I have a FC Skystars F405 HD2 connected with a ESP32 (Arduino) by a serial link (100kbauds, parity even, 2 stop bits, inverted).
25 bytes are sent, starting with byte 0x0F and ending with byte 0x00.
The flight controler seems to catch the frame but does not decode it correctly. I spied the serial transmitter using Saleae Logic 16. I attached the capture of the first bytes sent. The first parameter sent is the throttle position (1498=101 1101 1010).

According to Futaba S-bus protocol, the LSBit shall be transmitted first. So, that's why the throttle is not equal to 1498 but equal to 733 (010 1101 1101).
I've added the inversion in my ESP32 software because the sbus library doesnot do it. Can you confirm that the library does not and I have to do it in my software ?
And, finally, if you have any idea why the flight controller shows me the value 1338 for the throttle (observed in Betflight) instead of 1498, it would help me.
Thanks.