Silly Electronics for Fun and Absolutely no Proft FlüüfffFirstfEditionf–f03/11/2017 FloerefT.fPillowcase,fDevourerfoffAutomobilesf(foere@robocow.be)
Disclaimer Thisfpresentationfisfintendedfforf educationalfpurposesfonlyfandfdoesf notfreplacefindependentfprofessionalf judgement.f Thefpresenter,fnorfthefconvention,f assumefanyfresponsibilityfforfthef content,faccuracyforfcompletenessfoff thefinformationfpresented.f 2
Audience ● Basicfelectronics,ftargetedfatfcostuming. ● Thefideafisftofgetfsomethingfgoingfquicklyfandf easily. ● Wefwillfnotfcoverf(m)anyfadvancedftopicsftoday. – ButffeelffreeftofcomeffndfmefandfIfwillfhappilyf discussfyourfcoolfcostumingfideas. ● Ifwillfassumefyoufhavefsomeffamiliarityfwithf Arduinofandfsimilarfplatforms.f – Iffnot,fdofnotfworry.fThisftalkfshouldfstillfmakef sense. 3
WhyfthisfT alk? ● Thefinternetfisffullfoffinformationfonfhowftof buildffunfdevices,fandfaddfcoolfefectsftof costumes. – Muchfoffitfisfquestionableforfdangerous. – Muchfoffitfrequiresfelectronicsfknowledge. ● Basicfcostumingfgadgetryfshouldfnotf requirefyearsfoffstudy,fnorfbefafdeathftrap. ● Iflikefmyffuzziesfcute,fcuddlyfandf alive ! 4
Content ● SightsfandfSounds Howftofaddffunfgadgetsftofyourfcostume ● Reliability Howftofkeepftheffunfgoing ● Safety Howftofstayfaliveftoftellfthefstory 5
SightsfandfSounds ● Control Arduinofandftheflikes ● Sights LEDsfandfelectro-luminescentffoils ● Sounds Beepsfandfaudio ● Motion Fans,fmotors,fandfservos ● Interaction Buttonsfandfsensors ● Power Sourcesfandfconversion 6
SightsfandfSounds ● Control Arduinofandftheflikes ● Sights LEDsfandfelectro-luminescentffoils ● Sounds Beepsfandfaudio ● Motion Fans,fmotors,fandfservos ● Interaction Buttonsfandfsensors ● Power Sourcesfandfconversion 7
Control:fArduinofandfthefLikes ● Forfdynamicfefectsfyouf needfafprogrammablef controller. ● Therefarefmanyfeasy-to-usef optionsftoday. – Arduinof/fT eensy – RaspberryfPi ● Justfgofout,fbuyfafgoodf starterfkit,fandfgo! ● Caveatfemptor:f5Vfvsf3.3Vf logicflevels!f(Stickfwithf5Vf whenfstarting-out.) https://www.arduino.cc/ 8
LevelfShiftingfDigitalfSignals ● Itfhappensfthatftheflogicflevelsfoffyourf microcontrollerfdofnotfmatchfthefdevicef youfarefconnectingfto.f ● 3.3Vfwasfchosenftofworkfwithf5Vfinputs. – 3.3Vf→f5VffffOK – 5Vffff→f3.3VfNOK Unlessfthef3.3Vfinputfisf5Vftolerant. ● Dofnotfusefresistivefdividersftofshiftfthef levels.fThesefmess-upfsignalftiming.f (ButfOKfforfslowfthingsflikefpushf buttons.) ● Easiestftofusefarefbi-directionalfshiftersf basedfonfMOSFET sf(e.g.fBSS138).f – Thesefarefgoodfforf<f2fMHzfsignals. – Ifftoofslow,fusefafdedicatedflevelf shifterfIC,fe.g.:f74LVx245fseries. ● Thesefneedfafspecifcfsignalf directionfsetfandfrespected! 9
SightsfandfSounds ● Control Arduinofandftheflikes ● Sights LEDsfandfelectro-luminescentffoils ● Sounds Beepsfandfaudio ● Motion Fans,fmotors,fandfservos ● Interaction Buttonsfandfsensors ● Power Sourcesfandfconversion 10
Sights! 11
