Lemon 7ch Telemetry Rx Manual Feb12 - rc-netbutik.dk · Lemon Rx 7-Channel Integrated Telemetry...
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Transcript of Lemon 7ch Telemetry Rx Manual Feb12 - rc-netbutik.dk · Lemon Rx 7-Channel Integrated Telemetry...
LemonRx7-ChannelIntegratedTelemetryReceiver 1
InstructionsLemonRxDSMX-Compatible7-ChannelFull-Range
IntegratedTelemetryReceiverFullRangewithDiversityAntennaandPPM
TheLemonRx7-ChannelIntegratedTelemetryReceivercombinesinasinglecompactpackagethefunctionsofahighperformanceDSMX-compatibleradiocontrolreceiverandafull-rangetelemetryunitthatsupportsSpektrumtelemetry-enabledtransmitters.
Contents PART1.Overview........................................................................................................................................1
PART2.UsingtheLemonReceiver/TelemetryUnit....................................................................................5
A.BasicRequirementsandSetup............................................................................................................5
B.Binding.................................................................................................................................................6
C.Failsafe.................................................................................................................................................7
D.Telemetry............................................................................................................................................8
E.ConnectingServosorFlightController................................................................................................8
PART3.AdditionalInformationforAdvancedUsers...................................................................................9
A.PPMmode...........................................................................................................................................9
B.RSSI......................................................................................................................................................9
C.AntennasandSatellites.....................................................................................................................10
D.PowerConsiderations.......................................................................................................................11
E:VoltageRecalibration.........................................................................................................................11
F:CalibratingtheOptionalV/ISensor...................................................................................................13
G.CreatingandReadingTelemetryLogFiles........................................................................................15
H.ServoOutputTiming.........................................................................................................................18
PART 1. Overview • BoththeradiocontrolreceiverandthetelemetrytransmissionfunctionsoftheLemonunitare
classifiedasfullrange.Thisisachievedusingdualantennasanddiversityswitchingtoensuremaximumsignalreliabilityinbothdirections.Note,however,thatwhilethereceiverhascontrolsignalrangewellbeyondthenormallimitsofvisibility,thelowerpowerofthereturntelemetrysignalmeansthatthetelemetrydisplaymayoccasionallyfreezewhilethemodelisstillunderfullcontrol.
LemonRx7-ChannelIntegratedTelemetryReceiver 2
• Thelownoiseamplifier(LNA)inthereceiverensuresmaximumsensitivitytodetectweakradiofrequency(RF)signals.UsersshouldexperienceanoticeableimprovementinrangecomparedtothepreviousgenerationofLemonRxreceiversandtootherbrandsofDSM2andDSMXreceiversandcompatibles.Independenttestinghasshownthisreceivertohavesignificantlymorerangeinastandardreducedpowerrangetestthanseveralothercomparablereceiversthatweretestedunderidenticalconditions.
• Theunithasantennasoftheextendedtypeforversatileplacementinmanytypesofapplication.Theactivereceiving/transmittingelementisthelast32mmoftheantennacable,whichhassemi-transparentwhitePVCshield.
• Inaddition,aDSMXsatellitereceivercanbeattachedtoenhancesignalsecurity.SatelliteswithandwithoutdiversityantennasareavailablefromLemonRx.
• Telemetryfromtheunitcanbothbedisplayedon-screenandspokenbycurrentSpektrumtelemetry-enabledtransmitters:DX6G2,DX7G2,DX9(includesBlack),DX10t,DX18,DX18QQ,DX18G2(includesStealth),andDX18t.TheolderDX8,andtheoriginalDX18,candisplaydataon-screen,butlackvoicecapabilityandthereforecannotspeakalarms.1
• Built-insensorsprovidereceivervoltage,internaltemperatureandRSSI(signalstrength).Theincludedexternalsensorsaddflightpackbatteryvoltage(whenconnectedtothepositiveconnectionoftheflightbattery)andamoreaccurateexternaltemperatureprobethatautomaticallyreplacestheinternalvalue.
• Anoptionalvoltage/current(V/I)sensorisavailablethatmeasuresupto30Vand60A(seetheLemonRxwebsiteunderAccessories).
• AtrueRSSI(ReceivedSignalStrengthIndicator)presentsvaluesonascaleof100to0assignaldeclines;thevalueisdisplayedasparameter"A"onthetransmitter’sFlightLogpage.
• RSSIOutforsupportofanon-screendisplay(OSD)isalsoavailablefromthereceiver(usingthesuppliedlead)intheformofananalogvoltagerangingfrom3V(=100%)to0V.
• Theunitrequiresapowersupplyof4.5Vto7.4V.Itisimportanttonotetheminimumvoltage,whichishigherthanrequiredbymostLemonreceivers.Inparticular,thisreceivercannotbeoperatedfromasingleLiPocell.
• ThepinslabeledBind/AUX2dodoubledutyasbindpinsaswellasChannel7(AUX2);whenabindplugispresentthereceivershutsdownservooutput.EithertheservocanbeconnectedafterbindingoritcanbeattachedtoonebranchofaY-cable,withthebindpluginsertedintotheotherbranchandthenremovedafterbinding.
• Noseparatestand-alonetelemetryunitisrequiredwiththisreceiver.Norcansuchaunit,Lemonorother,beconnected,astheseconddatastreamwouldinterferewiththatoftheintegratedunit.
• UserPresetFailsafeonallchannelscanbesetbythepressofasinglebuttononthereceiver.Iffailsafeisnotset,theunitdefaultstoemittingnopulsesonlossofsignal.
1UnliketheLemonstand-alonetelemetryunit,thisreceiverdoesnotworkwiththenowobsoleteSpektrumTR1000STiTelemetryInterfaceforiPadandiPhone.
LemonRx7-ChannelIntegratedTelemetryReceiver 3
• ThereceivercanbesettooutputeitherindividualPWMsignalsforeachchanneloracombinedPPM(cPPM)signal(ineitherFutaba/HitecorJR/Spektrumchannelorder)carryinginformationforallchannelsonasinglewire.
