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Help! FT Gremlin/SPM4650 SRXL2 RX Help

CustomRCMods

Well-known member
#1
Hey guys - Just picked up a gremlin off @Grifflyer, looking for some assistance setting it up with my Spektrum SRXL2 Rx. It doesn't pop up in the protocol drop down in betaflight, and I cant get the RX to talk to the FC Properly. It is wired up correct and binds to my dx6 just fine. Im a veteran in the FB planes but quads are completely new to me. Please help!
 

CustomRCMods

Well-known member
#3
Looks like there is exactly one version of Betaflight that supports SRLX2 on the Femto F3 board - https://github.com/SpektrumRC/betaf....0.3-SRXL2/betaflight_4.0.3_SPRACINGF3EVO.hex

You'll have to download and flash that as support for F3 boards was dropped in BF 4.1, which is when support for SRXL2 was fully added.
Thank you, so I download that then flash it on the board by shorting the boot pads, and I should be good? okay. I will try it and report back.
 

ElectriSean

Eternal Student
Mentor
#5
You are setting Receiver Mode to Serial, correct? It should then have an option for SPEKTRUM2048/SRLX in the Serial provider list. I can't see it not being there, as that was Spektrum's github you downloaded from.
 

CustomRCMods

Well-known member
#6
You are setting Receiver Mode to Serial, correct? It should then have an option for SPEKTRUM2048/SRLX in the Serial provider list. I can't see it not being there, as that was Spektrum's github you downloaded from.
Yep, all the beta flight settings are proper, even used the SRXLv2 CLI commands mentioned in their setup video and on the github page. I’m dumbfounded, after a little research seems like I’m not alone. hm.
 

ElectriSean

Eternal Student
Mentor
#7
A simple and cheap solution would be to get a LemonRx satellite and save your SRLX for a later build with a newer FC. I'm actually surprised there is no backwards compatibility in that Rx.
 

CustomRCMods

Well-known member
#8
A simple and cheap solution would be to get a LemonRx satellite and save your SRLX for a later build with a newer FC. I'm actually surprised there is no backwards compatibility in that Rx.
I’ve got a boatload of lemon satellites actually, may drop one of those in. I also have a SPM 4648 from ebay on the way which will probably be the best stress free alternative for this project. thanks for the input! disappointing but i’m pretty sure this won’t be my last quad.
 

ElectriSean

Eternal Student
Mentor
#9
I’ve got a boatload of lemon satellites actually, may drop one of those in. I also have a SPM 4648 from ebay on the way which will probably be the best stress free alternative for this project. thanks for the input! disappointing but i’m pretty sure this won’t be my last quad.
There's always 1 more... lol