsetoalocationonyourPCthateitheralluserscanaccess(suchasanextraharddrivepartition)orthatbelongstotheuserthatiscurrentlyloggedin.

3.Right-clickintherightpanel,pointtoNew,andthenclickFolder.4.Typeaname(forexample,Videos)andthenpressEnter.5.Right-clickthefolder,andthenclickProperties.6.OntheSharingtab,underNetworkFileandFolderSharing,clickShare.

7.IntheFileSharingwindow,clickShare.8.ClickClose.

9.InWindowsExplorer,double-clickthefolder.Right-clickintherightpanel,pointtoNewandthenclickFolder.Typeaname(forexample,Movies)andthenpressEnter.

10.Right-clickintherightpanel,pointtoNewandthenclickFolder.Typeaname(forexample,TVShows)andthenpressEnter.

11.Copyormoveyourmoviefilesintothemoviesfolder,andTVshowepisodesintotheTVshowsfolder.

TocreateanewsharedfolderonMacOSX(10.5orlater)usingGuestSharing:

1.Onthedock,clickFinder.2.Browsetoyourhomefolder.

3.OntheFilemenu,clickNewFolder.Typeaname(forexample,Videos)andpressEnter.4.Clickthisfolder.5.OntheFilemenu,clickNewFolder.Typeaname(forexample,Movies)andpressEnter.6.OntheFilemenu,clickNewFolder.Typeaname(forexample,TVShows)andpressEnter.

7.Copyormoveyourmoviefilesintothemoviesfolder,andTVshowepisodesintotheTVshowsfolder.

8.OntheApplemenu,clickSystemPreferences.9.ClickSharing.10.ClicktheboxnexttoFileSharing.

11.BelowtheSharedFolderslist,clickthe+button.12.Browsetoyourvideosfolder,double-clickit,andthenclickAdd.13.NexttoEveryone,clickReadOnly,andthenclickRead&Write.14.ClickOptions.15.ClicktheboxnexttoSharefilesandfoldersusingSMB.16.ClickDone.NowthatsharingisenabledandyouhavefoldersthatyouwantXBMCtolookat,addtheSMBshareasanXBMCvideosource:

1.OntheXBMCHomescreen,clickVideos.2.ClickAddVideosandthenclickBrowse.3.ClickAddnetworklocation14.IntheProtocollist,clickWindowsnetwork(SMB).5.NexttoServer,clickBrowse.

6.Clickthenameofyourworkgroup,andthenclickthenameoftheWindowsPCorMac.

7.IntheUsernamebox,typeyourWindowsusername(orthenameofauseraccountthathasaccesstothesharedfolder.)DonotenterausernameifyouareusingGuestSharingonMacOSX10.5orlater.

8.InthePasswordbox,typethepasswordforthatuser.9.ClickOK.10.Clickthenewnetworklocation.Thisissmb://,followedbythenameofyourPCorMac.

11.Browsetoyourmoviesfolderandthenclickit.12.ClickOK.13.ClickOK.

14.FromtheThisdirectorycontainslist,select(Movies).

15.UnderChooseaScraper,clickTheMovieDatabase(oranotherscraperifyouhavealreadyinstalledone).

16.ClickOK.17.Ifyouareaskedwhetheryouwanttorefreshinfoforallitems,clickYes.

ToaddtheTVshowsfolder,repeatthisprocessbutselect(TVShows)fromtheThisdirectorycontainslistandTheTVDBscraperfromtheChooseaScraperlist.1.TheAddnetworklocationoptionallowsformorecontrolovertheusernameandpasswordthantheWindowsnetwork(SMB)option.

XBMCsscraperswillattempttoaddthefilesfromyoursourcestoyourlibrary.ThismeansthatthefilesinyoursharedfoldermustfollowthenamingconventionsdescribedinAddingFilestoyourLibraryonpage54.

Ifthescrapercannotfindinformationaboutthefile,XBMCdoesnotaddthefiletoyourlibrary.However,youcanstillusetheVideosfilebrowsertoaccessanyfilesthatwerenotadded.

