Using SPI receivers with an ACCESS/ACCST LBT/EU radio

Going on for around a year ago, I made a YouTube video to provide a small tutorial on how to enable D8 on an LBT radio. Typically, your Taranis X9D or QX7 radios.



Since that time, FrSky developed their ACCESS protocol, and the radios that support it, don’t support the D8 protocol. In fact, in FrSky’s seemingly endless efforts to make us hate them, originally these radios didn’t support D16 either, although this was hastily added on later.

You will probably know if you have one of these radios as they’ll have a big “Access” logo on display. But typically you are looking at the X9 Lite, Xlite Pro, X7 Access and the X9D Plus 2019 edition. So what do you do if you have one of these radios on LBT and you want to fly an SPI based quad (typically a whoop style)

For people on FCC, their choice is easy, you choose the FRSKY_X option in Betaflight, bind up and you are away. Previously I’ve advised against running D16 on SPI, but improvements have been made and if you are up to data on Betaflight you should have a good experience.

On LBT, it’s simply not going to bind though. But you do have a few options, 3 to be precise.

1: A Multiprotocol Module

A multiprotocol module gives you a lot of cool features, pretty much the ability to bind to almost anything from your radio and fly it with all the normal settings, switches and rates you have on your radio. Got one of those little toy quads with the awful tiny remotes where the tiny sticks don’t allow any precise movement? Then a multiprotocol module will fix it. They will also allow you to use D8 mode, as well as D16 in both FCC and LBT modes.

I reviewed one of these modules from URUAV a few months ago, which had a problem that needed to be fixed by a updating the bootloader. Not a trivial fix, but there are other Multiprotocol modules on the market which don’t seem to suffer this issue, like the iRangeX version.



2: Use FRSKY_X_LBT

Previously, the FRYSKY_X_LBT SPI protocol didn’t exist, but coming in Betaflight 4.0 (I think – I couldn’t pin it down to the absolute release) you’ll have the option in the SPI dropdown to pick this protocol instead of FRYSKY_X (the FCC version) This will bind on D16 on an LBT radio and you can get on and fly.



The only issue comes if you have whoops on 3.x.x versions of betaflight and you don’t necessarily want to upgrade. What then ?

3: Instantly toggle between LBT/FCC with a simple LUA script

If you browsed through the FrSky firmware releases for various radios, you might notice that for the original QX7 or X9D there are FCC or LBT versions of the firmware for the internal XJT module. Look at an ACCESS radio and there is no such firmware The region will be set and be dependant on where you purchase the radio from.

Look beyond this and you might notice a few references that suggest it can be changed if you contact them, or your dealer. If you do this then you might get your hands on a simple little LUA script that can instantly and very easily toggle your radio between FCC and LBT. Not sure where to get it, well here’s a copy of it to download and install on your radio.

IRSM LUA Script

I dropped the LUA script in the tools directory of my radio, this makes it accessible from the tools section and slightly easier to navigate to and run.



From here, you can just scroll between the two settings. You don’t even need to hit enter to select one. Just land on the one you need and exit the script and you’ll be in that mode. The only restriction I’ve noticed is that you need to be in a model where the internal module is activated. If you try this from a sim, the script will be unable to detect your current setting,



As it says: “Check your country law” – it’s worth pointing out that depending on the country you reside in, it may be illegal to fly on the other standard. I’ll leave you to wrestle with that yourself and ponder how flying around your own house with a tiny whoop could ever be detected and involve the police breaking down your door and slapping the cuffs on you 😀

A word about ACCST D16 v2

FrSky recently dropped a press release telling everyone they should upgrade to ACCST D16 v2. They cited fixes to the previous version of the protocol…. you know, the one we’ve all been running for the last 6 years or so without any problem. You can see their press release here.

All I can say about this is: Don’t install it. This is nothing but a poorly designed bit of fear-mongering designed to move people onto their new v2 protocol which is encrypted and makes it impossible to bind to any 3rd party receiver. Those 3rd party receivers include SPI receivers working in D16 mode .

If you really feel you must install it (why?) then you’d need to use D8 mode in an SPI receiver. If you have an older non-Access radio, this is fine, but on the new Access radios you’d have to use a multiprotocol module.

