https://www.instructables.com/Turnigy-9X-Ultimate-Upgrade-FrSky-XJT-X8R-Modules-/
Turnigy 9X Ultimate Upgrade ! FrSky XJT & X8R Modules [Installation and Betaflight Configuration] :...
https://www.instructables.com/I2C-interface-to-the-FlySkyTurnigy-9x/
SPI Interface to the FlySky/Turnigy 9x : 9 Steps - Instructables
SPI Interface to the FlySky/Turnigy 9x: Interfacing a RC radio to a microcontroller is a bit of a pain, especially if you want a lot of channels, because you...
spi interfaceto theflyskyturnigy9x