Hello,
Is there a way to use PyMavLink from the RaspberryPI that is attached to the navigator and not a companion computer. When using the example code for ardusub, which tries to udpout at port 9000, no connection can be made. I’m trying to run a python script that connects to the navigator from the pi attached to it using pymavlink.
Thanks,
Paul
Hi @plwin07, welcome to the forum 
Companion had a MAVLink server endpoint at port 9000 that was shared between various Pymavlink connections. BlueOS uses mavlink-routerd instead of mavproxy, and that automatically filters out messages from any systems other than the first one to connect to a given endpoint → accordingly each endpoint can now only connect to a single system.
To work around that you can either
9000 should be usable if you want)14001) and ensure your Pymavlink script’s mavlink_connection is using the same system id (source_system) as the existing connection(s)
source_component to work, but if not it’s in principle better to use a different component id for each program within a given system