Hi,
I wanted to thanks the one who wrote the 9bit hardwareserial. It saved me an headache.
For people waiting to write their own xpressnet throttle with an arduino, i used the hardwareserial class with a mega 2560 : if people are interested i put it on github: GitHub - nzin/xpressnet_arduino: A Xpressnet protocol implementation for Arduino Mega 2560
With a basic schema:
And for people speaking french, there is my first basic implementation
I hope it can help and serve others.
The alone thing that i'm not happy with is the flush method after writing data on the serial link. It is not working as i was expecting, so i used delay() before telling the rs485 to switch back to listening state