RobotMaskChallenge
Description
Inthis activity,students are exposedto feedback loops and latency(thedelay betweencommandand response)by wearing a blindfold mask containing LED lights and using itastheir only sourceofinformationwhile navigating throughacomplexset of obstacles.Studentsdevelop acommunication protocolto allowone student(the“controller”) to direct the other (the“robot”) throughtheobstaclesquicklyandefficiently,using a code systemtocommunicateinstructions with only LEDlights.
Thisactivity helps studentsby:
•Focussingattentionon thewide variety ofinputs and feedback mechanismsprovidedbyhumansenses
•Illustratingthe challenge ofoperatingin an environmentwherefeedbackis limited andsubjectto latency
•Requiringteamworkandcooperation to accomplisha task
•Givingthem practice usingthe terms and tools needed toconstructa simple electroniccircuit
LessonOutcomes
Students willbeable to:
•Describethe types of feedbackloopsprovided byhuman senses
•Describethe steps in acommunication protocol and relate them to human conversations
•Explainthechallengesof latencyincontrol loops
•Create a simple electroniccircuit
•Useappropriate terminology to describethe components in their electroniccircuit
Assumptions
Students willhavebasic understandingofthe following:
•Useofsimple hand tools:
–Wirestrippers
–Hot glue
–Solderingiron
•Onlinevideogames
•Strippingandsolderingwires
•Relieving strain on wires
•Constructing amask
•Creatingacircuit using anLED,resistor, battery andswitch
KeyTerminology
Anode:the“positive”sideofanelectricalcomponent.
Cathode:the“negative”sideofanelectricalcomponent,oftenmarkedwithadistinguishingfeature suchasaflatsideon LEDs, orastripeonelectrolyticcapacitors.
Communicationprotocol:asetofrulesfortransmittinginformation.
Feedbackloop:aniterativeprocessinwhichanoutputsignaliscontinuallymodifiedinresponsetotheeffectoftheoutputsignal.An examplewouldbeacar’scruisecontrol system,wherethethrottleposition (the output) ismodifiedbasedonthevehiclespeed (the effectoftheoutput).
Latency:thedelaybetweenthetransmissionandreceptionofasignal.
LED:LightEmittingDiode.AdevicethatconvertselectricityintolightwhenelectronscrossasemiconductorP-Njunction.The wavelength,orcolour, ofthelightisdeterminedby theenergydropacrosstheP-Njunction.
LoadingZone:thestartingplacewherethepayloadwillbefound.CyborgswillmovethepayloadfromtheLoadingZonetotheObjectiveZone.
ObjectiveZone:theendingplacewherethepayloadshouldsuccessfullyenduptoscorepoints.
Payload:theobjectorobjectsthatwillbe movedduringthechallengefromtheloadingzone(starting place)totheobjectivezone (endingplace).
Sensor:adevicethatprovidesinformationabouttheenvironmenttoadeviceorrobot.
Solder:alowmeltingpointalloy forconnectingmetalliccomponents.Typically usedinelectronics,plumbingand jewellery.
Strainrelief:adesignfeature,componentormechanism intendedtotransferstressintoaflexibleconnectioninsuchawayastoreducefatigueandstressconcentrationintheconnection.
EstimatedTime
Totaltime 5–8 hours:
1–2hoursof lessontime
3–4hoursof build andtesting time1–2hours of activity time
RecommendedNumberofStudents
Two students per mask to amaximum of 20 students,basedonBCTechnology Educators' BestPracticeGuide.
