In this guide we're gonna walk through TBS crossfire setup with Micro Tx, along with Crossfire Nano receiver and Taranis X9D. Similar steps can be used with various OpenTX radios. Crossfire should allow you to reach much longer distances than using regular receiver like R-XSR, stability of the radio link is pretty impressive.
What is TBS Crossfire?
TBS Crossfire is currently the most reliable long-range FPV radio link.
It is an external module that can be installed in the JR bay of your radio controller.
This long-range system isn’t only used by long-range pilots but also by those who always want to have a stable connection and those who do not want to worry about getting failsafes in risky locations.
What frequency is crossfire?
Crossfire operates at the 900MHz band and the lower frequency, compared to 2.4Ghz that is used in almost all stock radios, has better penetration through objects and is more stable.
TBS Crossfire Range
MAX RANGE @10mW: 20km
It's tough to say precisely how much a long-range module will enable your system to proceed. There are a lot of variables that can both increase and decrease range. Antenna quality, antenna positioning on the drone, damaged or improperly installed antennas, atmospheric interference, and so forth.
Nevertheless, it's safe to say that you could get at least two miles of perfect range. The important thing is to examine your system in a secure place and have a failsafe plan like having a self-powered beeper and GPS rescue setup.
Flying a long-range is obviously risky and you have to be prepared if you lose the signal, danger of losing a drone is large. Locating it can be extremely tough. We do not recommend long-range flying for beginners. When you start transitioning to fly long-range you want to ensure you have the equipment you can rely on.
Is TBS Crossfire Legal?
Legal to use everywhere across the world, pending permission by the federal RF management organizations. This implies you don't require to have a HAM license to run it, and you can use crossfire system lawfully when doing a paid work. It's also legal to use in any EU country because of the compliance with the harmonized SRD standard.
TBS Crossfire comes in a few different warriants:
Crossfire Micro Tx vs The Full Version
TBS Crossfire Micro TX V2
TBS Crossfire TX Module Full
The full size TX Module is capable of delivering up to 2W, it has a built-in screen for changing settings and has some extra features like the spectrum analyzer, etc. The full size TX needs to be powered by an external Lipo because of it’s high power so that is also one thing to consider while choosing between the two.
For standard Freestyle and Race flying, Micro TX module is more than capable of delivering enough power. Having no screen isn’t a big deal because once the settings are set, there is no need to change them except changing the output power.
Micro TX supports power up to 250 mW and a range of around 10 km. All of freestyle and race flying is usually no more than 1 km or so in which case the Micro TX is more than enough. It is a nice compact unit weighing only 48g that fits neatly in the JR bay with no bulky unit stuck to the back of the transmitter compared to the 76g and large footprint of the full size Crossfire unit.
A few things that may bother you except the power limit on Micro TX is that it has no bluetooth connections for feeding the telemetry data to a phone app, it doesn’t have an OLED screen for quick navigation and changing the settings nor the spectrum analyser. All of those things sound very useful but in real life we didn’t find ourselves using them at all.
There are a few different receivers made for TBS Crossfire. The most used ones are the Nano and Diversity Nano RX.
Crossfire Nano RX
Nano RX is a perfect receiver for FPV mini quads because it is small, light and easy to set-up.
Crossfire Diversity Nano RX
The Diversity receiver can be also used in mini quads but its real purpose is for long-range models in which situations diversity may help avoiding lost connections.
There are 2 types of Crossfire Antennas, the transmitter antenna and receiver antenna.
Crossfire TX Antennas
TBS crossfire modules come with their stock TX antenna which is good enough for your standard flying and doesn’t need upgrading at all, but there are also other options like the Diamond TX antenna which is a slightly directional antenna that provides better penetration through objects and is more durable.
Crossfire RX Antennas
TBS Crossfire receivers come with either their stock or Immortal-T antenna which is our way to go. Some people may like the stock antenna more because it can be mounted to a quad in other ways to make it more durable.
How to setup TBS Crossfire
For a first time setup, you will need your module, a Crossfire receiver, and antennas along with some wires that come with the receiver.
Crossfire Module Setup
Put the antenna on the module and install it into your radios JR bay. Make sure to never power it on without an antenna because that might blow it up.
Creating Crossfire Model
Once you’ve installed your module into your radio, it is time to create a new model, specially dedicated to Crossfire. The cool thing with it is that once you’ve bound with one receiver, they will connect automatically even if you bind more receivers to the module later.
That’s the reason we are creating one separate model for Crossfire and not a single receiver or a single quad... You will be able to use this model with all of your quadcopters that are equipped with Crossfire.
