TBS Crossfire Setup with Betaflight

This simple guide explains how I setup TBS Crossfire with my Taranis X9D Plus in Betaflight, how to connect and configure Crossfire receiver, how to bind, how to setup LUA script, etc. The process should be similar in other Frsky radios.

Further Reading: How to choose a radio transmitter?

Table of Contents


What’s special about TBS Crossfire?

The TBS Crossfire is a popular RC system for its excellent range and lower latency. The Crossfire is an external RF module you can install directly on the back of your Taranis, so you can still use the powerful OpenTX OS and our beloved Frsky Taranis radio.

The Crossfire operates at the 900MHz band and therefore it has much better penetration ability and longer range than the typical 2.4GHz we use on racing drones. However, the downside is the larger, longer receiver antennas, as well as the more strict regulations surrounding the lower frequency.

Despite the Frsky Taranis with a full range receiver (e.g. the R-XSR) can theoretically provide 1.5Km range, which is more than enough for most of mini quad pilots. There are times we want longer range or simply more reliable signal behind obstacles, the Crossfire is a good solution for this. The other advantage of Crossfire is the lower latency which reportedly improves the handling of the quadcopter according to many well known pilots.

The available Crossfire modules and accessories are:

TBS Crossfire TX Module TBS Crossfire Micro TX Module
– Built-in screen for changing settings
– Max Power up to 2W
– Extra features: Spectrum analyzer, Bluetooth module
– No screen, settings changed via LUA script only
– Max Power up to 100mW
– Lighter, smaller, cheaper
Amazon | GetFPV GetFPV | RDQ

TX Module Antennas

Stock Antenna Diamond Antenna (Upgrade)
– Durable, Cheap
– Can be used for receiver
– More reliable performance
– Slightly directional – more range in front of the pilot than behind
– Durable design
TBS GetFPV | Amazon | TBS

Receivers

Crossfire Micro RX Crossfire Nano RX
It uses a JST header for connection Same capability as the Micro RX, but a lot smaller!
Connection is solder pads
GetFPV | TBS RDQ | GetFPV | Amazon

RX Antennas

Stock Dipole Antenna Immortal Antenna
– Cheap, simple, lightweight and flexible – Same performance but stronger, and heavier
TBS GetFPV | TBS

Check out our recent review where we compared the two popular long range systems, the Crossfire and the Frsky R9M.


Update OpenTX on Taranis

In theory, OpenTX 2.2.0 should work (release, May 2017), but some improvements were made to the Crossfire LUA script in the newer version, therefore it’s recommended to update your Taranis to OpenTX 2.2.1 (release, Jan 2018) or newer firmware.

Here is how to update OpenTX firmware on your Taranis.


Updating TBS Crossfire Firmware

Check and update your Crossfire TX module to the latest firmware, to do this, download and install the TBS Agent software: http://www.team-blacksheep.com/corepro/agent

Launch the TBS Agent software, and connect your Crossfire TX module to your computer using the Micro USB port.

If there is a newer version, click the “Update” button to update the firmware. This should only take a few minutes.

TBS Agent

TBS Agent – Updating TBS Crossfire TX Module firmware

Every time you update the firmware on your TX module, you also need to update the firmware on your RX. This can be done wirelessly using your TX module, we will cover that part in the binding process below.


Installing Crossfire TX module in the Taranis

You can install the Crossfire TX module directly in the external module bay in your Taranis. Insert the module into the module bay very carefully, make sure all the pins go into the sockets of the Crossfire module properly.

TBS Crossfire Micro Module Installed on the back of the Taranis X9D

TBS Crossfire Micro Module Installed on the back of the Taranis X9D

Beware that the Crossfire module is only fully compatible with Taranis X9D Plus. It also works with Taranis Q X7, and Horus X10, but there are some minor issues due to the inability of operating at full baud rate, causing problems such as constant warning of “telemetry lost”. There is a DIY mod you can do to fix this.


Setup Taranis to use Crossfire TX Module

Turn on your Taranis, and create a new model for your quadcopter that will be using Crossfire, or you can just use an existing model if you already have one.

Short press the Menu button to enter the Model Setup page, scroll down to “Internal RF” and set mode to “OFF“.

Next set the mode under “External RF” to “CRSF” and change “Channel Range” to “CH1-16“.

Once you’ve done this and exit this menu, the Crossfire TX module should power up (LED lights up on the back).


Connection – TBS Crossfire Receiver and Flight Controller

Remember that almost all of the pins on the Crossfire receiver can be mapped in software. This means there are many different ways of connecting the RX to the flight controller. I will show you how I connect mine and map the pins, you can follow exactly what I do here.