Facilities
•Any classroom or largearea such as acafeteria or gymnasium
•A multipurpose techstudiesshopor lab withaccess tosoldering irons
•Spaceto navigate with variable hazardsfor navigation
•Fixed obstacles: workbenches,desks, other permanent or heavylarge objects
•Random obstacle:garbage can, chair or othermovablesolidobject
Tools
•Solderingiron
•Drillpress(orsuitablehanddrill arrangement)
•Whitneypunch (if available)
•Wirestrippers
•Screwdrivers
•Scissors
•Hot glueguns
Materials
•LEDs
•Multi-conductor stranded wire
•Batteriesandbatterypacks
•Switches
•Mask-makingmaterial (poster-sizedcardstock, tape)
•Mask-decoratingtools (felt pens, glue stick, hot glue,paint)
Resources
•The“Super Cyborg” RobotMask Challenge (onpage8)
•Robot MaskChallenge Score Sheet(onpage 7)
•Instructions for Building theControlBoard (onpage10)
•Mask Examples(onpage 15)
•Sensors and Control Loops Discussion Suggestions (onpage 17)
•Communication andControl LoopsDiscussion Suggestions(onpage 19)
AdditionalSupportMaterials
“Super Cyborg” RobotMask Challengehandout
Procedure
Day1: / Lesson: / IntroduceactivityExplainthechallengeDemonstrate mask-building procedure
Activities: / Put students into teamsBegin mask construction
Day2: / Lesson: / Sensors and control loops(see“Resources”for discussion guide)Communicationprotocols(see“Resources” fordiscussion guide)
Activities: / Complete mask construction and decorationDevelop communicationprotocol
Day3: / Lesson: / Buildingcontrolboard
•LEDs –anode andcathode
•Resistors
•Switches
•Batteries – positiveand negative
•Strainrelief: emphasize its importanceto ensure reliablecommunication
Activities: / BuildcontrolboardInstall LEDs in maskConnect board andLEDsusingproperstrain relief
Day4: / Lesson: / Review the challenge
Activities: / AssiststudentstocompleteunfinishedmasksPracticeruns for students withcompleted masks
Day5: / Lesson:
Activity: / Review sensors, control loops, communicationprotocolsReview challenge rules
Robot maskcompetition
Follow-up:Quiz onsensors, feedbackloops, communicationprotocolsandmask wiring.Teachers shouldcustomizetheirquizbasedon classroomdiscussionand topics covered.
Assessment
The evaluation of this lessonisbasedon thelearning outcomes outlined above.
Prior toteachersusingthe evaluation griditis recommended that studentsperform someformofpeer-assessment andself-assessment.
OutcomeToBeAssessed / 6 / 5 / 4 / 3 / 2 / 1 / 0Outcome1 / Describethetypesoffeedbackloopsprovidedbyhumansenses
1.1 / Candescribe human feedback loops.
Outcome2 / Describethestepsinacommunicationprotocolandrelatethemtohumanconversations
2.1 / Understandsandcandescribecommunicationprotocol.
2.2 / Relates protocols tohumaninteraction.
Outcome3 / Explainthechallengesoflatencyincontrolloops
3.1 / Understandstheconcept of latency.
3.2 / Candescribetheissues latency presents incontrolloops.
Outcome4 / Createasimpleelectroniccircuit
4.1 / Canidentifycircuitcomponents.
4.2 / Canassembleafunctionalcircuit to achieveagoal.
Outcome5 / Usesappropriateterminologytodescribethecomponentsintheirelectroniccircuit
TotalPoints:
6 / Completedsuccessfully atthe exceptional level / Exemplary5 / Completedsuccessfully athigher than theexpected level / Accomplished
4 / Completedsuccessfully to theexpectedlevel / Emerging
3 / Attemptedsuccessfullyat the minimumlevel / Developing
2 / Attempted- Unsuccessful- ClosetoSuccessful / Beginning
1 / Attempted-Unsuccessful / Basic
0 / NotAttempted / N/A
Comments:
ExtensionActivities
Challengethe studentsto navigate theschool usingtheirmasks.
Challengethe studentstoidentify robotsthat use sensors to develop paths and navigate:
•Areself-drivingcars “robots”?
•Do“Roombas”learn tonavigate?
RobotMaskChallengeScoreSheet
PenalitiesFirstPartner / SecondPartner / BaseScore
#ofLEDS2 / DecorationStyle / Try
# / Noise(10) / Mask(20) / MinorObstacle(1) / MajorObstacle(1) / RandomObstacle(1) / AccuracyScore / TimeinSeconds / TotalScore
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
The“SuperCyborg”RobotMaskChallenge
Onepartner is the robot, andthe other is the controller.Do yourjob.Doitwell.Doitfast. Victoryis yours!
TheChallenge
Workingtogether,you andapartnerwill:
1.Create a “robot mask” that will turn onepartner into a human-machine cyborg.
2.Create a “controlboard”that will allowone partner to controlthe actions ofthecyborg.
3.Create acommunication protocoltosend informationfrom the controller tothe robot.
4.Practise your communicationand control systems to completeatask.
TheRules
1.Themaskmust completelyobscureall visualinput from the surroundings.
