In order for an external computer to talk with the PixHawk 2.1, I setup a connection on Telem2 as it is shown below:
I am using a standard USB2Serial converter and the dongle has been set for 3.3V. when I connect the USB2Serial on the computer, /dev/ttyUSB0 appears, no problem.
on PX4 side, SYS_COMPANION has been set to 921600 bauds
This set up works perfectly well on the Pixracer but with the PixHawk 2.1, I get no transmission from the Pixhawk, i.e. when I launch MAVROS, it is starting and then wait for px4 but there is no response.
Can you tell me what is missing here? Thank you very much for your help