User Manual

JJ604
3
AddingFrSkytoaSpektrumDX8
3
AddingFrSkytoaSpektrumDX8
TheFrSky2.4systemispopularbecauseofitsextremelyreliableradiolinkandgrowing
rangeoftelemetryoptionsatareasonableprice.Theycurrentlymakepluginmodulesfor
suitablemodulartransmittersplustwoaddonDIYmodulesthatcanbeinstalledinternally
(DTH)orexternally(DTHU)on
anytransmitter.
AddinganinternalonetoaSpektrumDX8isattractiveandisstraightforwardenough
foranyonewhocansoldertwowirestogetherandmakesnochangestotheDX8atall,
exceptafewholesinthebackcover.
IreallylikehavingthepoweroftheDX8software
andprogramming(andSDcard
storage!)togetherwiththelinkreliabilityoftheFrSkyanditsversatilecheaptelemetry.
LeavingtheDX8intactmeansIcanhaveFrSkyorDSM2/DSMXattheflickofaswitch,
whichisnicefortheSpektrumbricksandparkflierswithcheapieOrangeDSM2receivers.
Yougetthebestofbothworlds.Theonlythingyoudon’tgetintheaddonistheModel
MatchfacilitysincethisisafunctionoftheSpektrumDSM2/DSMXconnectionbut
everythingelseintheDX8appliestotheFrSkylink.
TheFrSkyunitisinstalledusingjust3
connections:powerandgroundplusthePPM
controlsignalfromthetransmitterencodersection.TheDX8shouldbeasimpleconversion
sincethePPMsignalisavailableatthetrainerjackontheback.TheDX8doesnotprovide
suitablepoweratthechargerportbutitisasimple
jobtoaddanotherconnectortothe
batterypack.Unfortunately ifyouconnectitupasexpected(seeConnections),itdoesn’t
work.
1. IfoundplentyofinformationonconvertingothertransmittersbutlittleontheDX8.
TherearetwospecialproblemswiththeDX8thatdonotoccurwithmost
transmitters.
Itusesa4.8VbatteryandtheFrSkymodulespecifiesaminimumof6V
2. DespitebeingcleveraboutrecognizingPPMpulsepolaritytheFrSkymoduledoes
notrespondtotheDX8output.
ShortAnswerforelectronicstypes
Adda47kpulldownresistorbetweenthePPMleadandgroundandsupplytheFrSky
modulewithaminimumof6V.Minewillactuallyworkdownto4.9Vbutlessthan6Visat
yourownrisk.
LongAnswer
Thevoltageproblemcanbesolvedinanumberofways.Seepost#3foradiscussionof
fouroptions.
Irecommendthesimplestandmosteffectivesolutionofreplacing thenormalDX84.8V