2.Theonly communication that the cyborg may receive shallbefrom the LEDs.
3.TheLEDs mustbe controlled by switches onacontrol board.
4.Thecontrolboard must be operated by the controller.
5.Thecontrol boardmustbe connected tothe mask by a cable.
6.Thecable must remain slack atalltimeswhencontrolling the cyborg.
7.The“payload”willbe providedbyyourteacher.Atthebeginning of yourtask the payload willbe locatedinthe“loadingzone”asdefinedbyyourteacher.
8.Thestartpositionwill be indicatedbyyourteacherwith a mark on thefloor.
9.At thebeginningofthetask the cyborgmust haveafoot incontact withthestartlocation.
10.The“objectivezone”will be definedbyyourteacher.
11.Thegoal isto move the payload asquicklyas possible from theloading zone tothe objectivezone.
12.Placingthe payload close tothe objectivewill improve yourscore.
13.You maynot throw the payload.Youmustcarry it from the loadingzone tothe objectivezone.
14.The“randomobstacle” ismoved bytheteacherbetween eachrun.Therandomobstacleis movedafter the cyborgiswearing themaskandisin thestartlocation. Contacting therandom obstacle resultsina 10-point penalty.
Self-assessmentScoring
Thefollowingare therules for self-assessmentscoring. They canbe usedalongsidethe teacherevaluation grid.
Thegoal is to keepyourscore aslowaspossible.Thescore is calculated asfollows:
TotalScore=BaseScore+ TimeScore+ AccuracyScore+Penalty Score–DecorationScore
The basescoreis the number ofLEDs,squared: 1 LED is a basescore of 1; 6LEDs is abasescoreof 36. Design your communication protocol wisely to usethe minimum bandwidth,butbeware: limited bandwidth mightincrease yourlatency!
Timescoreisthetime inseconds from when the cyborg’sfoot leaves the start position until thecyborgreleasesthe payload and raisesboth hands above theirshoulderstoindicate theyarefinished.
Accuracy scoreisthesquare of the distance(in centimetres) ofthenearestedgeof the payload to theobjective zone. If the payload covers any or allof theobjective zone, theaccuracyscoreiszero.
Penaltyscoresare assessedby the teacher accordingto thechartbelow.Penalties may beassessedeven for “accidental” or“minor” offenses. Itistheteam’s jobto ensure thattheyavoidpenalties.Teamsthatintentionallytakepenaltiesmay be disqualified.If a penaltygives a teamanunfairadvantagetheymay be disqualified or requiredtore-starttheirrun.
Offense / PenaltyPointsMaking noise,even briefly and unintentionally, or any other attempt tocommunicatewiththecyborgusingsomething otherthanthe LEDs. / 10
Havingthe mask“slip” ormovefor any reasonsuchthat it allowseventhepossibility of seeingoutsidethe mask. / 20
Contacting a “fixed obstacle” such as a chair, desk or other obstacle.Minoroffensesare unintentionalcontact wherethecyborgbacksoffimmediately.Amajor offenseiswherethecyborgfollows theobstacle,obtainingpositionororientationinformation. / Minor offense: 1
Major offense: 10
Contactingtherandomobstacle. Thispenaltyis appliedonly once. / Firstoffense:10
Subsequentoffenses:0
Decorationscoreis: / 0 / For an undecoratedmask
5 / Fora basic maskwith simple artwork ordecoration
10 / Fora mask with creativeor detailedartwork ordecoration
SeeRobotMaskChallengeScore Sheet onpage 7
InstructionsforBuildingtheControlBoard
Thecontrol boardis asimpleelectronic circuitconsistingof anumberof LEDs,eachwith acurrent-limitingresistorandcontrolled bya pushbutton switch.The powersourceis typicallya9Vbattery.Figure 1shows theschematic for acontrolboardwithfour LEDs. Students maychooseto useasfewor asmany LEDsasthey feel willbe optimal for completing the challenge.
Notethat the battery and switches will belocated onthecontrolboard,whilethe LEDs and resistors will belocated inthemask.This requires acable toconnect thecontrol boardtothe mask. A typicalcable length is roughly 2m long—enoughto allow a reasonable amountofslackinthe cableduringthe competition.
BAT19V
Each teamwillrequire acable withone conductor perLEDplus oneconductorto supplypower tothe LEDs.For a set-upwithfourLEDs, a five-conductor cable will be required.Itisfinetouse a cable withextraconductorsandleave someunused.
