Publish binary time data when use_sim_time parameter is true

[achim-k]

Public-Facing Changes

• Publish binary time data when use_sim_time is true

Description
Depends on foxglove/ws-protocol#299

• When the use_sim_time parameter is set

  • The server advertises the time capability
  • It subscribes to the /clock topic and broadcasts binary time messages

• I have removed the code that detects presence of the /clock topic, since now it has to be known at startup whether use_sim_time is true or false

• Includes Make server capabilities configurable #115 (will rebase after it got merged)

[jhurliman]

For ROS 1 we retrieve /use_sim_time. I'm not familiar enough with ROS 2 params to know if this is correct or if we should be using the / prefix here.

[achim-k]

In ROS 2 the use_sim_time is not global anymore but every node declares that paramter (automatically). From what I read, the main challenge is setting this parameter for all nodes when e.g. launching multiple nodes in a launch file

[tonynajjar]

From what I read, the main challenge is setting this parameter for all nodes when e.g. launching multiple nodes in a launch file

I happened to see this comment by mistake and want to share a tip; You can set the use_sim_time for all your Nodes inside a GroupAction in this way:

from launch.actions import GroupAction
from launch_ros.actions import SetParameter

GroupAction(
        actions=[
            SetParameter("use_sim_time", True),
            Node(...),
            Node(...)
       ]
)