Connection is simple, 5V to 5V, GND to GND, CH1 (Crossfire) to UART RX, CH2 (Crossfire) to UART TX. You can use any spare UART on the flight controller, but they have to be the same numbered UART.

You can also just connect CH1 and set it up to output SBUS, but I want to use CRSF protocol so you will need to connect both wires.

Note that the CRSF protocol is NOT an inverted protocol like SBUS or SmartPort, therefore you must not use dedicated SBUS or SmartPort pin on an F4 FC which has built-in signal inverter for that pin. However this doesn’t matter on F3 and F7 FC’s as the inversion can be switched on or off in software.

You cannot use Soft Serial either, because they are not fast enough for the data connection.

In this example, I am connecting the Crossfire RX to the UART 6 of the Kakute F4 AIO V2 FC.

Crossfire Micro Receiver:

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Crossfire Nano Receiver:

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Binding Crossfire TX module and RX

Pairing the Crossfire TX Module and the RX for the first time can be very confusing. It’s easier with the full version TX module because you can read the instructions on the LCD screen.

TBS Crossfire "Full" Module Installed on the back of the Horus X10

TBS Crossfire “Full” Module Installed on the back of the Horus X10

With the Micro version you have to guess what’s going on with the status LED which is not very intuitive. Therefore I prefer to use the LUA script to pair my TX and RX. This script comes with OpenTX 2.2, so you DON’T need to download anything extra :)

Here are the steps to bind the Crossfire TX module with the RX:

  • Power on the RX, it should be flashing red
  • Short press the bind button on the RX, it should be flashing green now, which indicates it’s waiting for the bind signal from the TX
  • Turn on your Taranis
  • Long press the Menu button on the Taranis to enter the Radio Setup page. Press “page” once to enter the “SD Card” page
  • Select the “CROSSFIRE” folder and long press “crossfire.lua”, select “execute” from the dropdown list

  • In the next screen, select the only option, “XF Micro TX”
  • In the new screen (as shown below), select the second option “Binding”

  • You will be prompted the message “Binding…”, and a few seconds later, you will be prompted to confirm if you want to update the receiver, and you should press “Enter”
  • It will take a few minutes to update the RX’s firmware, once it’s done, the lights on both the RX and TX should stay green
  • The pairing is complete

Configure RX from Taranis

Once your TX module and RX are paired, you should be able to configure your RX from your Taranis using the LUA script.

Long press the Menu button on the Taranis to enter the Radio Setup page. Press “page” once to enter the “SD Card” page.

Select the “CROSSFIRE” folder and long press “crossfire.lua”, select “execute” from the dropdown list.

You can now configure both the TBS Crossfire TX and RX. If you don’t see the option “XF Micro/Nano RX”, it means your receiver is either not bound or the power is off.

The first thing you want to do is configure your receiver output mapping to get it to talk to Betaflight.

To do this, press into “XF Micro/Nano RX”, scroll down to “Output Map”, and change “Output 1” to “CRSF TX”, “Output 2” to “CRSF RX”. That’s it :)

Take a look at the rest of the settings and change whatever you need, the most important thing is to make sure you are using the legal frequency and transmission power for your region – US should be using 915MHz while Europe should be using 868MHz.


Configure Betaflight for Crossfire

The last step is to setup Betaflight to recognize the Crossfire protocol.

Go to the “Ports” tab in the Betaflight configurator, and enable “Serial RX” in the UART you’ve connected to the TBS Crossfire receiver. Press “Save”.

Now go to the “Configuration” tab, under the “Receiver” Section, select “Serial-based receiver“, and select “CRSF” in the second option.

Don’t forget to enable “Telemetry” feature too before pressing “Save”.

Finally, go to the “Receiver” tab, you should now see response from stick movement. This means your receiver is working! If the channels are in the wrong order, just choose a different “Channel Map”.

If you are not getting any response at all, go back and check your wiring, Output Map setting for the receiver, and Betaflight configurations.

That’s it, you have successfully setup Crossfire in Betaflight :)

To make sure Telemetry is working correctly, go to the Telemetry page in the Taranis, and select the option “Discover new sensors”, it should begin to pick up data from the flight controller including VFAS (battery voltage).


Mounting the Crossfire Receiver Antenna

If you have been using other radio systems, the first problem you are going to run into is mounting the unusually large receiver antenna. Here are some examples of the most popular antenna types including the stock dipole antenna and the Immortal T antenna.