Therearea number ofsuitable cabletypes(Figure2). Thepreferredcabletypeisthe multi-colouredribboncable(sometimescalledrainbowcable) attherightof the photo,asitislightweight,flexibleand can be easilyseparatedtoprovidethecorrect number ofconductors foreach team.
Thewirecolours areuseful for tracing connections betweenthecontrol boardand themask.
LED1
LED2
LED3
LED4
R1470R
R2470R
R3470R
R4470R
SW1
SW2
SW3
SW4
Figure1—Controlboardschematic
Figure 2—Variouskindsof multi-conductorstrandedwire
Ideallythe cable will be madeofstrandedwire,as solid-core wireis less flexibleandhas atendency tofatigue(break)at inopportunetimes. Studentsmay noticethat solid-corewireiscommonly used in stationaryor architectural applications, whilestranded wireisused inmobileapplicationssubjecttoflexing or vibration,suchasvehiclesandmachinery.
Thereare anumberofways to createthe control board, depending onthe toolsandresourcesavailable.Twodifferent constructions areshown (Figures3and4), one usingABS plastic,purchasedswitches (momentary, normally open (“N.O.”) pushbuttonswitches), and theother a“perfboard” prototypingboard toholdtheLEDs and resistors in place.
Theother controlboard uses offcuts of wood andplywood alongwith screws and manufacturedswitches(Figure5).Theswitchesmay be manufacturedofanyreasonablyflexiblesheetmetal.Inthis casethey use themetal strappingthatis used tosecurestacksof lumber.This strappingcanusuallybe obtained for free fromalocal lumber supplystore.(Note that the paint onthestrappingmustbe sanded off in order to ensure anelectricalconnectionwith thescrews.)
Figure 3—Twostylesofcontrolboard -front
Figure 4—Twostylesof controlboard -back
Figure5—Control board with custom-builtswitches
Notethe strain relief provided byweaving thecable through holes drilled or punched inthecontrolboard. Whilethereare manywaystoprovide strain relief, itis essential for reliable robotoperation. Cables thatlack strain relief will pullon theelectrical connections, causing them tofail.
Thebatterymountis madebybendingan offcut of sheetmetaltoclip thebattery inplace. Thisprevents strain inthe wiringbetween thebattery andcontrol board andallowsbatteries to besharedbetween teamsor easily returned at the endofclass. The batteries are oneofthemoreexpensive components in this project.
Electricalconnections tothe switches are madebysolderingwiresin place. Connections onthewoodenboard aremade by wrapping thewire aroundthe screw, then tightening thenut.Thismakes iteasier to adjust the wiringshould the studentsmake amistake.
For mounting theLEDsinsidethe mask itmakes sense tobuild aboard tohold theLEDsandresistors. Thisensures thatthecable canbe strain relieved at the robot end and allows theLEDs tobetested before beinginstalled inthemask.Againthere area number of optionsforconstructingthe LED mountingboard,includingperfboard (Figures 6and 7) anda custom-builtequivalent madeof offcuts(Figures 8and 9).
Figure6—Perfboard-frontFigure7—Perfboard-back
Figure8—Wood LEDmount-frontFigure9—Wood LEDmount- back
Buildingandtesting theLEDsandcontrol boardbefore installingtheminthe mask also allowsa teamof twostudentstowork in parallel: one canbe working onthe controlswhilethe otherworks onbuildingor decorating the mask.
Oncethe controlboard andmaskarecompleted they canbe joinedtogetherbyinserting theLEDs into themask(Figures10 and 11) and holdingtheminplace with tapeor hot glue.Notethat additional strainreliefbetween thecable andthe maskmay need to be provided,usually bytaping the cable securelyto the mask.
Figure10—Wood boardin cardboardmaskFigure11—Perfboardincardstockmask
The studentsmaynowdon their masksandpractisetheircommunicationprotocol.
Troubleshooting
If thereareproblems, try the following:
1.Check the LED polarity.The anode, or positive side, istherounded sideof astandard 5mmLED andshouldbe connectedtothe positivesideofthe battery. The cathode, ornegativesideoftheLED,shouldhave a flattenedsideandshould connect (via a resistorandswitch)tothe negative sideof the battery.