• LEDlightsindicatethereceiverstatusasfollows:
o RED:SOLID–successfulbindRFlinktotransmitter;FLASHINGRAPIDLY–bindmode;
o GREEN:OFF–nopulseonsignalloss;SOLID–presetfailsafe;
o BLUE:OFF–PWMservomode;FLASHING–PPM-Fmode;SOLID–PPM-Jmode;
Figure1.1Whatyougetinthepackage.
Thepackvoltage/currentsensorshownontheleftisnotincludedwiththereceiverasstandard.ItisanadditionalaccessoryandisthesameasusedwiththeLemonstand-alonetelemetryunit.
LemonRx7-ChannelIntegratedTelemetryReceiver 4
Figure1.2TheLemon7-channelReceiver/TelemetryUnitremovedfromitscase.
Thisshowswhatthereceiverlookslikewithoutitscaseandidentifiesthevariousconnections.ThethreewhiteconnectorsfortheSatelliteandthetwotelemetryleadsareidenticalandnotallorientedthesameway.Norarethewiresallcolor-coded.Takespecialcaretofollowthelabelsonthecasewhenpluggingthemin,particularlythevoltagesensewire.Connectingthepackvoltagetothewrongpinwillalmostcertainlycausedamage.
LemonRx7-ChannelIntegratedTelemetryReceiver 5
PART 2. Using the Lemon Receiver/Telemetry Unit
A. Basic Requirements and Setup
Transmitter Toprovidebothradiocontrolandtelemetry,thisreceiverrequiresaSpektrumDSMXtelemetry-enabledtransmitter(seecurrentlistofcompatibletransmittersonpage2).
Itwillfunctionasareceiveronly(notelemetry)withawiderangeofotherSpektrumtransmittersandmodules,includingolderDSM2units,aswellaswithvariouscompatibletransmittersandmodules.
Thereceiveroperatesonlyat22mSframerateandwilloutput22mSframesevenifthetransmitterframeratehasbeenforcedinto11mSmode.
WithaDSM2transmitter,oraDSMXtransmitterinDSM2mode,thereceiverwillautomaticallyswitchtoDSM2whenitdetectsthebindsignal.
Instal lation Thereceivershouldbeinstalledusingnormalgoodpracticesfor2.4GHzequipment.Particularattentionshouldbepaidtothelocationandorientationoftheactiveportionofthedualantennas(thelast32mmofthecable,fromwhichtheoutersheathhasbeenremovedtoexposethewhiteinnercable).Thetwoantennasshouldberoutedsoastoachievewideseparationwiththeactiveportionsatrightanglestoeachother.
Theactiveportionsoftheantennasshouldbereasonablystraightforoptimumreceivingandtransmittingperformance,buttherestofthecablecanbecurvedgentlyasrequired.Thecoaxialcableusedforantennasisfragileandmustnotbekinkedorallowedtofloparoundorvibrateexcessively.
Theactiveportionsoftheantennasshouldnotbeimmediatelyadjacenttoconductiveitemssuchaswiring,ESC,batteryorcarbonfiberthatcouldblockthesignal(notethatnon-conductivematerialslikemostfoam,balsa,ply,etc.posenoproblem2).Theantennasshouldbelocatedsothatregardlessoftheattitudeoftheaircraft,atleastoneofthemhasaclearlineofsighttothetransmitter.Forexample,itisimportanttoavoidlocatingtheactiveportionsoftheantennaswherebothcanbeblockedsimultaneouslybythebatteryfromreceivingagoodsignal.SeeSection3C,page10forfurtherdetails.
Itisimportanttoconductarigorousreducedpowerrangetestbeforethefirstflight.Themodelshouldbeplacedonawoodentableorsimilarnon-conductivesupport.PutthetransmitterintoRangeTestmode(seetransmittermanual).Withthereceiverturnedon,walkawayabout25m(30paces)andthencirclethemodelwhiletestingcontrol.Ifthereareanyanglesatwhichcontrolisreducedorlost,gobackandreviewtheinstallation.
Iftelemetryisfunctional,theRSSIvalueshouldbemonitoredduringtherangetest;thiswillhelptoidentifyanyproblemswiththeinstallation(seesection3B,page9,foradditionalinformationonRSSI).
Atthebeginningofeachsubsequentflyingsession,doabriefreducedpowertestat25mtocheckthatallisworkingproperly.Thereisnoneedtorepeatthecirclingofthemodel.
2Somefoamplasticandheatshrinktubingisconductiveandcaninterferewithreception.Totestamaterial,zapitinamicrowaveovenforafewseconds.Ifitwarmsup,itshouldnotbeusednearthereceiverorantennas.
LemonRx7-ChannelIntegratedTelemetryReceiver 6
Power Requirements ThisreceiverrequiresahighervoltagepowersupplythanmostotherLemonreceivers,althoughitwillrecoverwellfrombrieflowvoltagebrownouts.EnsurethatunderloadyourBECorreceiverbatterydoesnotfallbelowthe4.5Vminimumatanytime.
Beawarethatsomecheap“3A”BECs,includingthoseinESCs,areoptimisticallyratedandcaneasilybeoverloadedbymultipleservosandotherhighdraindevicessuchasarefoundinsomemodernparkfliersize“ReadytoFly”aircraftequippedwithretracts,flaps,lights,soundsystems,etc.Some4.8VNiMHreceiverpacksalsohavelimitedcurrentcapabilityandmaydropvoltagesignificantlyunderload;besuretousecellsthatcandeliveradequatecurrentfortheloadplacedonthem.
B. Binding Bindingrequiresthatthereceiverbeputintobindmodefirstandthatthetransmitterthenbepoweredupinitsbindmode(seeyourtransmittermanualforspecificinstructions).
Procedure 1. Insertthebindplugintothefirstsetofpins(labeledBind/AUX2)withnopowerconnected
(Figure2.1).Ifasatelliteistobeuseditmustbeconnectedwhilebinding.
Figure2.1–Bindpluginsertedwithpowerdisconnected.