ThemostcommoncauseofproblemswhencreatingSMBsharesandaddingthemto

XBMCisuserpermissions.Ifyoucannotconnecttoyourshare,orcannotseethefilesinsideit,thenchecktheuseraccountpermissionsonyourPCorMac.Ifnecessary,youcandeleteasourceandstartover.

Todeleteasource:1.OntheXBMCHomescreen,pointtoVideos,andthenclickFiles.2.Right-clickasource,andthenclickRemovesource.

ConnectingtoUPnPDevicesUniversalplugandplay(UPnP)isacollectionofnetworkingprotocolsthatallowsdevicesonalocalnetworktofindeachother,tofindoutwhattypeofservicesandfilesotherdevicesoffer,andtosharethosefiles.

YoucansetupyourPCorMacsothatXBMContheRaspberryPicanplaythemediafilesfromit.OnMacOSXandLinuxmachines,youwillneedtoinstallandconfigureaUPnPmediaserver,suchasMediaTomb(http://www.mediatomb.cc).MicrosoftWindowshasabuilt-inUPnPserver,butthisisusuallydisabledwhentheoperatingsystemisinstalled.

ToenabletheUPnPserveronWindows(8/7/Vista):

1.PresstheWindowslogokey+R.Typecontrol.exe/nameMicrosoft.NetworkAndSharingCenterandthenpressEnter.

2.OnWindows8/7:clickChangeadvancedsharingsettings.OnWindowsVista:clickthearrowtotherightofNetworkDiscovery.

3.ClicktheboxnexttoTurnonnetworkdiscovery,andthenclickSavechanges(orApplyonVista).ToenabletheUPnPserveronWindowsXP:1.PresstheWindowslogokey+R.Typeappwiz.cplandthenpressEnter.

2.ClickAdd/RemoveWindowsComponents.3.ClickNetworkingServices,thenclickDetails.

4.Ifitisnotselected,clicktheboxnexttoInternetGatewayDeviceDiscoveryandControlClient.5.Ifitisnotselected,clicktheboxnexttoUPnPUserInterface.

6.ClickOK.7.ClickNext.

8.PresstheWindowslogokey+R.Typeservices.mscandthenpressEnter.9.Double-clickSSDPDiscoveryService.10.OntheGeneraltab,intheStartuptypelist,clickAutomatic.11.ClickOK.12.RestartyourPC.

UPnPdevicesandtheirfoldersshouldbeaddedtoXBMCassources.AlthoughfilesstoredonthesetypesofdevicescannotbeaddedtotheXBMClibrary,theycanstillbeaccessedusingthevideosandmusicfilebrowsers.

Toaddavideosource:

1.OntheXBMCHomescreen,clickVideos.2.ClickAddVideosandthenclickBrowse.

3.ClickUPnPDevices,andthenclickthenameofyourdevice.

4.Browseintoafolder,ifyouwanttoadditanditssubfoldersonly.5.ClickOK.6.ClickOK.Toaddamusicsource:

1.OntheXBMCHomescreen,clickMusic.2.ClickAddMusicandthenclickBrowse.

3.ClickUPnPDevices,andthenclickthenameofyourdevice.4.Browseintoafolder,ifyouwanttoadditanditssubfoldersonly.5.ClickOK.6.ClickOK.

IfyourUPnPdeviceappearsintheUPnPDeviceslistbutyoucannotopenittobrowseitscontent,thereareafewthingstocheck:

IfyouarerunningafirewallonaWindowsPCwithUPnPenabled,youmayneedtocreateanexceptionfortheWindowsMediaPlayerNetworkSharingServiceorUPnPFramework.

OnWindows,placeyourvideoandmusicfilesintheVideosandMusicfoldersoftheuserthatiscurrentlylogged-in.CheckthattheWindowsuserEveryoneisabletoreadfromthosefolders.

Checkthatyournetworkrouterallowsdevicesonyournetworktotalktoeachother.Updateyouroperatingsystemtothelatestversion.UpdateXBMCtothelatestversion.