2.Check thebattery withavoltmeter. A9Vbattery should bedelivering at least 8V.
3.Useavoltmeter to check the voltageacross the LED and resistor when theswitch ispressed“on.” Ifyou see avoltage dropacross the LED andresistorbut the LED doesnot turn on,
it is possible that the LED hasbeenburned out. Thishappens when an LED isconnectedtoa powersupplywithout acurrent-limiting resistor. ReplacetheLED.If you do NOT see avoltage drop, then investigate for aproblemwiththe wiringorswitch.
UsingDifferentBatteries
Thereis no requirementtousea9Vbattery.Any batteryorbattery pack between3V to12Vshould work fine.
UsingDifferentResistors
Just aboutanyresistorbetween 300ohmsand 2000 ohmsshouldwork okay.Ideallyyourresistor ischosento work with yourbattery voltageand LED “forward voltagedrop”to deliver5–20mA ofcurrent througheach LED.For mostLEDs the forwardvoltagedrop is roughly 2V.For blue or white LEDs the voltagedrop is closer to3V.Todetermine theresistorvalue, use thefollowingformula andselectsomethingthatyou have instockthat is closeto this value:
(Battery Voltage –ForwardVoltage Drop)×100=ResistorValue
It is necessary touse oneresistorper LED to ensure equal current to eachLED. Ifthecircuitshares one resistor across allthe LEDs, then allthe LEDs will dim whenevermorethan one LEDis turnedon.
MaskExamples
Themostbasicmaskconsistsof a cylinderofcardstock, taped to fit securelyoverthecyborg’sheadwith theLEDs mountedonthe insidesothey are visibleto therobot. Graphicscanbeaddedtothe exterior forpersonalization, depending onthe time availableandthe creativity
of the students. Figures12,13and 14 givesome ideaofthe widerange of design optionsavailable.Note,however, thatit doestake additional timeand resourcestodesign andcreateuniquemasks.
Figure12—TheBCITTTEDClass of2012shows off theirrobotmasks
Figure13—TheBCITTTEDClass of2013shows off theirrobotmasks
Figure14—Arobotmaskcreatedfromacardboardbox
SensorsandControlLoopsDiscussionSuggestions
HumanSenses
Askstudents to describewhathuman senses theyuseto controltheirbody:
Howdotheyknowwheretheyare?
•Sight: References known objects or locations. Provides distance informationto objects.
•Touch: In adark roomthey can followawall.Theystopwhen theyhit an object.
Howdotheyplanapath?
•Sight:Identify goalandobstacles;planshortest, safest route.
•Memory: What pathworkedbest last time?
•Learning: What pathworked best for the other peoplewho triedto navigate this path?
Howdotheyplaceanobjectprecisely?
•Sight: Theycanseewhere they areputting it inreferenceto other objects.
•Touch:Theycan feelotherobjects and placethe object in relationto thoseobjects.
•Proprioception: Theycanfeel thepositionof theirbody, limbs and digits.
Howdotheyreceivefeedbackontheirprogress?
•Sight: Theycanseehow they areprogressing.
•Hearing: Theycanhear peopleyelling “Stop” or“GoLeft”—lowlatency communication!
RobotSensors
What sensors do robots haveto controltheir “body”?
Howdotheyknowwheretheyare?
Sight: Visualsensing is a bigchallengeforrobots.
Simple “sight” sensors include:
•Rangefinders: can identify thedistancetoan object.
•Infrared
•Ultrasonic
•Laser: Colour sensors canidentify colours at shortrange.Object sensors canidentify thepresenceor absenceofan object.
Complex “sight” sensors include:
•Videocameras:image processingis a real challenge: How does arobotknow what a“table” lookslike?
•LIDAR: scanning laser beamsdevelopa3D “point cloud” view ofsurroundings.
•Structured light imaging: XboxKinectsensors.
Touch: Robotsare goodatsimple touchsensing but poor at complexsensing.
•Mechanical switches: “Limit switches”are verycommon and reliable.
•Pressuresensors: Can detect how hardsomething is beingtouched.
•Texturesensors:Robotshavereal difficulty identifyingrough,wet or fuzzy surfaces.
Triangulation: Sensingtheir location relative to knownobjects
•GPS: measuresthedistancetoorbitingsatellites.
•Other radiotransmitterswithknownlocations canalsobe used.