2. ProvidepowerviaESC,BECorseparatereceiverpack(heretheESCisconnectedtochannel1).Oncethebatteryisconnected,arapidlyflashingREDLEDbeneaththereceiver(andonthesatelliteifused)indicatesbindmode.Donotproceedtostep3unlessthelightisflashingcorrectly.
Figure2.2–Solidredlightonbottomofreceiverindicatessuccessfulbinding.
3. Turnonthetransmitterinbindmodeapproximately2metersawayfromreceiver.ThereceiverLEDshouldchangetoslowlyflashing,thentosteadyREDindicatingsuccessfulbind(seeFigure2.2).Ifyoudon’tgetasolidredlightonthereceiver(andsatelliteifused),seetheadvicebelow.
LemonRx7-ChannelIntegratedTelemetryReceiver 7
4. Fornormaloperationofthereceiver,removethepowerandbindplugatthispoint;ORTosetFailsafe(Section2C)orPPMmode(Section3A),leavepowerconnectedandbindpluginplace.
Binding Problems ItisnotunusualtoencounterdifficultiesbindingDSM-typereceivers,withthereceivereithercontinuingtoflashrapidlyorstartingthebindprocessbutneverattainingthesolidlightthatindicatesalink.BeingverysensitivetheLemonRXTelemetryReceivermaybealittlefussierthanusualaboutbindconditions.
Bindproblemscanusuallybeovercomebysimplyincreasingthedistancebetweentransmitterandreceiverduringbind.Eventhen,morethanonetrymaybeneededtoachievesuccess.Foreachtry,repeattheentiresequence,startingwithbothreceiverandtransmitterpowereddown.
Ifbindingfailsat2meters,startagain,movingfurtherawaybeforeturningonthetransmitterinbindmode,andhaveyourbodybetweenthetransmitterandreceivertoattenuatethesignalfurther.Whenbinding,stayawayfrommetallicobjects(suchascars,wirefencesandsteeltables),aswellasdampgroundandotherconductivesurfaces.WirelessroutersandotherWiFisourcescanalsoinhibitbinding.
C. Fai lsafe Failsafewillbeactivatedwheneverthereceiverisunabletoreceiveasignalfromitsboundtransmitterforaboutonesecond.Onceavalidsignalisagainreceivedthereceiverwillresumetransmittercontrol.
ThedefaultfailsafeactionifPresetFailsafeisnotusedisforthereceivertocutoffpulsesonallchannels.Thiswillcausemostmodernspeedcontrols(ESCs)toshutdownthemotorandwillleaveservoswherevertheyhappentobeatthemoment.Inthismode,thegreenlightisOFF.
WARNING:DefaultfailsafeisunsatisfactoryforIC(fuel)poweredmodels,astheenginewillcontinuetorunatthepowersetbythethrottleservowhenthesignalwaslost.
TheoptionalUserPresetFailsafe,indicatedbygreenlightON,providesspecificoutputsoneachofthesevenchannelsintheeventofsignalloss.PresetFailsafeisactivatedasfollows:
1. Forelectricmodels,removethepropeller(s)orotherwiseensurethatthemodelissafe.
2. Followthebindstepsfrom1to3.DONOTremovethebindplugorpoweratthispoint.
3. Adjustthetransmittersticks,switches,etc.forallchannelstothedesiredfailsafeoutputs.Formostpoweredmodelsthecriticalfailsafeactionistoensurethatthrottlegoestozero.
4. PresstheFailsafe/Modebuttonbriefly(lessthan1second).AGREENlightindicatesthatfailsafepositionshavebeenmemorizedandPresetFailsafeisenabled.Pressingthebuttonagainbrieflywilldisablepresetfailsafeandcausethegreenlighttoturnoff.
5. Testfailsafebyturningoffthetransmitterandverifyingthatallcontrolsgotothedesiredpositions.Usecare,asanerrorinsettingfailsafecouldcausethemotortostart,retractgeartoactivate,etc.Turnthetransmitterbackon,butnotethatthereceiverwillnotrecoverfromfailsafeuntilthetransmitterisagainfullyoperational,whichmaytakesometime(sodon’tdothistestintheair!).
Note:HoldingthebuttonformorethanaboutasecondwillactivatePPMmode,asindicatedbyablueLED(seeSection3A,page9).UnlessPPMmodeisrequired,longpressthebuttonagainandrepeatuntiltheblueLEDisOFF.Thenrepeatsteps3and4ofthepresetfailsafeprocedure.
Normally,failsafestatusandchannelsettingsareretainedbythereceiveruntildeliberatelyreset.HoweveritispossibletochangethesettingunintentionallyifanerrorismadewhilecalibratingthereceiverorsettingPPMmode.Alwayscheckthefailsafesettingaftersuchoperations.
LemonRx7-ChannelIntegratedTelemetryReceiver 8
D. Telemetry ThereceiverwillautomaticallytransmittelemetrytoaSpektrumtransmitterwithtelemetrycapability.Tomonitorthevariousparameters,thetransmitter’stelemetryoptionmustbeenabled:
o Receivervoltage.Automatic,noexternalsensororleadrequired.
o RSSI–signalstrength.Automatic.Displayedontransmitterunderparameter“A”.
o Temperature.Automatictransmissionofinternaltemperature.Formaximumaccuracy,however,theprovidedexternaltemperaturesensorshouldbeconnected.
o Batteryvoltage.Requiresaconnectiontothebatterypositiveusingthevoltagesensingwireprovided.Assuppliedthisisalreadycalibrated.ForrecalibrationofBatteryvoltage,seesection3E,page11.ThebatteryvoltagewireisnotneededifaV/Isensorisused.
HINT:AsimplewaytomonitorflightpackvoltagewithoutmodifyingthehighcurrentpowerwiringistoattachthevoltagemeasuringwiretothemostpositivepinoftheLiPobalanceconnector.
o Batterycurrent.RequirestheoptionalV/Isensorconnectedinthemainpowerlead.Thissensormustbepurchasedseparately.TheV/Isensorplugsinplaceofthesimplevoltagesensingwireandprovidesbothcurrentandvoltageinformation.
o RSSIout–RSSIisautomaticallydisplayedonthetransmitterscreen,butforusewithanOSD(OnScreenDisplay)usedwithanFPV(FirstPersonView)setuptheRSSIvalueisavailableonthesparewireoftheexternaltemperaturesensorcable.TheanalogvoltageoutputvariesinproportiontoRSSIfrom3.0Vdownto0Vasthesignaldiminishes.
WARNING:Donotplugthevoltagesensorcableintothetemperaturesensorsocket!Ifabatteryisattachedthisisalmostcertaintodamagethereceiver.
EnablingtelemetryinvolvesselectingeachfieldyouwanttodisplayintheTelemetrysetupscreenontheSpektrumtransmitter.ThefieldsavailableonthetransmitterscreenvaryalittledependingonwhichversionofAirwarethetransmitterisrunning.Volts,Amps,TempandRxV(plusRSSI,whichwillautomaticallyappearinthe“A”field)aretheonlyparametersthatcanbedisplayedusingthisreceiver.NotethatthePowerboxfieldsarenotactiveandthisreceiverthereforedoesnotdisplaymAhconsumed.
OntheSpektrumTelemetrysetupscreenthereisalistofnumberedfields.Thenameofthefieldindicatesthetelemetryparametertobedisplayedinthatfield(orindicatesitisEmpty).Usethescrollwheeltomovebetweenthefieldsandclicktoselectone.Youcanthenchoosewhatisdisplayed.ForthisreceivertherelevantchoicesareVolts,Amps,TempandRxV.Clickingafterselectingthedisplaywhiletheframeisstillflashingwilltakeyoutoasecondscreenwherevariousparameterscanbeset.ForexamplewithVoltsyoucanchoosewhetherthedisplayisActive,whetheraMinimumand/orMaximumvoltagealarmissetandwhattypeofalarmitis.TheoptionsavailablemaydependontheversionofAirwareyourtransmitterisrunning.
E. Connecting Servos or Fl ight Control ler ThereceiverisshippedinServoModewiththesignalforeachchannelavailableatthecorrespondingpin,asmarkedonthecase.Thisallowsservostobepluggeddirectlyintothereceiverintheusualway.
Tosupportanumberofthirdpartyflightcontrollers,thereceivercanbesettooutputaCombinedPPMsignal(cPPM),alsoknownasjustPPM,thatcarriesallchannelsonasinglewireconnectedtotheAUX1/PPMpins.SeeSection3A,belowfordetailsonsettingPPMMode.
PPMModeisindicatedbyaBLUElight,eitherflashingorsolid.ServoModehasnobluelight.
LemonRx7-ChannelIntegratedTelemetryReceiver 9
PART 3. Additional Information for Advanced Users
A. PPM mode TherearetwoPPMmodes,providingdifferentchannelorders:
o PPM-JmodeprovidescPPMinJR/SpektrumTAERchannelorder(SOLIDBLUELED)
o PPM-FmodeprovidescPPMinFutaba/HitecAETRchannelorder(FLASHINGBLUELED)
ThecPPMsignalprovidedbythereceiverincludeschannels1to7andisavailableontheAUX1/PPMpins.WhenthereceiverisinPPMmode,PWMsignalsarenotavailableforindividualservos.
ForareceiverinServomode(bluelightOFF),PPMmodeisselectedasfollows:
1. Followthenormalbindprocedurefromstep1tostep3(seesection2B,page6above).DONOTremovethebindplugordisconnectpoweratthispoint.
2. Pressthereceiverbuttonforabout2seconds,untiltheFLASHINGblueLEDcomesON,indicatingPPM-Fmode(AETRchannelorder).TochangetoPPM-Jmode(TAERchannelorder)pressthebuttonagainforabout2seconds,untiltheSOLIDblueLEDcomesON.
3. Whentheappropriatestatusisachieved,disconnectthepowersourceandremovethebindplug.Thereceiver(evenifre-bound)remembersthesettinguntilitisdeliberatelychanged.
IfthereceiverisalreadyinPPMMode(bluelightONorFLASHING)themodecanbechangedorcancelledbyfollowingtheaboveprocessuntilthedesiredstateisachieved.
NotethatasatellitereceivercannotbeusedwhenthemainreceiverisinPPMmode.
B. RSSI TheRSSI(ReceivedSignalStrengthIndicator)numberissentbackfromthemodelbytelemetryanddisplayedinthe“A”fieldonthetransmitterscreen.Itrepresentsthestrengthoftheradiocontrolsignalavailablefromthereceiverfrontendforcontrolofthemodel.Itshouldreadcloseto100whenthereceiverisnexttothemodelandwilldropwithdistanceuntil,atavaluetypicallyaround30,thetelemetrysignalisnotstrongenoughandthedisplayfreezes.Thereceiverhasexcellentsensitivityandwillcontinuetooperatereliablywellbeyondthispoint.Indeed,LemonrecommendanRSSIreadingofnolowerthan20forsafeoperation,givinganideaofthemarginofsafetyinvolved.
Figure3.1–AnRSSIvalueof74displayedonaDX8screeninthe“A”field.
LemonRx7-ChannelIntegratedTelemetryReceiver 10
Theverticalbarsymbolinthetopleftshowsthattelemetryisliveandisbeingreceived.
WhileRSSIvaluesbelowabout30areunlikelytobeseenonthetransmittertelemetryscreen,theRSSIvoltagedisplayedonanOSD(On-ScreenDisplay)maycontinuetobevalidatmuchlowerlevels,asthisformofdisplaydoesnotrelyontherelativelylowpowertelemetrytransmissionfromthereceiver.
ChangesintheRSSIreadingcanbeconvenientlyexploredwiththetransmitterinRangeTestmode.NotethatputtingaSpektrumtransmitterintoRangeTestmodeattenuatesoutputpowerenoughtoreducerangebyafactorofabout30.3Thuseffectivecontrolat35m(120feet)inRangeTestmodeshouldtranslatetoabout1km(3600feet)rangeatfullpower.Thereare,however,manyvariablesinvolved,sotreatthisasonlyaroughguide.Thereisaverygoodprobabilitythatyouwillgetmuchgreaterrange.
