CHAPTER 1

QuickstartTHISISACHAPTERfortheimpatientEvilGenius.YournewArduinoboardhasarrived,andyouareeagertohaveitdosomething.

So,withoutfurtherado

Powering UpWhenyoubuyanArduinoUnoorLeonardoboard,itisusuallypreinstalledwithasampleBlinkprogramthatwillmakethelittlebuiltinLEDflash.Figure11showsapairofArduinoboards.

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Figure11 ArduinosUnoandLeonardo.

Thelightemittingdiode(LED)markedLiswireduptooneofthedigitalinputoutputsocketsontheboard.Itisconnectedtodigitalpin13.Thisreallylimitspin13tobeingusedasanoutput,buttheLEDonlyusesasmallamountofcurrent,soyoucanstillconnectotherthingstothatconnector.

AllyouneedtodotogetyourArduinoupandrunningissupplyitwithsomepower.TheeasiestwaytodothisistopluginitintotheUniversalSerialBus(USB)portonyourcomputer.ForanArduinoUno,youwillneedatypeAtotypeBUSBlead.Thisisthesametypeofleadthatisnormallyusedtoconnectacomputertoaprinter.ForaLeonardo,youwillneedamicroUSBconnector.Youmaygetsomemessagesfromyouroperatingsystemaboutfindingnewdevicesorhardware.Ignorethesefornow.

Ifeverythingisworkingokay,theLEDshouldblinkonceeverytwoseconds.ThereasonthatnewArduinoboardshavethisBlinksketchalreadyinstalledistoverifythattheboardworks.ClickingtheResetbuttonshouldcausetheLEDtoflickermomentarily.Ifthisisthecase,buttheLEDdoesnotflash,thenitmayjustbethattheboardhasnotbeenprogrammedwiththeBlinksketchbutdonotdespair,asonceeverythingisinstalled,wearegoingtomodifyandinstallthatscriptanywayasourfirstproject.

Installing the SoftwareNowthatwehaveourArduinoworking,letsgetthesoftwareinstalledsothatwecanaltertheBlinkprogramandsenditdowntotheboard.Theexactproceduredependsonwhatoperatingsystemyouuseonyourcomputer.Butthebasicprincipleisthesameforall.

InstalltheArduinodevelopmentenvironment,whichistheprogramthatyourunonyourcomputerthatenablesyoutowritesketchesanddownloadthemtotheArduinoboard.

InstalltheUSBdriverthatallowsthecomputertotalktotheArduinosUSBport.Itusesthisforprogrammingandsendingmessages.

TheArduinowebsite(www.arduino.cc(http://www.arduino.cc))containsthe

latestversionofthesoftware.InthisbookwehaveusedArduino1.0.2.

Installation on Windows

TheinstructionsthatfollowareforinstallingonWindows7.TheapproachismuchthesameforVistaandXP.Theonlypartthatcanbealittledifficultisinstallingthedrivers.

FollowthedownloadlinkontheArduinohomepage(www.arduino.cc(http://www.arduino.cc)),andselectthedownloadfor

Windows.ThiswillstartthedownloadoftheZiparchivecontainingtheArduinosoftware,asshowninFigure12.Youmaywellbedownloadingamorerecentversionofthesoftwarethantheversion1.0.2shown(misleadingly,theArduinoteamhavenotgotaroundtorenamingtheZipfileyet).

Figure12 DownloadingtheArduinosoftwareforWindows.

TheArduinosoftwaredoesnotdistinguishbetweendifferentversionsofWindows.Thedownloadshouldworkforallversions,fromWindowsXPonward.ThefollowinginstructionsareforWindows7.

SelecttheSaveoptionfromthedialog,andsavetheZipfileontoyourdesktop.ThefoldercontainedintheZipfilewillbecomeyourmainArduinodirectory,sonowunzipitontoyourDesktop.Youcanmoveitsomewhereelselaterifyouwish.