•Cellphone towers and Wi-Fihotspots canbe used.
Dead reckoning:Measuringdistance travelled from aknown point.
•Stepper motorsusedin CNC machines and 3D printers moveavery precise distance.
•Encoders measure howfar awheel has turned.
•Accelerometers measure how fast arobotis moving.
•Gyros track whether arobot is turning.
Howdotheyplanapath?Thisisabigchallengeforautonomousrobotsandself-drivingvehicles.
Sight: Robots can usevisual sensors toidentify objects. How do they recognize what theobjects or obstacles are?
Memory: Can theyrelate theobjectstheysenseto amap?Learning: Can theycreatetheirown mapofan unknownarea?
Howdotheyplaceanobjectprecisely?
Sight: Opticalsensors can providepreciselocation relative toknownmarkings.Touch: Switchesandobjectsensors can place anobjectprecisely.
Proprioception: Encoders and potentiometerscandetect thepositionof joints andslides.
Howdotheyreceivefeedbackontheirprogress?
Sight:Opticalsensors can measurefinalproductsforqualitycontrol.
Electricalcurrent sensors: Can detect whenmotorsarestalled, jammed or stuck.Human oversight:“Kill” switchesandsafety interlocksprevent serious damage.
CommunicationProtocolDiscussionSuggestions
HumanCommunication
Whatarehumancommunicationprotocols?
Howdo you initiateaconversation?
Howdoessomeoneknow you aretalking toTHEM?
Howdo you know theother person isready to communicate?Howdo youcheck to ensure the other person heard you?
Howdo youcheck to make suretheyunderstood you?
Howdo youavoid“cross-talk” (having more than one persontalkatonce)?Issecurity anissue?
Howdo youmakesure noone else interceptsyourcommunication?Howdo you terminateaconversation?
Dodifferent cultures or language groupshavedifferentprotocols?
RobotCommunication
Robot communication protocols have todo many ofthesame things ashuman protocols.Eachprotocolhasitsown rules forinitiating,terminatingand confirming communications.Thesearesomecommon protocols used in computer and robotic communications:
•TCP/IP (TransmissionControlProtocol/ InternetProtocol)
•RS-232is a serialdatacommunication protocol.
•USB is ahigherspeedserialdata communicationprotocol.
•CANis acommunication protocolused incars and robots.
•I2Cis acommunication protocolused betweenmicrochips.
Latencyandfeedback
Nomessage istransmittedinstantaneously; even computers havedelays.
Inan onlinecomputergame“ping time”is the timeittakesfor a message to get from theplayer’s computer to thehostcomputer and back. Slow pings are nofun.
Have youeverheardadelaywhen calling overseas onaphone or Skype?Fibre optic cableshandle most data andhavealow latency.VancouvertoHongKong is about170 ms;VancouvertoCalgary is onlyabout13ms.Satelliteshave longerdelays because thesignalshave to travelfurther. Minimumlatency for ageostationary satellite signal is 240 ms.Latency is abig dealwhencontrolling space probes. It cantake overhalfanhourfor asignal to goto Mars andback!
Latency is abig deal infeedbackloops. A feedback loop senses an event, then sends acommandto adjust fortheevent. If the temperature goesup, athermostat willturn off theheater. If acargoes downhill, cruisecontrolwill cutbacktheengine power.Ifyour“robot” isabout to walkintoadesk,the “controller” will senda“stop”command.
Low latency is important forfeedback loops.It allows the robot to move fasterandposition things more precisely. How does a highping timeaffect your feedback loopwhen gaming? Whatis thefeedbackfor your“robot” and“controller”?Whatcontrols the latency for your robot?
DesignaCommunicationProtocol
Youwilldesign a communicationprotocolforyourrobotmask.Itwill be specific toyouandyourpartner.
Youwill needto consider the following:
•What datado you needto communicate?
•How manyLEDs will you need tocommunicate thedata?Fewer LEDsmeans less work towire,butit’smore difficult to learn theprotocol!
–Isit possibletocreatea communicationprotocol usingjust one LED?
–Would it be agood ideato createa protocolusing just one LED?
•Howwill you know thatthemessage hasbeen received?
•Howwill you know that the correct message has been received?
Write down yourcommunicationprotocol andpractise it byhaving the “controller”describe theLED patternverbally and the“robot” respond.
Submit your communicationprotocolto your teacher for assessment.