TheLemonRSSInumberisarelativevalueandcannotbedirectlycomparedtoothersignalindicatorssuchasantennafadesreportedbySpektrumortheFrSkyRSSInumber.LemonhasstatedthatthemaximumsignalmeasuredaftertheLNAfrontendwhenthetransmitterandreceiverarerightnexttooneanotherisdisplayedasavalueof100.Adropin“RSSI”byoneunitcorrespondstoadropinsignalstrengthofapproximately0.6dBm.AttheLemonrecommendedminimumreadingof20thesignalistherefore0.6x80=48dBdown.Whilethereceiverhasalotofreservesensitivityandshouldcontinuetoworkevenbeyondthatpoint,itisnotrecommendedthatthisbetakenforgranted.
TestsinpracticalsituationsshowafairbitoffluctuationintheRSSIvalue(causedpresumablybychangingmodelandtransmitterorientationamongotherfactors),butitappearsthevaluefallsfairlysteadilyandapproximatelylinearlyfrom100to50thendropsoffmoreslowlybutstillinalinearfashionwithdistanceuntiltelemetrycutsoutatavaluearound30.
C. Antennas and Satel l ites ThisLemonreceiverisdescribedasfullrangeforbothcontrolandtelemetry.InfactthisreceiverhasaparticularlysensitiveLowNoiseAmplifier(LNA)frontendandshouldbettertherangeofothercomparableDSM2/DSMXreceiversunderthesameconditions.Howeverrangeisaffectedbythenumberofaerials(antennas)andtheirorientation,aswellasbytheinstallationinthemodel.
Thisreceiverhastwoactiveaerial(antenna)wires(thelast32mmofthecables)connectedtoaswitchthatselectsthestrongeravailablesignal.Thereceiverwillswitchantennasveryquicklyiftheoneitisusingstartstodropinsignalstrengthbelowtheotherantenna.Theswitchwilloccurwithin300mSandnosignalislostduringtheswitchingperiod.ThisantennaswitchingstrategyiscommonlycalledintheRCworld“Diversity”.
Thereceiveralsohasaconnectortoallowtheuseofasatelliteforadditionalsignalrobustness.Asatellitedoesnotincreasethemaximumpossiblerange.Rather,asaseparatestand-alonereceiveritincreasestheprobabilitythatareliablesignalwillbeobtainednomattertheorientationofthemodel.Themainreceiverselectsthestrongerofitsownbestsignalorthatofthesatellite.Notethatsatelliteswithdiversityantennasarenowavailable,givinguptofourseparatesignalsourcesforthereceiver/satellitecombination.
Theantennasweuseforradiocontrolradiate(andreceive)inalldirections,butthesignalismuchweakerofftheendsoftheantenna(theactiveportionofthecable)than"broadside"toit.Thinkofan
3Sincerangeisrelatedtothesquareofpower,toreducerangebyafactorof30requiresacutinpowerbyafactorofabout900.Rangetestpoweristhustypicallyaround0.1mw.
LemonRx7-ChannelIntegratedTelemetryReceiver 11
ancientnavalbattlewheretheshipshadverylittlefirepowerforeandaftbecausemostoftheircannonwerepointedoutthesides.
Toachievethemostreliablepossiblelinktothemodel,therefore,whatwewanttoavoidaresituationsinwhichthetransmitterandreceiverantennasareend-ontoeachother.Forthetransmitter,theadvicetothepilotissimple:don'tpointtheantennaatthemodel.Forthereceiver,thingsaremorecomplicatedbecausethemodelisconstantlychangingitsorientationinrelationtothetransmitter.Asinglereceiverantennawillinevitablybepointedatthetransmittersomeofthetime.
Thisiswherediversitycomesin.Ifthereceiverhastwoactiveantennaspositionedatrightanglestoeachother,theycanneverbothbepointedatthetransmittersimultaneously.Thereceiverjusthastoselecttheantennathatisgivingthebettersignalrightnow.That'swhatdiversityswitchingdoes.
DiversityimprovesthereliabilityoftheRFlinkinotherways.Ifthetworeceiverantennasarewellseparated,atleastoneshouldhaveaclearviewofthetransmitter,minimizingtheriskofsignalblanking.Aswell,withantennasatrightanglesoneofthemshouldberoughlyparalleltothetransmitterantenna,thusaligningpolarizationforastrongersignal.
Conductivematerialssuchasfoilcoverings,batteries,metalcomponentsandcarbonfibercanabsorbandshieldtheincomingradiosignal.2.4GHzsystemshaveaveryshortwavelengthandaresusceptibletothis.Receiveraerialsneedtobeplacedsothatthiseffectisminimized.
Whatallthismeansfortheinstallationofthereceiverissimple.Makesureitstwoantennasareseparatedasfaraspracticalfromeachotherandfromconductivestufflikebattery,wiringandcarbonfiber,andkeeptheactiveportions(thelast32mm)reasonablystraightandatrightanglestoeachother.
Ifasatelliteisconnectedforadditionaldiversity,itshouldbewellawayfromthemainreceiver,notrightnexttoit.Alignitsothesatelliteaerial(s)andatleastonemainreceiveraerialareatrightangles.
Don'tgetparanoid.Theinstallationdoesn'thavetobeperfecttosupportanadequatelystrongRFlink.Ourmodernreceiversdoaremarkablygoodjobofpickingupthesignal,evenwithjustasimplesingleantenna,sodiversitycanbethoughtofasextrasecurityforwhenthegoinggetstough.
