ROS2 RTK setup - replacement for gcs_bridge

[diablo1281]

Issue details

Hi, I am trying to connect RTK node to mavros node.
I have a device on the network that sends Mavlink messages with RTCM for all UAVs in the network (it is seen as a vehicle with its own ID).
On ROS1 I used gcs_bridge and it worked fine. Now as I updated to ROS2 I can't get it to work. I tried to modify mavros_node to accept additional GCS in the router setup, but messages are not visible in the Mavlink Inspector on QGCS and the drone doesn't receive any RTCM messages.

I would appreciate any help on this topic.

MAVROS version and platform

Mavros: ros2 branch
ROS: Humble (compiled from source)
Ubuntu: Debian Bullseye RT

Autopilot type and version

[ ] ArduPilot
[ X] PX4

Version: 1.13.1

[vooon]

You don't need gcs_bridge anymore. Just call router to add additional link: https://github.com/mavlink/mavros/blob/ros2/mavros_msgs/srv/EndpointAdd.srv

Note that router doesn't pass messages from the same endpoint type. So message coming from GCS will be routed to FCU, but not to other GCS (i.e. QGC).

[vooon]

See also:

mavros/mavros/include/mavros/mavros_router.hpp

Lines 116 to 133 in e0be266

	/**
	* Router class implements MAVROS Router node
	*
	* Router is essential part that connects several MAVLink devices together.
	* In general there are three device classes that router uses:
	* - a FCU endpoint - should be faced to autopilot firmware(s),
	* - a GCS endpoint - that ep connects control software
	* - a UAS endpoint - special type of endpoint that is used to connect MAVROS UAS node(s) to FCU(s)
	*
	* Some traffic rules:
	* 1. FCU broadcast -> GCS, UAS, but not to any other FCU
	* 2. FCU targeted system/component -> GCS/UAS endpoint that have matching address
	* 3. FCU targeted system -> same as for p.2
	* 4. GCS broadcast -> FCU, UAS
	* 5. GCS targeted -> FCU/UAS maching addr
	* 6. UAS broadcast -> FCU, GCS
	* 7. UAS targeted -> FCU/GCS
	*/

[diablo1281]

@vooon thanks for anwers.

I still didn't get it to work. After trying to create an endpoint for the RTK station there are no incoming messages to MAVROS from it.
I did try it through C++ module code and service. Also, I disabled the block for exchanging messages between the same type of endpoint to find out it using QGC. As a result, in Mavlink Inspector I can see UAV and QGC messages, but no RTK.
Also, I did try to connect 2 QGC with different IDs and there is some strange behavior - sometimes it connects, sometimes not. Messages are getting laggy also.

I think I tried everything but without luck. Do you have any tips?

[vooon]

That's odd. Probably you can try to put mavlink-router in front of mavros router as a workaround.