DrivingfafFewfSmallfLEDs ● LEDsfneedfafconstantfcurrentfsource. – Currentfrelatesftofbrightness. – T oofmuchfcurrentf=fboom! – Voltageftofcurrent?fJustfafresistor. ● T ofcalculatefthefresistorfyoufneed: – Appliedfvoltagef(U) – LEDfforwardfvoltagefdropf(Uf) – LEDfcurrentf(I) ● Equation:fRf=f(Uf-fUf)f/fI – Thefcurvefisfforfaf20fmAfredfLED. – (5fVf–f1.8fV)f/f20e-3fAf=f160f Ω – NearestflargerfE12fvalue:f180f Ω f – Keepfthefunitsfconsistent! ● Iffyoufcan’tffndfthefdatasheetfforfyourf LEDs,fthefvoltagefdropfisf~thefsamefforf allfsmallfLEDs.fItfdependsfonfthefcolour. – Normalfdrivefcurrentfisf~20fmA – High-efciencyftypesfwillfrequirefless! 12 http://www.electronics-tutorials.ws/diode/diode_8.html
WasfthefExamplefSmart? ● No!f – Wefdropf~3.2fVfoverfthefresistorf=f64%fpowerfloss. ● Better:fiffwefusef2fLEDsfinfseries,fUffisfdoubledf(3.6fV)f – Rf=ff68f Ω f – Wefdropf~1.4fVfoverfthefresistorf=f28f%fpowerfloss. ● WithftwofLEDs,ftheftotalfloadfisfstillfthefsame! ● Lessfpowerfisfwastedfasfheat.f – ThreefoffthesefLEDsfwillfjustfaboutfworkfwithf5fV.f (Withoutfafresistor,faflittlefdimmer.) 13
DoesfthisfMethodfScale? ● No!fSeriousflimitationsfwhenfdrivenfdirectlyffromfafmicrocontroller: – GPIOflimits ● GPIOfpinftypicalfmaximumfcurrent:f10f–f30fmAf(sourcefnotfalwaysf=fsink). ● GPIOfbankftotalfcurrentfmayfimposeffurtherflimits. ● CanfonlyfdriveftwoforfthreefLEDsfperf5fVfGPIOfpin. – WithfblueforfwhitefLEDs,fthisfwillfgofdownftofone.f(Uffisfmuchfgreater.) – Af3.3fVfGPIOfwillfnotfbefableftofdrivefblueforfwhitefLEDsfdirectly. – MCUflimits ● T otalfcurrentfgoesfupfquickly.f ● T ypicalfmaximumfvaluesfaref100f–f200fmA. – BrighterfLEDsfrequirefmuchfmorefcurrentfthanf20fmA. ● ForfmorefLEDs,fusefMOSFETfdrivers. – Canfbefscaledftofanyftotalfdrivefcurrent. – Thesefalsofallowfafhigherfsupplyfvoltage,fseparateffromfthefMCU. – Youfcanfalsofbuyfvariousf(multi-channel)fLEDfdriversffromfvariousfvendors. – BUT,ftherefisfafsimplerfway... 14
DrivingfManyfLEDsfthefSimplefWayf DigitalfLEDfStripsf ● Fullfsoftwarefcontrolfoverfeachf“pixel”f (RGBfLED)fcolourfandfbrightness. ● DigitalfinterfacefandfdedicatedfPWMf driverfICfforfeachfLEDfindividually. ● Nofneedftofbuildfafcontrolfcircuitforfwiref allfthefLEDsfyourself. ● T ofmakefitfwork: – Connectfaf5fVfsupply.f(Checkfthis!) ● Carefulfthatfitfhasfenoughfpower! – Connectfyourffavouritefmicrocontrollerf tofthefdigitalflines. – Downloadfafsuitablefsupportflibrary. (Buyfafstripfthatfhasfone!) – Modifyfandfprogramfanfexample. ● Arrangedfinfafmatrix,fthesefcanfalsof displayfsimplefanimations.f(E.g.:f winkingfsmileyfface.) https://www.adafruit.com/ 15
WhatfisfPWM? ● Pulse-WidthfModulation. ● Thefratiofbetweenfonfandfoffisf changedf(modulated). – Expressedfinf%fdutyfcycle. ● Thefaveragefoffthesefpulsesfinftimef resultsfinfanfin-betweenfvalue. ● IffthefPWMfratefisffastfenoughf(orf fltered),fthefeyefdoesfnotfperceivef thefblinking. ● Theftechniquefisfusedfaflot: – ClassfDfaudiofamplifers. – Motorfvariablefspeedfdrives. – LEDfdrivers. – Servofpositionfencoding. 16
Demo 17