YoucandothisinWindowsbyrightclickingtheZipfiletoshowthemenuinFigure13andselectingtheExtractAlloption.ThiswillopentheExtractionWizard,showninFigure14.

Figure13 TheExtractAllmenuoptioninWindows.

Figure14 ExtractingtheArduinofileinWindows.

ExtractthefilestoyourDesktop.

ThiswillcreateanewdirectoryforthisversionofArduino(inthiscase,1.0.2)onyourDesktop.Youcan,ifyouwish,havemultipleversionsofArduinoinstalledatthesametime,eachinitsownfolder.UpdatesofArduinoarefairlyinfrequentandhistoricallyhavealwayskeptprettygoodcompatibilitywithearlierversionsofthesoftware.Sounlessthereisanewfeatureofthesoftwarethatyouwanttouse,oryouhavebeenhavingproblems,itisbynomeansessentialtokeepupwiththelatestversion.

NowthatwehavegottheArduinofolderintherightplace,weneedtoinstalltheUSBdrivers.Ifyouhavenotalreadydoneso,plugyourLeonardoorUnointoyourcomputer.DependingonyourversionofWindows,theremaybesomehalfheartedattemptbytheoperatingsystemtoinstalldrivers.Justcancelthisattheearliestopportunityitisunlikelytowork.Instead,youneedtoopentheDeviceManager.ThisisaccessedindifferentwaysdependingonyourversionofWindows.InWindows7,youfirsthavetoopentheControlPanel,thenselecttheoptiontoviewIcons,andyoushouldfindtheDeviceManagerinthelist.

UnderthesectionOtherDevices,youshouldseeaniconforUnknownDevicewithalittleyellowwarningtrianglenexttoit.ThisisyourArduino(Figure15).

Figure15 TheWindowsDeviceManager.

RightclickontheUnknownDeviceandselecttheoptionUpdateDriverSoftware.YouwillthenbepromptedtoeitherSearchautomaticallyforupdateddriversoftwareorBrowsemycomputerfordriversoftware.Selecttheoptiontobrowseandnavigatetothearduino1.0.2windows\arduino1.0.2\drivers(Figure16).ChangetheversionnumbersifyouareusingadifferentversionofArduino.

Figure16 BrowsingfortheUSBdrivers.

ClickNext,andyoumaygetasecuritywarningifso,allowthesoftwaretobeinstalled.Oncethesoftwarehasbeeninstalled,youwillgetaconfirmationmessageliketheoneinFigure17.AlthoughthemessagewillbedifferentforaLeonardo,theprocedureisidentical.

Figure17 TheUSBdriverInstalledsuccessfully.

TheDeviceManagershouldnowlisttherightnamefortheArduino(Figure18).

Figure18 TheDeviceManagershowingtheArduino.

Thisisaoneoffprocessfromnowon,wheneveryoupluginyourArduinoboard,itsUSBdriverswillautomaticallybeloaded,andtheArduinowillbereadyforaction.

Installation on Mac OS X

TheprocessforinstallingtheArduinosoftwareontheMacisaloteasierthanonthePC.

Asbefore,thefirststepistodownloadthefile.InthecaseoftheMac,itisaZipfile.Oncedownloaded,doubleclickontheZipfile,whichwillextractasinglefilecalledArduino.app.ThisisthewholeArduinoapplicationjustdragitintoyourApplicationsfolder.

YoucannowfindandlaunchtheArduinosoftwareinyourApplicationsfolder.Asyouaregoingtouseitfrequently,youmaywishtorightclickitsiconinthedockandsetittoKeepinDock.

Installation on LINUX

TherearemanydifferentLINUXdistributions,andtheinstructionsforeachdistributionarealittledifferent.TheArduinocommunityhasdoneagreatjobofputtingtogethersetsofinstructionsforeachdistribution.Sofollowthelinkbelowandselectoneoftheten(atthetimeofwriting)distributionsonoffer.