Image credit: Eric Konasty

Image credit: beeb

To maximize range and signal strength, try to avoid getting the antenna blocked by the frame. Do not bend the antenna and keep them in the angle they are designed to. Replacement antennas are often out of stock, therefore you should keep them away from spinning props.

There are a million ways to mount the Crossfire antennas, it hugely depends on your mini quad frame. Don’t forget to search for 3D-printed antenna holders available on Thingiverse.


Setup LUA Script to Change PID & Betaflight Settings

You can install a LUA script that allows you to change many Betaflight settings on your quad, including PID, rates, looptime, filters parameters, as well as your VTX channels and power level!

The setup process is very similar to using SmartPort, except your don’t need to change any settings in Betaflight because it’s all done in this tutorial (i.e. Telemetry). You only need to following the instructions to download the LUA script and set it up in the Taranis, and you are good to go!

Setup LQ and RSSI on OSD and Taranis Warning

This tutorial explains what LQ and RSSI are in Crossfire, and how to display it on your OSD and setup warning in the Taranis.

FAQ

Here we will address some of the popular questions.

How many people can fly on Crossfire?

Aoccrding to TBS, theoretically, 50 people, but tt’s been tested when there are 12 people, the radio link quality becomes noticably worse but still flyable, so they don’t recommend any higher number of pilots than that using Crossfire at the same time :)

Thank you, HobbyRC.co.uk

A huge shout-out to HobbyRC for providing me the Crossfire Nano radio receiver for this tutorial, make sure to check out their website: https://www.hobbyrc.co.uk.

15 thoughts on “TBS Crossfire Setup with Betaflight

  1. Jimmy Thompson

    I am getting ready to attempt to setup crossfire on my Emax Hawk 5 with the Magnum F4 AIO. I cannot find out which pins have UART on them. Has anyone else attempted this? If so which TX and RX pads have uarts on them?

    Reply
  2. Arnaud De Smedt

    Hi there,
    Any idea where it is best to connect my GPS to ? Got RX TX SCL and SDA, best connecting them to Crossfire NANO or to my flight controller ?

    Reply
    1. Hadyan

      Just connect to Flight Controller, make sure you have enough UART port to provide maximum feature of the GPS

      My 6″ and 7″ Long Range setup uses Omnibus F4 v2/Pro Flight Controller, I choose this because it have enough UART port and with GPS enabled, you have feature like Magnetometer, Barometer, Compass…

      Reply
    2. cubitusclaudius

      I have the same problem and I will try to connect it to the crossfire nano. At least SDA and SCL. I made the mistake to buy an Omnibus AIO F7 V2 from Airbot and you only have 3 full UART : UART1 UART3 and UART6
      UART2 and UART7 have only RX which means they are absolutely useless.
      I need to connect :
      – Tramp Telemetry (on a TX)
      – Crossfire on an UART (TX and RX)
      – GPS (another complete UART)
      – Compass (I2c which means SCL/SDA)

      If I don’t connect compass to the Nano, i’ll have to skip Tramp telemetry which is a pain for a long range frame. The problem is I don’t even know if it does work? there is very poor literature on the subject, and even Oscar Liang that I admire skips the subject of SCL/SDA pads on the Nano

      Reply
  3. Graham

    Hi, I’ve interested in getting crossfire but was wondering whether it would work with Turnigy 9XR PRO? Does it work with any OpenTX transmitter?

    Reply
  4. jazep

    Hi! Thanks for very good instrucfion!
    I am interested, can I install the crossfire mini in my flysky 9X transmitter?
    Thank You very much!

    Reply
  5. Haybeseret

    Hi,
    As usual, very informative.
    Only thing i can comment on is that TBS as well as Trappy on interviews indicate that you should monitor LQ and not RSSI. (I.E send LQ on one of the receiver channels and preset it on the OSD).
    On top in the Taranis the recommend configuring alerts base on calculation of RFMD and LQ (using special function, and logical switches)

    Reply
  6. Markus

    Hey Oscar,

    showing the RSSI-value on my OSD doesn’t work, when I set CH8 to RSSI. But it’s working, if I set CH8 to “LQ”…do you know what the problem could be?

    Reply
    1. Oscar Post author

      Yes I think i might have made a mistake about using RSSI as RSSI… LQ is the right one but there are extra steps to convert the value or something, i need to dig into that and update the guide.

      Reply
  7. JonathanD

    Can you change vtx through lua this way?

    I wired channel 4 to smart audio channel(tx 1)
    Then in crossfire tx changed ch.4 to smart audio.
    If i don’t have to do these extra steps then that me great.

    Thank you!

    Reply

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