3.6Add-ons

Add-onsextendthefunctionalityofXBMCinuniqueways,andtherearemanyadd-onsavailable.Thesevaryfrommakingsmallchangestotheinterface,tolettingyouwatchliveTVandstreamvideosovertheInternet.

Todownloadandinstallanadd-on:1.OntheXBMCHomescreen,pointtoSystem,andthenclickSettings.2.ClickAdd-ons.3.ClickGetAdd-ons,andthenclickXBMC.orgAddons.

4.Clickthetypeofadd-onthatyouwanttoinstall.Forexample,VideoAdd-onsaddnewwaysofwatchingvideos.

5.Inthelistofavailableadd-ons,clickonetobringupadescription.6.ClickInstalltodownloadandinstalltheadd-on.

InstallingMovieInformationAdd-onsMovieinformationadd-onsareatypeofextensionforfindinginformationaboutthevideofilesinyourlibrary.Bydefault,thescraperthatfindsinformationaboutyourmoviefilesusesTheMovieDatabasewebsite.Toinstalladifferentmoviescraper,andconfigureavideosourcetouseit:

1.OntheXBMCHomescreen,pointtoSystem,andthenclickSettings.2.ClickAdd-ons.3.ClickGetAdd-ons,andthenclickXBMC.orgAddons.4.ClickMovieinformation,andthenclickUniversalMovieScraper.

5.ClickInstall.6.OntheXBMCHomescreen,pointtoVideos,andthenclickFiles.

7.Right-clickyourvideosource,andthenclickChangecontent.8.UnderChooseaScraper,clickUniversalMovieScraper.9.ClickOK.10.Ifyouareaskedwhetheryouwanttorefreshinfoforallitems,clickYes.

InstallingProgramAdd-onsProgramadd-onsarepowerfulextensionsthatincludeprogramsforaccessingthewebandsocialmediasites,clientsforfilesharingandfilehostingservices,backuputilities,andeventorrentclients.

Toopenthelistofprogramadd-ons:1.OntheXBMCHomescreen,pointtoSystem,andthenclickSettings.2.ClickAdd-ons.3.ClickGetAdd-ons,andthenclickXBMC.orgAddons.4.ClickProgramAdd-ons.

3.7RemoteControls

XBMChasabuilt-inwebserverthatyoucanusetocontrolit.ThisturnsanydevicewithawebbrowserintoaremotecontrolforXBMC.Therearealsoseveralremotecontrolappsavailableforsmartphonesandtablets.TheseappsusuallytalktoXBMCusingthewebserver.

Toenablethewebserver:

1.OntheXBMCHomescreen,clickSystem.2.ClickServices.3.ClickWebserver.

4.EnsureAllowcontrolofXBMCoverHTTPisselected.5.InthePortbox,typeaportnumber.Thisnumbermustbeover1024.6.IntheUsernamebox,typexbmc.7.InthePasswordbox,typeapasswordthatyouwanttouse.8.PresstheBackorHomebuttonstoleavethesystemsettings.

ToconnecttoXBMC,youneedtoknowitsIPaddressonyourlocalnetwork.TheIPaddressisshownintheSummaryandNetworktabsoftheSysteminfoscreen.Tofindthis:

OntheXBMCHomescreen,pointtoSystem,andthenclickSysteminfo.

Testtheremotecontrolfeaturebyopeningawebbrowseronadeviceonyourlocalnetwork.Intheaddressbar,typehttp://followedbytheIPaddressoftheRaspberryPi,thenacolon,andthentheportnumberthatissetintheXBMCsettings.

Forexample,toaccesstheremotecontrolwebinterfaceoverport8080onaPiwiththeIPaddress192.168.0.9,typehttp://192.168.0.9:8080

Loginwiththeusernamexbmc,andthepasswordthatyousetintheXBMCsettings.

IfyoucannotconnecttoXBMC,firstcheckthattheRaspberryPihasanactivenetworkconnectionandthenverifythattheconnectionsettingsyouareusingmatchthosethatyouenteredintheXBMCsettings.Ifyoustillcannotconnect,tryadifferentportnumber.