I can only guess that FrSky were becoming worried that people didn’t dislike them enough, so wanted to give their users the final push over to Jumper instead!

11 thoughts to “Using SPI receivers with an ACCESS/ACCST LBT/EU radio”

  1. Thanks for the info!, ordered taranis qx7 2019 access eu lbt…
    I have an eachine novice 3 on route and was hoping there would be a way to bind!!.
    One question If I may.. maybe stupid..
    If I were to just install xm+ mini on quad with same firware as radio, would that bypass the non eu frsky firmware on quad and work? Many thanks

    1. Sorry for the dealy first off – I switched hosting companies, and my email alerts aren’t working. The quick answer is yes – by using an XM+ you are just going to be using D16 mode in whatever you have installed on the radio and you’ll be sorted

  2. Thank you so very much for this. Still haven’t quite managed to get my little Mobula 6 to work with EmuFlight’s Frsky_X (no X_LBT option…), but haven’t torn ALL my hair out just yet.

    I did have an “All Binding” Jumper T16 v2 up until about 6 hours ago when I sent it back. Just problem after problem… Holding out for the T18 and fingers crossed it will be less riddled with bad luck when it reaches my hands. At which point the taranis becomes a spare, mainly for all of the above reasons. Very efficient loss of their fanbase.

    1. Apologies for the delay in responding (next task is to fix the email alerter to comments) Whilst I had no issues with the T12 binding up to SPI (albeit under Betaflight) there is a tuning part of the multimodule that might be useful to try if you are failing to bind at all (although I’m not clear if you need to be using LBT or not) If you look at this video https://youtu.be/IOlwe57lh4c the same logic that applies for getting the best RSSI also applies if you can’t bind at all. Try moving the frequency tune up one way, and then the other until you can find the right one to bind and then you can pin down that mid point to fine tune to

      1. Ah not a worry! Managed to get the thing working. Turns out our good friend ACCST v2 was causing all the trouble on my x9Lite. Once it was rolled back to V1, and that really useful hidden lua script installed (thank you for pointing that out), everything works, albeit in D16.

        The morning it all began working again, my T16 arrived back hahaha, so now I’m well and truly inundated with ways to bind to a mobula… Learned a lot in any case!

  3. Not sure if I am missing something here, but I am still not able to get this to work with ma X9 Lite. I have OpenTX 2.3.9 and the ISRM on my radio is running “1.1.0/1.1.3 EU”. I am trying to bind it to a BetaFPV F4 Brushed v1.1 FC running BetaFlight 4.2. I’ve tried to downgrade to 4.1 and 4.0 as well without any difference.

    Neither binding Frsky_X_LBT with the EU “mode” nor does switching to FCC on my radio thanks to your Lua script with Frsky_X on the receiver seem to work. The radio just endlessly keep on beeping while binding and that’s it.

    Is there anything I might’ve missed?

    1. SPI receivers are weird things and act quite differently from everything else I can think of – including not giving much of an indication when they’ve bound. Have you gone through the actual full bind process, that is set your radio to bind, then typing bind_rx in the cli, then take the radio out of bind and type save in the cli. If you don’t do all these steps, then the bind process isn’t complete. After the betaflight configurator restarts, have a look in the receiver tab and check if your are bound

  4. I did try that. When I power on the board its LED goes to solid green indicating it being connected or in bind mode. Since it’s clearly not connected it does still seem to be in bind mode.

    The support page indicates you have to wait up to a minute for the receiver to bind to the radio or at least to update the frsky variables. Unfortunately this did never happen. Even after several minutes. No matter if it’s running on FRSKY_X or _LBT. Neither running the bind command followed by a diff or alternatively by saving first did update the frsky_ variables.

    1. One thing to remember is when you switch between FCC and EU-LBT you need to power off then on your tx to enable the change to function.

  5. I finally got it bound! Looks like there’s something different with the BF 4.x firmware. The board comes pre-flashed with BF 3.4.1 and I thought it’d be a good idea to update it. Looks like it was a bad idea. I went back to BF 3.4.1 flashing it with BF Controller 10.2 and well, I’ve got it bound to my radio.

    My radio is in FCC mode so I’ll see if it also works with LBT as well.

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