D. Power Considerations Thistelemetry-integratedreceiverdrawsapproximately75mAwithnoservosconnected,asomewhathighercurrentthananormalreceiver.Forcomparison,theLemonDSMXCompatible7ChannelStabilizedReceiverdrawsabout55mAandtheLemonDSM2Compatible6ChannelFeatherLightReceiverdrawsabout25mA.Moreimportantly,theminimumoperatingvoltageoftheTelemetryreceiveris4.5Vcomparedto3.45VforotherLemonreceivers.ThismeansthatthisreceivercannotbeoperateddirectlyfromasingleLiPocellasusedinsomeDLGapplicationsbutmustuseeitheravoltageboosterorahighervoltagepack.
GivenLemon’srecommendedupperlimitof7.4v,thereceivershouldnotbepoweredbya2sLiPobattery(8.4Vfullycharged).AfourorfivecellNiMHbatteryora2sLiFebatterycanbeused.
E: Voltage Recal ibration Thereceiverispre-calibratedforvoltagesensingandavoltagesensingwireisprovidedasastandarditem.IftheoptionalV/Isensorisused,thevoltagesensingwireisnotrequired(seeSection3F,below).
Re-calibrationoftheexternalvoltagesensingofthereceiverisnormallynotrequired,butifitbecomesnecessary,pleasefollowtheprocedurelistedbelow.
LemonRx7-ChannelIntegratedTelemetryReceiver 12
Figure3.2–VoltagesensorwireconnectedtobatteryV+.Firstbindplugisinnormalverticallocation,secondisinsertedhorizontallybetweenthetop(signal)pinsofAileronandRudderchannels.ThedevicewithascreenisaWattmeter,whichmeasuresvoltageandcurrentandisusedtoconfirmthebatteryvoltage.
Figure3.3–Batterynowpluggedin.Notevoltagesensorwire.Voltagesensoriscalibratedat8.43V,asshownonWattmeter.
Procedure 1. First,verifythatbothblueandgreenlightsonthereceiverareOFF.Ifnecessary,gobacktothe
instructionsforFailsafe(page7)orPPMMode(page9)andreset.
2. Withnopowerconnected,insertabindplugverticallyatbindlocation,asinthenormalbindprocedure.Insertasecondbindplughorizontallybetweenaileronandruddersignalpins(topones).
3. Connectthevoltagesensingwiretoan8.4Vsource.Afullychargedtwo-celllithium-polymer(LiPo)batterywillprovideanadequatelyaccuratereferencevoltage.SeeFigures3.2and3.3.
LemonRx7-ChannelIntegratedTelemetryReceiver 13
4. Withthetwo-cellbatterydisconnected,connectaspeedcontrol(ESC)withintegralBECtothereceiver.4Anyavailableservopinscanbeused(centerpinispositive,lowerpinisground).
5. ConnecttheESCtothetwo-cellLiPobattery.TheREDlightshouldbeflashingrapidlybeneaththereceivertoindicatebindmode.
6. Turnonthetransmitterinbindmodeapproximately1-2metersawayfromthereceiver.Thereceivershouldchangefromslowlyflashingtosteadyred,indicatingasuccessfulbind.Makesuretransmittertelemetryissetuptodisplaybatteryvoltage.
7. Pressthereceiverbuttonbriefly(lessthan1second).AGREENlightmeansthatthevoltagereadingiscalibrated.Thetransmittershoulddisplay8.3Vor8.4Vasbatteryvoltage.5
8. Pressandholdthereceiverbuttonforabout1.5seconds,untiltheBLUElightisturnedon.Thisindicatestothereceiverthatcurrentsensingisnotavailable.6
9. Turnoffthereceiverandremovebothbindplugstocompletevoltagecalibration.7Ifnecessary,resetFailsafeand/orPPMModetosuityoursetup.
F: Cal ibrating the Optional V/I Sensor TheLemonRxV/Isensingmoduleprovidesbothbatteryvoltageandcurrentsensing.ThereceiverisNOTpre-calibratedforusewiththeV/Imodule.ThefollowingcalibrationprocedureneedstobedoneoncewithanynewV/Isensorbeforeuse.Anadequatecalibrationcanbeperformedwithatwo-cellLiPobatteryandWattmeter.
Figure3.4–V/IsensorconnectedtobatteryV+withtwobindplugsinserted.ThedevicewithascreenisaWattmetertoconfirmtheactualbatteryvoltageandcurrent.
4Astand-alonebatteryeliminator(BEC/UBEC)orsuitablebatterycanalsobeusedtoprovidethenecessary4.5to7.4vpowerforthereceiver.5Notethat8.39vwilldisplayas8.3vbecauseofthelackofaseconddecimaldigitintheSpektrumtransmitterdisplay.Themoreprecisevalue,however,isusedinternallyandcanbeloggedontheSDcard.6IfthebuttonisreleasedbeforetheblueLEDcomeson,brieflypressthebuttonafewtimesuntilthebluelightisOFF.Thenstartsetupagainatstep7.7Ifcurrentmeasurementisrequired,itisnecessarytopurchasetheoptionalV/Isensor(seeSection3F).
LemonRx7-ChannelIntegratedTelemetryReceiver 14
Figure3.5–V/Isensorcalibratedat8.4Vand4A,asshownontheWattmeter.
Procedure 1. First,verifythatbothblueandgreenlightsonthereceiverareOFF.Ifnecessary,gobacktothe
instructionsforFailsafe(page7)orPPMMode(page9)andreset.
2. Withnopowerconnected,insertabindplugverticallyonthebindpins.Insertasecondbindplughorizontallybetweenaileronandruddersignalpins.
3. ConnecttheV/Isensortoafullychargedtwo-cellLiPobatterytoprovidethenecessary8.4Vsource.8Figure3.5showsthemeterconnectedinseries.Itmustbeabletomeasurecurrentofatleast5A.
4. Todrawanappropriatecurrentforcalibrationofthesensor,connecttheESCtoabrushlessmotorthatisknowntodrawmorethan4amps.Itmaybenecessarytoinstallapropelleronthemotortocreatethenecessaryload–beVERYcarefulifthisisdonetoensurethatthemotorissafelymounted.Besuretodisconnectthemotorwhenfinishedcalibration.