Figure4.TheXBMCwebinterface

Touseasmartphoneortabletapp,youwillneedthesamedetailsthatyouusedtoaccesstheremotecontrolwithawebbrowser.AppsareavailableforiOS,Android,andWindowsPhone.However,theOfficialXBMCRemoteappisonlyavailableforiOSandAndroiddevices.

Atthetimeofwriting,thecurrentversionoftheOfficialXBMCRemotehasafewproblems.Butdevelopersupdateappsextremelyfrequently,andtheissuesmaybefixedbythetimeyoureadthis.Ifyoucannotgettheofficialappworking,searchyourdevicesappstoreandyouwillfindmanyotherstotry.

4ProgrammingwithScratchScratchisavisualprogramminglanguagethathelpsteachtheconceptsofprogrammingtopeoplewhohaveneverworkedwithtraditionalprogramminglanguages.Itisaimedprimarilyatpeoplewhowanttolearntobuildsmallgames.However,thecombinationofitssimpleinterfaceandrichfeaturesetalsomakeitusefulforpresentations,simulations,andprototypesofsoftwarethatwillbeimplementedinotherlanguages.ThecurrentversionofScratchfortheRaspberryPiis1.4.Version2.0ofScratchisavailableonmanyplatforms,however,itisnotcompatiblewiththePi.

4.1TheUserInterface

TostartScratchonRaspbian:Onthedesktop,double-clickScratch;orOntheLXDEpanel,clicktheMenubutton,pointtoProgramming,andthenclickScratch.TheScratchwindowisdividedintoseveraldistinctareas:

Figure1.ScratchonRaspbian1CursorTools.Thesebuttonsareforduplicating,deleting,growing,andshrinkingthespritesonthestage.Clickthecursortool,andthenclickaspritetoactivatethefunction.

2Menu.3BlocksPalette.

4ScriptsArea.ThisiswhereyoucombineblockstocontrolthespritethatisselectedintheSpriteList.5SpriteList.Allofthespritesinyourprojectareshownhere.Clickaspritetoshowthescriptsthatyouhaveaddedforaparticularsprite.6Stage.Thisiswhereyourspritesmoveandinteractwitheachother.

ThekeyconceptbehindScratchisthateverythingyouneedtomove,animate,orcontrolisasprite.Eachspriteisacollectionofimagesandscripts,andisindependentofalloftheothers.YoucombinethecoloredblocksfromtheBlocksPalettetosetthebehaviorofaspecificsprite.

OpeningandSavingProjectsScratchprojectsaresavedinaspecialfileformatthatusestheextension.sb.ThesefilescontainallofthegraphicsandsoundfilesthatyouimportintoScratch,andallofthescriptsthatyoucreate.

Tosaveaprojecttoanewfile:1.OntheMenubar,clickFile,andthenclickSaveAs2.IntheNewFilenamebox,typeanameforyourprojectandthenclickOK.

Ifyouhavepreviouslysavedyourprojectandyouwanttosaveitagain:OntheMenubar,clicktheSavethisprojectbutton(itlookslikeafloppydisk);orOntheMenubar,clickFile,andthenclickSave.Toclosethecurrentprojectandopenanother:1.OntheMenubar,clickFile,andthenclickOpen2.Browsetothefilethatyouwanttoopen,clickit,andthenclickOK.

UsingtheStageAllofthespritesinyourprojectappearontheStage,andthisiswhereallofyouractionsandscriptstakeplace.AspritecannotcompletelyleavetheStage,however,youcanhidespritesthatarenotneededatspecificpartsofyourproject.

InScratch,theStageisalways480stepswideand360stepstall.Itneverchangessize,itnevermoves,anditneverresets.Forexample,onceaspritemovesitremainsatthatpositiononthestageuntilanotherscriptmovesit.Thepositionofeachspriteisdescribedwithacoordinatetwonumbers,onethatrepresentsthehorizontalposition(x)andonethatrepresentstheverticalposition(y).Thetop-leftoftheStageis-240,180,thebottomrightoftheStageis240,-180,andthismakesthecenteroftheStage0,0.