Crossfire Firmware Update
After you’ve done the radio set up, connect your module to the TBS Agent X application on your PC or MAC and check for updates. One of the best features of Crossfire is that the module automatically detects if the firmware on the receiver is outdated and if it is, it simply asks you if you want to update and it does it all by itself, over the air.
For the receiver, you will need 4 wires. If you can, use the same wire colors as we do so you don’t get lost later. The wires that you see in the picture come with the receiver in the box and are high quality and so we recommend you use them.
If you want to make good solder joints, it’s important to pre-tin the pads before you solder them. Take your iron, clean it, put it on the pad and wait a bit until the pad heats up. Then, apply the solder, not to the tip of the iron but directly to the pad. If the pad is hot enough, it will take the solder with no problem.
You want your pads with solder to look round and shiny. It is very important to solder it right because if one wire gets disconnected mid-flight, your quad will failsafe and there is a possibility you’ll never see it again so take your time with these steps.
Wires came pre-tinned but we added some extra solder to them also just to make them neater.
When you’ve prepared everything, it is time to solder the wires on the pads.
The square pad with the antenna connector on the top is the ground, the one on the left of it is the 5V and two remaining pads are for the signal.
In our case, we wired the white wire to Ch. Out 1 and yellow wire to Ch. Out 2. If you wired your receiver the same as we did then the white wire should connect to the RX pad on your flight controller and the yellow wire to the TX pad.
Once you’ve soldered the wires to your receiver, connect the antenna to it, and at this point, you can cover it all with heat shrink so it’s more protected. Make sure to leave a hole for the bind button. You can cut the hole, carefully, with an X-Acto knife after you shrunk the heat shrink.
Connecting rx to flight controller
And finally, we came to the last step. Connecting it all to the flight controller.
Now you need to find an empty UART. UART is a set of RX and TX pads. Make sure that the UART that you are going to use is not already being used by something. In our case, the free UART is UART 6, so the pads are RX6 and TX6…
If you wired your receiver same as we did, the connections should be made like this:
-Black wire (ground) connects to GND pad on the FC
-Red wire (5V) connects to 5V pad on the FC
-The white wire (Ch. Out 1) connects to RX pad on the FC
-The yellow wire (Ch. Out 2) connects to TX pad on the FC
Congratulations! You’ve successfully wired up your Crossfire receiver! The only thing left is to set it up in your configuration of choice. We will show you a quick example in Betaflight.
Configure Betaflight for Crossfire
Betaflight Ports Tab
As you can see in the Ports tab, we are using UART6, check the Serial RX for the UART you are using.
Betaflight Configuration Tab
Next, in the configuration tab, you have to select your receiver mode and that is the Serial-based receiver, under that, there is the option to change the provider and set it to CRSF, then save and reboot, and after that your receiver should be working with Betaflight.
Bind the Crossfire TX module and RX
When you have a new Crossfire receiver that hasn’t been bound yet, it will automatically enter the binding mode by itself when you power it up. The only thing you need to do is press the Crossfire logo on your TX module and it will go to binding mode as well.
Once bound, the Crossfire will ask you if you want to update the RX if needed. Select accept and you are done. The only thing you need to do now is to set up your channels and you can go fly!
If your receiver isn’t binding, power it on and click the bind button once and it will enter the binding mode.
Setting up RSSI and LQ on Betaflight
When you enter LUA scripts for TBS Crossfire, you can choose between the TX and RX. In the RX menu there are a lot of options but the main thing you want to focus on is setting up an RSSI or LQ channel.
Scroll down until you reach channel map settings and choose a channel you want to use as an RSSI or LQ indicator. Simply click enter on the chosen channel and scroll up and down until you get RSSI or LQ.
In Betaflight, in the configuration tab, disable the analog RSSI input.
Go to the receiver tab and plug a battery to your quad if the receiver isn’t powered by the USB, then, turn on your radio and take a look at the lister channels. The RSSI or LQ signal should be coming from one of the AUX channels, in our case, channel 8 is AUX 4.
Once you have found your AUX channel, simply go to the RSSI Channel menu and select your AUX.
In the OSD tab, enable RSSI value and put it somewhere on the screen and you are done!
TBS Crossfire is currently the most reliable long-range and close-range radio system. The Micro TX is more than enough for FPV unless you want to go further than 10km and you really want to have that screen on the back.
Over the air receiver updates are incredible compared to Frsky’s confusing LBT and FCC firmwares that need to match. With crossfire the only thing you need to worry about is losing video and for a price of around 100 USD for the Micro TX and one receiver, it definitely pays off.
Author: Bruno Džambić Nađ
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