Configuring Your Arduino Environment

Whatevertypeofcomputeryouuse,youshouldnowhavetheArduinosoftwareinstalledonit.Younowneedtomakeafewsettings.YouneedtospecifytheserialportthatisconnectedtotheArduinoboard,andweneedtospecifythetypeofArduinoboardthatweareusing.Butfirst,youneedtoconnectyourArduinotoyourcomputerusingtheUSBleadoryouwillnotbeabletoselecttheserialport.

Next,starttheArduinosoftware.InWindows,thismeansopeningtheArduinofolderandclickingontheArduinoicon(selectedinFigure19).YoumayprefertomakeashortcutfortheDesktop.

Figure19 StartingArduinoinWindows.

TheserialportissetfromtheToolsmenu,asshowninFigure110fortheMacandinFigure111forWindows7thelistofportsforLINUXissimilartotheMac.

Figure110 SettingtheserialportontheMac.

Figure111 SettingtheserialportonWindows.

IfyouusemanyUSBorBluetoothdeviceswithyourMac,youarelikelytohavequiteafewoptionsinthislist.Selecttheiteminthelistthatbeginswithdev/tty.usbserial.

OnWindows,theserialportcanjustbesettoCOM3orCOM4,whichevershowsup.

FromtheToolsmenu,wecannowselecttheboardthatwearegoingtouse,asshowninFigure112.

Figure112 Settingtheboard.

Downloading the Project SoftwareThesketches(asprogramsarecalledintheArduinoworld)usedinthebookareavailableasasingleZipfiledownload.Thewholedownloadislessthanamegabyte,soitmakessensetodownloadthesoftwareforalloftheprojects,evenifyouonlyintendtouseafew.Todownloadthem,browsetowww.arduinoevilgenius.com(http://www.arduinoevilgenius.com)and

followthedownloadlinksforthesecondeditionofthisbook.

Whateveryourplatform,theArduinosoftwareexpectstofindallyoursketchesinyourDocumentsfolder,containedwithinafoldercalledArduino,whichtheArduinosoftwarewillcreatethefirsttimeitisrun.SoplacethecontentsoftheZipfileintothatfolder.

Notethateachsketchcomesinitsownfolders,andthesketchesarenumberedbyproject.

Project 1Flashing LEDHavingassumedthatwehavesuccessfullyinstalledthesoftware,wecannowstartonourfirstexcitingproject.Actually,itsnotthatexciting,butweneedtostartsomewhere,andthiswillensurethatwehaveeverythingsetupcorrectlytouseourArduinoboard.

WearegoingtomodifytheexampleBlinksketchthatcomeswithArduino.WewillincreasethefrequencyoftheblinkingandtheninstallthemodifiedsketchonourArduinoboard.Ratherthanblinkslowly,ourboardwillflashitsLEDquickly.WewillthentaketheprojectastagefurtherbyusingabiggerexternalLEDandresistorratherthanthetinybuiltinLED.

COMPONENTSANDEQUIPMENT

Software

First,weneedtoloadtheBlinksketchintotheArduinosoftware.TheBlinksketchisincludedasanexamplewhenyouinstalltheArduinoenvironment.SowecanloaditusingtheFilemenu,asshowninFigure113.

Figure113 LoadingtheexampleBlinksketch.

Thesketchwillopeninaseparatewindow(Figure114)youcan,ifyoulike,nowclosetheemptywindowthatopenedwhenArduinostarted.

Figure114 TheBlinksketch.

Themajorityofthetextinthissketchisintheformofcomments.Commentsarenotactuallypartoftheprogrambutexplainwhatisgoingonintheprogramtoanyonereadingthesketch.

Commentscanbesinglelinecommentsthatstartaftera//andcontinuetotheendoftheline,ortheycanbemultilinecommentsthatstartwitha/*andendsomelineslaterwitha*/.

Ifallthecommentsinasketchweretoberemoved,itwouldstillworkinexactlythesameway,butweusecommentsbecausetheyareusefultoanyonereadingthesketchtryingtoworkoutwhatitdoes.

