uXRCE-DDS Client: Expose custom participant and localhost-only flags

[DanMesh]

Solved Problem

The uxrce_dds_client can be started with flags to enable using a custom participant (-c) or localhost-only on the agent side (-l), but these were only available when starting the client by hand in the console.

Solution

Remove the CLI flags and instead a parameter for selecting the participant configuration, UXRCE_DDS_PTCFG.

This allows for selecting either the custom participant or localhost-only configuration, or neither (the default).

To Do

• Update docs: https://github.com/PX4/PX4-user_guide/blob/main/en/middleware/uxrce_dds.md

Additionally

• Improve other parameter descriptions for the uxrce_dds_client.
• Improve formatting of uxrce_dds_client status. For example:

INFO  [uxrce_dds_client] Running, connected
INFO  [uxrce_dds_client] Using transport:    udp
INFO  [uxrce_dds_client] Agent IP:           192.168.0.5
INFO  [uxrce_dds_client] Agent port:         8888
INFO  [uxrce_dds_client] Custom participant: no
INFO  [uxrce_dds_client] Localhost only:     yes
INFO  [uxrce_dds_client] Payload tx:         47811 B/s
INFO  [uxrce_dds_client] Payload rx:         0 B/s

Changelog Entry

For release notes:

uXRCE-DDS Client: expose custom participant and localhost-only flags as parameters
New parameters: UXRCE_DDS_PTCFG

Test coverage

• Tested on n FMU v5x. Enabled the parameter in various combinations to verify the behaviour.

[dagar]

Having these as both command line arguments and parameters seems like more trouble than it's worth, but otherwise looks good.

[bkueng]

At this point you could remove the CLI flags and make the param tri-state.

Can you also set it as default for v5x and v6x skynode?
In this file: https://github.com/PX4/PX4-Autopilot/blob/main/boards/px4/fmu-v5x/init/rc.board_defaults
Skynode detection: https://github.com/PX4/PX4-Autopilot/blob/main/boards/px4/fmu-v5x/init/rc.board_sensors#L52

[beniaminopozzan]

On the other hand, as the CLI is already there, what about using the same approach of the mavlink module?

PX4-Autopilot/src/modules/mavlink/module.yaml

Lines 5 to 35 in be56f74

	- command: |
	if [ $SERIAL_DEV != ethernet ]; then
	set MAV_ARGS "-d ${SERIAL_DEV} -b p:${BAUD_PARAM} -m p:MAV_${i}_MODE -r p:MAV_${i}_RATE"
	else
	set MAV_ARGS "-u p:MAV_${i}_UDP_PRT -o p:MAV_${i}_REMOTE_PRT -m p:MAV_${i}_MODE -r p:MAV_${i}_RATE"
	if param compare MAV_${i}_BROADCAST 1
	then
	set MAV_ARGS "${MAV_ARGS} -p"
	fi
	if param compare MAV_${i}_BROADCAST 2
	then
	set MAV_ARGS "${MAV_ARGS} -c"
	fi
	fi
	if param compare MAV_${i}_FORWARD 1
	then
	set MAV_ARGS "${MAV_ARGS} -f"
	fi
	if param compare MAV_${i}_RADIO_CTL 1
	then
	set MAV_ARGS "${MAV_ARGS} -s"
	fi
	if param compare MAV_${i}_FLOW_CTRL 0
	then
	set MAV_ARGS "${MAV_ARGS} -Z"
	fi
	if param compare MAV_${i}_FLOW_CTRL 1
	then
	set MAV_ARGS "${MAV_ARGS} -z"
	fi
	mavlink start ${MAV_ARGS} -x

I mean, tri state param, and the CLI flags are set in the command part of UXRCE_DDS_CFG

@bkueng , do you want v5x and v6x skynode to use -l or -c?

[DanMesh]

@beniaminopozzan Keeping the CLI and using it in the command section as you suggest is a nice idea. That way one can still stop and start the client from the console for testing, which is faster than always changing parameters and restarting.

For the defaults, I think we'd keep it that neither -l nor -c is used, as it is now.

[DanMesh]

On further thought, having both the CLI flags and a parameter for these configurations seems somewhat unnecessary.
It means there could be two "sources of truth" for what the user intends to use, and could make the setup unpredictable for someone not familiar with the way we choose between the CLI and params.

So: I have now removed the CLI flags and only have the single tri-state "participant configuration" parameter, UXRCE_DDS_PTCFG.

[bkueng]

Looks good, can you still add the skynode defaults?