The current hardware revision of FrSky X7 and X10S is not fully compatible with the TBS CROSSFIRE CRSF protocol. The symptoms are a constant telemetry warning. Currently there are two solutions to fix this. One is a software based workaround and second one is a hardware fix for the FrSky X7 and X10S.
This workaround will give you a baudrate selection on your X7 and X10S 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.
- Update your TBS CROSSFIRE to V2.07 or newer
- Update your FrSky X7 to 2.2.1 or newer (OpenTX)
WARNING: AS THE FRSKY X7 IS NOT A TBS PRODUCT THIS IS ON YOUR OWN RISK AND MAY VOID YOUR WARRANTY!!
This will fix the issue without loosing performance due lower CRSF speed and doesn't require any firmware update.
Instructions and parts can be found here:
TARANIS QX7 MOD