IntheSpriteList,thereisanimagefortheStage.Ifyouclickthis,youcanaddblockstotheStageitself.WhentheStageisselected,thetabsatthetopoftheScriptsAreachange.

YoucanchangethebackgroundoftheStagefromtheBackgroundstab.YoucaneitherusethePaintEditortodrawanewbackground(ThePaintEditorisdescribedinsection4.9ThePaintEditoronpage89),orimportgraphicfiles.Importedgraphicsshouldbe480pixelswideand360pixelstall,orScratchwillpositiontheminthecenteroftheStagesurroundedbybordersofthecurrentbackgroundcolor.

YoucanhavemultiplebackgroundsinaScratchproject,butonlyonecanbevisibleatatime.YoucannotmovebackgroundsinScratch,soifyouwantareasofthebackgroundtomovethenyouhavetocreatethemassprites.

BuildingandRunningScriptsThissectiondescribeshowtoworkwithblocksfromtheBlocksPalettetocreatescriptssequencesofblocks.Eachsprite(andtheStageitself)cancontainmanyscripts.

ToattachablocktoaspriteortheStageitself,selectitintheSpriteListandthendragblocksfromtheBlocksPalettetotheScriptsArea.Forexample:

1.IntheSpriteList,clickStage.2.IntheBlocksPalette,clickControl.

3.Clicktheblockwhenclickedand,whileholdingthemousebutton,dragtheblockovertotheScriptsArea.Releasethemousebutton.

4.IntheBlocksPalette,clickLooks.

5.Dragtheblockchangecoloreffectby25totheScriptsAreaandunderneaththeotherblock.Thewhitelineindicatesthatthisblockwillsnaptogetherwiththeoneaboveit.Releasethemousebutton.

6.IntheScriptsArea,ontheblockchangecoloreffectby25,clickcolor,andthenclickbrightness.7.Ontheblockchangebrightnesseffectby25clickthewhiteboxthat

contains25.Changethisto-25.8.IntheBlocksPalette,clickControl.

9.Dragtheblockwait1secstotheScriptsAreaandsnapittothebottomoftheblockchangebrightnesseffectby-25.

10.Ontheblockwait1secs,clickthewhiteboxthatcontains1.Changethisto0.5.11.IntheBlocksPalette,clickLooks.

12.Dragtheblockchangecoloreffectby25totheScriptsAreaandsnapittothebottomofthewaitblock.

13.Ontheblockchangecoloreffectby25,clickcolor,andthenclickbrightness.Figure2.Ashortscript

AbovetheStage,therearetwobuttons:thegreenflagbuttonstartsallscriptsintheproject,andtheredoctagonstopsallofthescripts.

Thefirstblockthatisinthescript,whenclicked,statesthatthescriptshouldrunwhenthegreenflagbuttonabovetheStageisclicked.Clickthegreenflagbuttonnowandyoushouldseethatthebackgroundbrieflychangescolor.ToDoThisRunascript(fortesting)IntheScriptsArea,double-clickanyoftheblocksinthescript.

InsertablockaboveanexistingblockIntheBlocksPalette,dragablockovertotheScriptsAreaandoverthetopofanexistingblock.Thewhitelineindicateswheretheblockwillbeinserted.

Detachablock(andanyblocksthatfollowit)fromascriptIntheScriptsArea,clicktheblockanddragitawayfromtheblockaboveit.Alloftheblocksbelowtheselectedblockwillmovewithit.

Removeablock,aseriesofconnectedblocks,orascriptfromtheproject

IntheScriptsArea,clickthefirstblockintheseriesthatyouwanttoremoveanddragitovertotheBlocksPalette.

ToDoThis

Duplicateablock,aseriesofconnectedblocks,orascriptIntheScriptsArea,right-clickthefirstblockintheseriesthatyouwanttocopy,clickduplicate,andthenclickintheScriptsAreatopositionthenewblocks.