Beforewestart,alittlewordaboutvocabularyisrequired.TheArduinocommunityusesthewordsketchinplaceofprogram,sofromnowonIwillrefertoourArduinoprogramsassketches.OccasionallyImayrefertocode.Codeisprogrammerspeakforasectionofaprogramorevenagenerictermforwhatiswrittenwhencreatingaprogram.Sosomeonemightsay,Iwroteaprogramtodothat,ortheycouldsay,Iwrotesomecodetodothat.

TomodifytherateatwhichtheLEDwillblink,weneedtochangethevalueofthedelaysointhetwoplacesinthesketchwherewehave

changethevalueintheparenthesesto200sothatitappearsas

ThisischangingthedelaybetweenturningtheLEDonandofffrom1000milliseconds(1second)to200milliseconds(1/5thofasecond).InChapter3wewillexplorethissketchfurther,butfornow,wewilljustchangethedelayanddownloadthesketchtotheArduinoboard.

Withtheboardconnectedtoyourcomputer,clicktheUploadbuttonontheArduino.ThisisshowninFigure115.Ifeverythingisokay,therewillbeashortpause,andthenthetworedLEDsontheboardwillstartflashingawayfuriouslyasthesketchisuploadedontotheboard.Thisshouldtakearound5to10seconds.

Figure115 UploadingthesketchtotheArduinoboard.

Ifthisdoesnothappen,checktheserialportandboardtypesettingsasdescribedintheprevioussections.

Whenthecompletedsketchhasbeeninstalled,theboardwillautomaticallyreset,andifeverythinghasworked,youwillseetheLEDfordigitalport13starttoflashmuchmorequicklythanbefore.

Hardware

Atthemoment,thisdoesntreallyseemlikerealelectronicsbecausethehardwareisallcontainedontheArduinoboard.InthissectionwewilladdanexternalLEDtotheboard.

LEDscannotsimplyhavevoltageappliedtothemtheymusthaveacurrentlimitingresistorattached.Bothpartsarereadilyavailablefromanyelectronicssuppliers.ThecomponentordercodesforanumberofsuppliersaredetailedintheAppendix.

TheArduinoboardconnectorsaredesignedtoattachshieldpluginboards.However,forexperimentationpurposes,theyalsoallowwiresorcomponentleadstobeinserteddirectlyintothesockets.

Figure116showstheschematicdiagramforattachingtheexternalLED.

Figure116 SchematicdiagramforanLEDconnectedtotheArduinoboard.

Thiskindofschematicdiagramusesspecialsymbolstorepresenttheelectroniccomponents.TheLEDappearsratherlikeanarrow,whichindicatesthatlightemittingdiodes,incommonwithalldiodes,onlyallowthecurrenttoflowinonedirection.ThelittlearrowsnexttotheLEDsymbolindicatethatitemitslight.

Theresistorisjustdepictedasarectangle.Resistorsarealsooftenshownasazigzagline.Therestofthelinesonthediagramrepresentelectricalconnectionsbetweenthecomponents.Theseconnectionsmaybelengthsofwireortracksonacircuitboard.Inthiscase,theywilljustbethewiresofthecomponents.

WecanconnectthecomponentsdirectlytotheArduinosocketsbetweenthedigitalpin12andtheGNDpin,butfirstweneedtoconnectoneleadoftheLEDtooneleadoftheresistor.

ItdoesnotmatterwhichleadoftheresistorisconnectedtotheLEDhowever,theLEDmustbeconnectedthecorrectway.TheLEDwillhaveoneleadslightlylongerthantheother,anditisthelongerleadthatmustbeconnectedtodigitalpin12andtheshorterleadthatshouldbeconnectedtotheresistor.LEDsandsomeothercomponentshavetheconventionofmakingthepositiveleadlongerthanthenegativeone.