5. ConnecttheESCtothereceiverthrottlechannelpins.IftheESClacksaninternalBEC,aseparateBECcanbeusedtoprovidereceiverpower.
6. ConnecttheESC(andseparateBECifused)tothebattery.CheckthattheREDLEDbeneaththereceiverisflashingrapidlytoindicatebindmode.
7. Turnontransmitterinbindmodeapproximately1-2metersawayfromthereceiverwiththethrottlestickatlow.Thereceivershouldchangefromslowlyflashingtosteadyred,indicatingsuccessfulbind(seepage6fordetails).Makesuretransmittertelemetryissetuptodisplaybatteryvoltageandcurrent.
8. Pressthereceiverbuttonbriefly(lessthan1second).AGREENLEDmeansthevoltagereadingiscalibratedandcurrentsensingbiasissetat0A.Thetransmittertelemetrypageshoulddisplayeither8.3Vor8.4Vasbatteryvoltage9and0Aforcurrent.
8Thebatteryneedstobeabletosupplya4Acurrentwithoutunduevoltagedrop.Itisrecommendedthatthebatterybeatleast1000mAhwithatleast20Crating.
LemonRx7-ChannelIntegratedTelemetryReceiver 15
9. Movethethrottlesticktostartthemotor(becareful!)andadjustuntilthecurrentdrawshownonthemeterisascloseaspossibleto4.0A.
10. PressandholdthereceiverbuttonuntiltheBLUELEDturnson,indicatingthatcurrentsensingiscalibrated.10
11. Withthesystemstilldrawing4A,checkthatthetransmittertelemetrypageshowsacurrentreadingof3or4A.11
12. Turnoffthereceiverandremovebothbindplugstocompletevoltageandcurrentcalibration.Ifnecessary,resetFailsafeand/orPPMModetosuityoursetup.
HINT:Calibrationcanbedoneintwoparts.Thereceiverremembersthecurrentcalibrationvalueevenifyoudothevoltagecalibrationsubsequently.
Firstcalibratethecurrentvaluewithaconstant4Aload.Anybatteryfrom2sto6sthatiscompatiblewiththemotorandESCcanbeused.Gothroughsteps1to6,skipstep7,thencompletesteps8to10.
Nextdothevoltagecalibrationasinstep7,usingeithera2sbatteryoravariablevoltagesupply.
Finallygotostep11tocompletethecalibrationprocess.
G. Creating and Reading Telemetry Log Fi les Spektrumtelemetry-enabledtransmitterscanrecordalogfileofthedatasenttothetransmitterfromthereceiver.Thisiscontrolledentirelybythetransmitter;nosetupisrequiredonthereceiver.
Theoptionsavailableatthetransmitterspecifywhetherrecordingisenabled,ifso,howitistobestarted,andthenameoftheresultingfile.Refertoyourtransmittermanualforspecificinstructions.Youmaywanttoassignaswitchtostartandstoplogging,oryoumayprefertohaveitstartautomaticallyassoonasthethrottleisadvanced.
ThelogfilesaresavedontheSDcardinthetransmitter,alongwiththevariousmodelsetupfiles.Thelogfileshavethesamenameasthemodelfilesbutanextensionof.TLMratherthan.SPM.ToreadSpektrumlogfilesyouneedaprogramspecificallydesignedforthepurpose.Youcurrentlyhavetwochoices:
1) TheofficialSpektrumapprovedandsupportedSpektrumTelemetryViewersoftwarewrittenbyROBOSoftware.ItisavailableforbothWindowsandMac(OSX)andisavailableasa30daytrialandtopurchaseforUS$19.99here:http://www.robo-software.com
2) TheexcellentTlmviewerprogramwrittenbymodelerMikePetrichenko.ThisisafreeWindows-onlyprogramandavailableat:http://www.tlmviewer.com
HereisanexampleofaflightlogfromtheLemonreceiver,readandgraphedbyTlmviewer,showingthepackvoltageandcurrentduringa9-minuteflightofa1.8mspanelectricglider.
9Notethat8.39vwilldisplayas8.3vbecauseofthelackofaseconddecimaldigitintheSpektrumtransmitterdisplay.Themoreprecisevalueisusedinternallyandcanbelogged.10IfthebuttonisreleasedbeforetheblueLEDcomeson,brieflypressthebuttonafewtimesuntiltheblueLEDisoff,andthenstartPPMsetupagainatstep7.11Notethat3.9Awilldisplayas3AbecauseofthelackofaseconddecimaldigitintheSpektrumdisplay;this1Aprecisionisampleformostpurposes.Themoreprecisevalueisusedinternallyandcanbelogged.
LemonRx7-ChannelIntegratedTelemetryReceiver 16
Figure3.6–Tlmviewergraphofvoltage(green)andcurrent(orange)inflight.
ThisisthegraphofRSSIvaluesforthesameflight,whichwasouttoareasonablevisualrangelimit.
Figure3.7–TlmviewergraphofRSSIfromaproperlyinstalledreceiver.
NotehowthereareoccasionalplaceswheretheRSSIdropstozero.Thiswillbewherethetelemetrylinkwasmomentarilylost.HowevertheRSSIvaluerarelyfallsbelow50whenthedataisavailable.
FinallyhereisthesametypeofgraphfromasimilarflightwherethereceiverwaspoorlyinstalledwiththetwoantennaslyingalongsidetheLiPoandeasilyblanked.
LemonRx7-ChannelIntegratedTelemetryReceiver 17
Figure3.8–TlmviewergraphofRSSIfromapoorlyinstalledreceiver.
ThistimetheoverallRSSIvaluesarelowerandtherearenotonlyzerovaluesbutsignificantperiodswherethedataisobviouslymissingandthegraphingprogramhassimplyjoinedthevaluesateachendofthegap.Anexampleisbetween5:00and5:30min.Althoughthereareperiodswherethetelemetrytransmissionbacktothetransmitterhasfailed,theactuallyRSSIatthereceiverisstillstrongascanbeseenfromthevaluesjustbeforeandjustafterthetelemetrygap.Theweakertelemetryconnectionfromreceivertotransmitterhasbeenaffectedmuchmorebythepoorinstallationthanthecontrolconnectionfromtransmittertoreceiver.Thisisfurtherevidenceofthesensitivityofthereceiverandtherobustnessofthecontrollink.