FittingtheBlocksTogetherScratchusesthecolorandshapeofblockstoindicatehowtheycanbeconnectedtoeachother.Blockswithacurvedtop,suchasthewhenclickedblock,arethestartofascriptandcanonlyhaveblocksconnectedunderneaththem.Figure3.Youcanonlysnapinblocksbelowthisone,notabove.

Anotchinthetopofablockindicatesthatitcanbeattachedtoblocksaboveit.Atabonthebottomindicatesthatyoucansnapotherblocksintopositionbelowit.Figure4.Ablockthatallowsotherblockstobeconnectedontop,orunderneath.

Aneight-sidedwhiteboxintheblockmeansthatyoucantypenumbersinthere,butalsothatyoucanaddvariablesandblocksfromtheOperatorssectionoftheBlocksPalette.

Touseanoperatororvariableblockinsteadofanumber:Draganeight-sidedblockfromtheBlocksPalette,intotheScriptsArea,andoverthewhitebox.

Someblockshavesquareboxesthatyoucantypein.Theseacceptnumbers,strings(sequencesofcharacters),variables,andeight-sidedoperatorblocks.

BlockslikeifintheControlsectionoftheBlocksPalettehavespacesforsix-sidedblocks.Six-sidedblocksrepresentthevaluesYesorNo,orTrueorFalse.Thesearedescribedinmoredetailinsection4.4Decisionsonpage82.

4.2Sprites

InScratch,youwillspendthemajorityofyourtimemovingandchangingtheappearanceofspritesinresponsetokeypresses.

AddingandRemovingaSpriteToaddaspritetothecurrentprojectandmakeitappearontheStage:

1.AbovetheSpriteList,nexttoNewSprite,clicktheChoosenewspritefromfilebutton.Thisisthesecondbuttoninthatarea.

2.IntheNewSpritewindow,browsetoaspritethatyouwanttoadd,clickitandthenclickOK.3.OntheStage,clickanddragthespritetoanewlocation.

Ifaspriteisthewrongsize,clickontheShrinkspriteorGrowspritebuttonintheCursorToolsareaandthenclickonthesprite:

Todeleteasprite:IntheSpriteList,right-clickaspriteandthenclickdelete.

CreatingaNewSpriteTherearetwowaysofcreatingnewspritesinScratch:youcanusethebuilt-indrawingtoolstopaintanewsprite,oryoucanimportgraphicfilesfromothertoolslikeAdobePhotoshopandKolourPaint.

Ineithercase:AbovetheSpritesList,nexttoNewSprite,clickthePaintnewspritebutton.Thisisthefirstbuttoninthatarea.

Ifyouwanttoimportagraphicfile,clickImportinthePaintEditor.Theeditorisdescribedinsection4.9ThePaintEditoronpage89.

UnderstandingCostumesInmostprojects,andespeciallyingames,youwillneedtochangetheappearanceofyourspritesastheprojectisrunning.Thesecanbeframesofananimation,asisthecasewhenthespriteiswalking.Orthesecanbealternativeversionsofthespritethatusedifferentcolorsorholddifferentweapons.

InScratch,variationsofaspriteareknownascostumes.Ifyoucreateanewsprite,itwillonlyhaveonecostume.Toaddanothercostumetotheselectedsprite:

1.IntheScriptsArea,clickCostumes.2.Ifyouwanttodrawanewspriteusingthebuilt-inPaintEditor,clickPaint.3.Ifyouwanttoimportagraphicfiletouseasacostume,clickImport.ToDoThis

SetthecurrentcostumeofaspritefromtheScriptsArea(notfromascript)

IntheScriptsArea,clickCostumes,andthenclicktheimageofthecostume.

RenameacostumeIntheScriptsArea,clickCostumes.

Clickthetextboxthatcontainsthecurrentname(forexample,costume1)andthentypeanewname.

Duplicateacostume

IntheScriptsArea,clickCostumes.Nexttothecostumethatyouwanttoduplicate,clickCopy.

ToDoThisDeleteacostumeIntheScriptsArea,clickCostumes.Nexttothecostumethatyouwanttoremove,clickx.Editacostumeusingthebuilt-inPaintEditor

IntheScriptsArea,clickCostumes.Nexttothecostumethatyouwanttochange,clickEdit.

