Fixed – Inverter Mod for TBS Crossfire and FrSKY QX7, X10S & X12
If you get constant telemetry warnings you might be affected. The reason is a wrong inverter on the FrSky QX7 wich can not handle the 400k baudrate of the CRSF protocol.
Your Radio Link to the aircraft is not affected, just the telemetry or LUA Script.
Solution 1: Software fix
You can set the Baudrate to 115200 and your Crossfire Module will work without any issues.
Be aware: The lower baudrate will slow down the CRSF protocol
This workaround will give you a baudrate selection on your X7 menu (main menu, hardare page). If you lower it to 115’200baud instead of using 400’000baud the issue is resolved. Due this workaround and the lower baudrate the latency will increase. The regular update rate for CRSF between OpenTX and Crossfire is 250Hz (4ms). Using the lower baudrate the update rate is reduced to 62.5Hz (16ms). Because of this we recommend to fix it properly in hardware if you have the soldering skills or ask FrSky for support on fixing the hardware.
- Download latest Taranis Firmware
- copy the firmware onto the SD Card into the „FIRMWARE“ folder
- start the Taranis in bootloader mode
- flash firmware and select 115200
- Go Fly!
Solution 2: Hardware fix
I created the following PCB wich TBS and many online shops now sell. With this mod, you can get the full 400k baudrate for your TBS Crossfire System.
You can get this Inverter via TBS or for example the german FPV Racing Online Store RCTech.de
Warning: Only do the hardware mod if you know what you are doing. To desolder SMD components you need a bit of tact. The components around it can be damaged very easily if you don’t do it correctly. Please make these modifications only on your own responsibility/risk. Neither TBS, FrSky or I can guarantee that the mod works! Thank you!
Please follow the guide below:
Mod for FrSKY Horus QX7
Mod for FrSKY Horus X10S
Thanks Yann Bouloiseau for the photos and information for this mod!
Mod für FrSKY Horus X12
Thanks to stxShadow for the Mod – Thanks to www.aircrasher.de for the photo of the PCB