Electro-LuminescentfLights ● Unique,fcool,falmostfbiologicalfglowfefect. ● Manyfdisadvantages: – Highfdrivingfvoltagef(butflowfcurrent)fneedsf specialfinverterf(90f–f150fVftypical) – Needfanfinverterfwithfcontrolfinputfiffyouf wantftofchangefbrightnessfinfsomefway. – Onlyfonefspecifcfcolour. – Ratherfdim.fWillfonlyfworkfwellfinfthefdark.f (Eg:fduringfdances) ● Wouldfsuggestflookingfinto: – ELfsheetf→fLEDfstripsfunderftheffur,forfunderf afdifuserfsheet.f – ELfwiref→fSide-Emittingfplasticfopticalffbre ● Drivefitffromfafpowerfulf(fewfWatt)fRGBfLED ● Variousfthicknessfofffbrefexist. ● Cheap!f(SeefAlibaba,faboutf€1fperfmeter.) – Lightfsourcef(calledfaf“lightfengine”)fisf extra.f3fWfversionsfarefinexpensive. 18
SomefOpticalfTricks ● ForfmorefevenfLEDflighting ● Forftinyfpointsfofflight – 1fmmfplasticfopticalffbref – RunfmultiplefLEDfstripsfinf (POF)fisfinexpensive.f parallel,fwithfafhalffLEDf – Joinfseveralfstrandsftofaf spacingfofset,fforflargerf brightfLED,forfusefafrealflightf areas. enginefdriverfmodule. – Usefanfopticalfdifuser – Feedfthefotherfendsftofwheref ● Privacyfwindowfflm. youfwantflights. ● Thin,ftranslucentffoam. – Jacketedfandfnon-jacketedf ● Frostedfplexiglass. POFfexists. ● Realfdifuserfflm. – Idea:fglowingfwhiskers! 19
SomefOpticalfTricks ● Illuminatingflargerfareas ● Complex,fstaticfshapesfusingfdecal – Printfonfoverheadfprojectorf – Useflensesfiffyoufcanfsparef transparencyfflm.fOrfcutfoutfaf thefdepth. shapeffromfsomefopaquef – Usefafdifuserftofgetfanf material. evenly-litfarea. – Afdifuseflightfsourcefwillfmakefaf – Stencilsfcanfbefincorporatedf bigfdiference. intofthefopticalfpath. – Projectingfontofafdifuserfwillfalsof – Usefafrayftracer.fThisfletsfyouf work. testflensesfbeforefbuying. – Idea:fglowingftattoofunderffur! https://arachnoid.com/OpticalRayTracer/ 20
SightsfandfSounds ● Control Arduinofandftheflikes ● Sights LEDsfandfelectro-luminescentffoils ● Sounds Beepsfandfaudio ● Motion Fans,fmotors,fandfservos ● Interaction Buttonsfandfsensors ● Power Sourcesfandfconversion 21
BeepsfandfBoops ● Simplefsquare-waveftones. 330R ~ok – Vintagef8-bitfsound. – Yourfmicrocontrollerfcanfdofthis! – But:flimitedfrangefoffexpression. – Plentyfoffexamplesfon-line,fmodifyf asfneeded. ● Dofnotfjustfattachfafpiezofelementf asfshownfinfmostfon-linefexamples.f – Needsfaffewfextrafpartsftofprotectf yourfMCUfI/Ofpinfandfthefpiezo. – Notfloudfenoughfforfperformance. ● Usefanfexternalfamplifer! – Afveryfbasicfinterfacefcircuitftof lineflevelfisfsuggestedfhere. 22
Demo Image creator unknown 23
Audio ● Whatfkindfoffaudio? – Musicforfsoundfefects?f – Characterfvoicefwithfsqueaksforfwords? ● Overcomefmufedfcostumefvoices! ● Soundfsource – Phoneforfsimplefportablefmusicfplayer. – Therefmanyfaudiofadd-onfboards. – AnfadvancedfMCUfcanfdofanything. – Considerfhowftofcontrolfthefaudio! ● Amplifer – Buyfanfampliferfkitforftake-apartfsomef battery-poweredfloudspeakers. – Class-Dfinfbridgeftopologyfpreferred! https://www.adafruit.com/ – Makefsurefit’sfbothfthermallyfandf short-circuitfprotected. ● Loudspeaker – Criticalftofsystemfperformance! 24
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