ScriptingYourSpritesMotionblockssetthepositionofsprites.OntheStageyoucanclickanddragspriteswhereyouwantthem,buttomovethemfromscripts(forexample,inresponsetotheuserpressinganarrowkey)youneedtouseoneofthemotionblocks.Theseare:BlockDescriptionmove?stepsMovesaspriteanumberofstepsinthedirectionitiscurrentlypointing.

turn(clockwise)?degreesRotatesaspriteanumberofdegreesinaclockwisedirection.

turn(counterclockwise)?degreesRotatesaspriteanumberofdegreesinancounter-clockwisedirection.

pointindirection?Rotatesorflipsaspritetofacethespecifieddirection.pointtowards?Rotatesorflipsaspritetofacethemousepointeroranothersprite.gotox:?y:?Setsthepositionofasprite.goto?Movesaspritetothelocationofthemousepointeroranothersprite.

glide?secstox:?y:?Animatesthemovementofaspritetothespecifiedlocation.

changexby?Movesaspritehorizontallybythenumberofstepsspecified.Thisnumbercanbenegative.setxto?Movesaspritehorizontallytothespecifiedposition.changeyby?Movesaspriteverticallybythenumberofsteps

specified.Thisnumbercanbenegative.setyto?Movesaspriteverticallytothespecifiedposition.

ifonedge,bounceChangesthedirectionofaspritewhenitreachestheedgeoftheStage.

Eachspritealsohasthreevariablesthatarechangedbythemotionblocks.Thesecanbeusedindecision-makingandarithmeticblocks.VariableDescriptionxpositionThehorizontalpositionofthespriteontheStage.ypositionTheverticalpositionofthespriteontheStage.directionThedirectionthatthespriteiscurrentlyfacing.

WhenspritesareaddedtotheStage,Scratchassumesthattheyfacetotheright.Whenyouchangethedirectionthataspritefaces,Scratchrotatesthesprite.TotellScratchthatitshouldflipaspriteandnotrotateit:

1.IntheSpriteList,clickasprite.

2.AtthetopoftheScriptsArea,nexttothepictureofthesprite,clicktheonlyfaceleft-rightbutton.Thisisthesecondbuttonofthethreethatarearrangedvertically.

TheLooksblocksintheBlocksPalettechangetheappearanceofspritesontheStage.Someoftheseblockschangeaspritescostume,andsomeofthemapplyeffects(suchasfades).switchtocostume?Setsthecostumedisplayedforthissprite.nextcostumeChangestothenextcostume.Ifthecurrentcostumeisthelastone,thefirstcostumewillbeusedinstead.say?for?secsDisplaysaspeechbubblenexttothesprite.say?Displaysaspeechbubblenexttothesprite.Thisbubbleremainsuntilyouuseasayblockwithnotext.think?for?secsDisplaysathoughtbubblenexttothesprite.think?Displaysathoughtbubblenexttothesprite.Thisbubbleremainsuntilyouuseathinkblockwithnotext.

change?effectby?Seebelow.set?effectto?Seebelow.cleargraphiceffectsSeebelow.changesizeby?Growsorshrinksaspritebytheamountspecified.setsizeto?%Growsorshrinksaspritebysettingitssize.Thisisapercentageofthesizeofthegraphicusedtocreatethesprite,anditcanbegreaterthan100%.showShowsthespriteontheStageifitiscurrentlyhidden.hideHidesaspriteifitiscurrentlyshown.gotofrontMovesaspriteinfrontofallothers.goback?layersMovesaspritebehindothersprites.Therearesevendifferenteffectsthatyoucanaddtosprites:EffectDescriptioncolorChangesthecolor(hue)ofasprite.fisheyeDistortsthesprite.EffectDescriptionwhirlDistortsthespriteintoaswirlarounditscenterpoint.pixelateMakesthespriteappeartobemadeupoflargerpixels.mosaicMakesthespriteappeartobemadeupsmallerclonesofitself.

brightnessWhenusedwithpositivenumbers,thisincreasesthebrightness(howclosethecolorsaretowhite).Whenusedwithnegativenumbers,thisdecreasesthebrightness(howclosethecolorsaretoblack).

ghostMakesthespritetranslucent(sothatotherspritescanbeseenthroughit)orcompletelytransparent(thespriteisinvisible).