Finally,Figure3.9showsexactlythesamedataexportedfromTlmviewerasa.csvfileandthenimportedintoMicrosoftExcel(whichallowsyoutomanipulatethepresentationformateasily)anddisplayedasapointscattergraph.Notethatdisplayingthedatathiswayshowsupthegapsinthetelemetrydatafeedwhenthemodelwasatextremerange.Acoupleofexamplesofsuchgapsarehighlightedinblueonthex-axis(whichExcelhasplottedinunitsof1/100secratherthanminutes).
Figure3.9–ExcelgraphicdisplayofpoorRSSIreadings(samedataasFig3.8).
LemonRx7-ChannelIntegratedTelemetryReceiver 18
H. Servo Output Timing
Most users can ignore this sect ion. This is technical information for those who need it . Thissectionisabouthowthereceiverputsouttheinformationforthecontrolchannels:allsevenatonce,oneaftertheother,orinsomedifferentmanner.
PWM InnormalPWM(PulseWidthModulation)mode,wheretheoutputforeachservoispresentonseparatepins,theLemonreceiverputsoutchannelpulsesintwobatches:
FirstChannels4,5and6–thatisRudder,GearandAux1–areoutputsimultaneously.
Then2.4mSlaterChannels1,2,3and7–Throttle,Aileron,ElevatorandAux2-areoutputtogether.
ThiscanbeseeninthelogictracedisplayshowninFigure3.10.NotethatChannel0onthelogictraceischannel1fromthereceiverandsoon.Thevaryingwidthofthepulsesthatrepresentscontrolinformationisclearlyvisible,withthefirstchannelneutral,thesecondatmaximum,andsoon.
Figure3.10–Logictracesofthe7outputchannelsfromtheLemonTelemetryreceiver.
Thisoutputschemeisdifferentfrommanyotherreceivers.ThemajorityoflowcostDSM2/DSMXreceiversoutputthechannelsoneafteranother(sometimesdescribedas“roundrobin”),butsomehigherendreceiverssynchronizeallorsomeofthepulsestoensuresimultaneoussignalsforservoactionsthatshouldoccuratthesametime.
Theadvantageofsimultaneoussynchronizedpulseoutputsisthatallservoactionsareinitiatedtogether.Theresultmaybenoticeableindemandingprecisionapplications,particularlyhelicopterrotormovements.Howevertheremaybeadownside,dependingontheservosused.Analoganddigitalservosloadthepowersupplyinadifferentway.Digitalservosarerefreshedatfixedintervals,withnoreferencetothetimingofincomingpulses.Thepowerpulsesaresentathighfrequencycomparedwiththeincomingcontrolpulses.Sotheyalwaysdrawpower,butatafairlyconsistentlyrate.
LemonRx7-ChannelIntegratedTelemetryReceiver 19
Bycontrast,analogservosonlydrivethemotorwhentheygetapulse,andtheydoitassoonastheygetthatpulse.Ifthecontrolpulserequirestheservotomovesignificantly,theresultmaybeademandforfullcurrent.Duringaggressiveflyingit’spossibleforseveralservostobecalledontochangepositionatthesametime,creatingahugedemandonthepowersupplyatthatinstant.
Theresultofthisdifferenceinfunctioningisthatonaveragethetotalcurrentforanalogservosmightbelowerthanforequivalentdigitals,buttheinstantaneouscurrentdrawcouldbeveryhigh.Itisthispeakcurrentthatcandepressthevoltageand“brown-out”thereceiver.
Inpractice,pulsetimingcanbeignoredbymostusers.However,forthoseseekingsimultaneouscontrolactionorsettingupanalogservosinlargemodelsandotherswithheavyservoloadsitisimportanttounderstandtheimplicationsofdifferentoutputtimingschemes.
cPPM Bydefinition,acPPMstreamconveysthecontrolpulsesinsequence.TheLemonTelemetryreceiveroffersachoiceofJR/Spektrumchannelorder(TAER)orFutaba/Hitec(AETR).
Figure3.11showsthecPPMstreamattheAux1/PPMpinonthereceiver.TheexamplehereisinFutaba/Hitecchannelorderandhaschannels1,5and6approximatelyatneutral,channel2atminimumandchannels3,4and7atmaximum.
TheLemonTelemetryreceiveroutputsonly7channelsonthePPMstream.SomeotherPPMreceiversoutputmorechannelsoncPPMthantheyactuallyhavePWMpins.
Figure3.11–OscilloscopetraceofcPPMoutput.
Note:Thisgraphisincludedsolelytoshowthenumberofchannelsanddisplayssomesignaldistortionduetomeasurementlimitations.Disregardthevoltagelevelsseenhere,aswellasthenoiseandovershoot.Aclean,noise-freehigh/lowpulseistobeexpectedfortheactualoutput.
LemonRx7-ChannelIntegratedTelemetryReceiver 20
NOTICE
ThismanualisprovidedtohelpyouunderstandandusetheLemonRx7-ChannelIntegratedTelemetryReceiver.TheauthorsarenotassociatedwithLemonRxandthisisnotaLemonRxpublication.
Youcanfreelyquotefrom,redistributeand/ormodifythismanual;indoingsopleaseacknowledgethesourceandanychanges.
Themanualisdistributedinthehopethatitwillbeuseful,butWITHOUTANYWARRANTY;withouteventheimpliedwarrantyofMERCHANTABILITYorFITNESSFORAPARTICULARPURPOSE.SeetheGNUGeneralPublicLicenseformoredetails.Inusingthismanual,youagreethatyouacceptallresponsibility.
Formoreinformation,see
http://www.rcgroups.com/forums/showpost.php?p=29707169&postcount=1
http://www.lemon-rx.com/shop/index.php?route=common/home
JJ604andDaedalus66
January2016
LemonTelemetryRxManualFeb9