ToconnecttheresistortotheshortleadoftheLED,gentlyspreadtheleadsapart,andtwisttheshortleadaroundoneoftheresistorleads,asshowninFigure117.

Figure117 AnLEDconnectedtoaserialresistor.

ThenpushtheLEDslongleadintothedigitalpin12andthefreeleadoftheresistorintooneofthetwoGNDsockets.ThisisshowninFigure118.Sometimesithelpstobendaslightkinkintotheendoftheleadsothatitfitsmoretightlyintothesocket.

Figure118 AnLEDconnectedtotheArduinoboard.

WecannowmodifyoursketchtousetheexternalLEDthatwehavejustconnected.Allweneedtodoischangethesketchsothatitusesdigitalpin12insteadof13fortheLED.Todothis,wechangetheline

toread

NowuploadthesketchbyclickingtheUploadtoIOBoardbuttoninthesamewayasyoudidwhenmodifyingtheflashrate.

BreadboardTwistingtogetherafewwiresisnotpracticalforanythingmuchmorethanasingleLED.Abreadboardallowsustobuildcomplicatedcircuitswithouttheneedforsoldering.Infact,itisagoodideatobuildallcircuitsonabreadboardfirsttogetthedesignrightandthencommitthedesign

tosolderonceeverythingisworking.

Abreadboardcomprisesaplasticblockwithholesinit,withsprungmetalconnectionsbehind.Electroniccomponentsarepushedthroughtheholesatthefront.

Underneaththebreadboardholes,therearestripsofconnectors,soalltheholesinastripareconnectedtogether.Thestripshaveagapbetweenthemsothatintegratedcircuitsindualinlinepackagingcanbeinsertedwithoutleadsonthesamerowbeingshortedtogether.

Wecanbuildthisprojectonabreadboardratherthanwithtwistedwires.Figure119showsaphotographofthis.Figure120makesitalittleeasiertoseehowthecomponentsarepositionedandconnectedtogether.

Figure119 Project1onbreadboard.

Figure120 Project1breadboardlayout.

Youwillnoticethatattheedgesofthebreadboard(topandbottom)therearetwolonghorizontalstrips.Theconnectionsonthebackoftheselongstripsrunatrightanglestothenormalstripsofconnectionsandareused

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toprovidepowertothecomponentsonthebreadboard.Normally,thereisoneforground(0VorGND)andoneforthepositivesupplyvoltage(usually5V).

Inadditiontoabreadboard,youwillneedsomejumperwires(seetheAppendix).Theseareshortleadsofafewinchesinlengthofdifferentcolors.TheyareusedtomakeconnectionsbetweentheArduinoandthebreadboard.Alternatively,youcanusesolidcorewireandsomewirestrippersorplierstocutandremovetheinsulationfromtheendsofthewire.Itisagoodideatohaveatleastthreedifferentcolors:redforallwiresconnectedtothepositivesideofthesupply,blackfornegative,andsomeothercolor(orangeoryellow)forotherconnections.Thismakesitmucheasiertounderstandthelayoutofthecircuit.Youcanalsobuypreparedshortlengthsofsolidcorewireinavarietyofcolors.Notethatitisnotadvisabletousemulticorewirebecauseitwilltendtobunchupwhenyoutrytopushitintothebreadboardholes.

WecanstraightenoutthewiresofourLEDandresistorandplugthemintoabreadboard.Thebreadboardusedisoftenreferredtoasahalfsizebreadboardandhas30rowsofstrips,eachstripbeingfiveholes,thenagap,thenanotherfiveholes.Wewillbeusingthisbreadboardalotinthisbook,soifyoucanfindsomethingassimilaraspossible,itwillmakelifeeasier.TheactualboardusedwassuppliedbyAdaFruit(seetheAppendix),butitisaverycommonsizeandlayout.

SummaryWehavecreatedourfirstproject,albeitaverysimpleone.InChapter2wewillgetabitmorebackgroundontheArduinobeforemovingontosomemoreinterestingprojects.