Youcontroltheseeffectsusingthreeblocks:Tosetaneffecttoaspecificvalue,usetheset?effectto?block.

Toincreaseordecreasetheamountofaneffectthatisappliedtoasprite,usethechange?effectby?block.

Toremoveallactiveeffectsfromasprite,usethecleargraphicseffectsblock.Allspriteshavetwovariablesrelatedtotheirappearance:VariableDescriptioncostume#Thenumberofthecostumethatiscurrentlydisplayedforthissprite.sizeThesizeofaspriteontheStage.Thisisapercentageofthesizeofthegraphicusedtocreatethesprite,anditcanbegreaterthan100%.YoucanchoosewhetherScratchshoulddisplaythesevariablesontheStage.Toshowthevalueofavariable:IntheBlocksPalette,clicktheboxnexttothevariablename.ClicktheboxagaintoremovethevariablefromtheStage.

4.3ArithmeticandVariables

IntheOperatorssectionofBlocksPalette,thereareeightblocksthatyoucanusetoperformbasicmathoperations,suchasaddingtwonumberstogether.Theseblocksareeight-sided,greenblocksandtheyfitintoanyotherblockthatacceptsanumber.BlockDescription

?+?Addstwonumberstogether.?-?Subtractsthesecondnumberfromthefirst.?*?Multipliestwonumberstogether.?/?Dividesthefirstnumberbythesecond.

pickrandom?to?Picksarandomnumberbetweenthefirstnumberandthesecondnumber.

?mod?Performsmodulararithmeticthefirstnumberwrapsaroundifitreachesthevalueofthesecondnumber.

round?Roundsthespecifiednumbertothenearestwholenumber.?of?Selectfromarangeofadditionalmathfunctions.

Youcanusearithmeticoperatorblocksasinputstootherarithmeticblocks.Forexample,theexpression1+((14/3)x3.14)canbecreatedwiththreeblocks:Figure5.Nestedoperatorblocks

CreatingandUsingVariablesAvariableisanamedareaofthecomputersmemoryinwhichyoucanstorepiecesofdata.

TocreateavariableinScratch:

1.IntheBlocksPalette,clickVariables.2.ClickMakeaVariable.3.Typeanameforyourvariable.

4.Ifyouwantallspritestobeabletoaccessthevariable,clickthecirclenexttoForallsprites.5.Ifyouonlywantthisspritetobeabletoaccessthevariable,clickthecirclenexttoForthisspriteonly.6.ClickOK.

Whenyoucreateavariable,ScratchaddsablockforitintheVariablessectionoftheBlocksPalette.Theseorangevariableblockswillfitintoblocksthatacceptanumber.

TherearefourblocksintheVariablessectionoftheBlocksPaletteforworkingwithvariables:BlockDescription

set?to?Setsthevalueofavariable.change?by?Incrementsordecrementsavariable.showvariableAddsthespecifiedvariabletotheStage.hidevariableRemovestheselectedvariablefromtheStage.

4.4Decisions

Therearesixblocksthatyouusetocomparenumbersandmakedecisions.TheresultoftheseblocksisaBooleanvalueeithertrueorfalse..BlockDescription??Istrueifthefirstnumberislargerthanthesecond,orfalseifitisnot.?and?Istrueifthebothoftheattachedblocksaretrue,orfalseifeither(orboth)ofthemisfalse.?or?Istrueifeitherofthetwoattachedblocksistrue.Ifneitheraretrue,thenitreturnsfalse.not?Istrueiftheattachedblockisfalse,andfalseiftheattachedblockistrue.TwoblocksintheControlsectionoftheBlocksPaletteareusedwiththeBooleanoperatorblockstomakedecisions.BlockDescriptionif?Runstheblocksinsideit,iftheattachedBooleanoperatoristrue.

if?