Hello adis1313 and thank you for your time and effort.
If you could build a library that make us complile for the stm32 bluepill for arduino, it would be great! The mega is limited and big in size. My quadcopter use Joop brokkings famous code and the stm32 bluepill is cheap, fast and reliable 
So it would be a benefit send ibus data to my TX on ground (as a safety, I know where my drone is regardless of other systems onboard).