ROS2 Tutorials #8: How to communicate between ROS1 & ROS2 with ros1_bridge
In this post, you will learn how to communicate between ROS1 & ROS2 with ros1_bridge. You will see how to set up the ros1_bridge package in order to send ROS2 commands to control a TurtleBot2 simulation running in ROS1 Melodic.
Step 1: Grab a copy of the Project (ROSject) on ROSDS
Click here to get your copy of the project used in this post.
Step 2: Launch the TurtleBot2 simulation from the Simulations menu
Now you should see a Simulation window pop up with the TurtleBot2 simulation.
Step 2: Source the workspace for ROS1 Melodic
Pick a Shell (terminal tool) from the Tools menu and run the following command:
user:~$ source /opt/ros/melodic/setup.bash user:~$
Step 3: Source the workspace for ROS2 Dashing
In the same Shell used in Step 2, run the following command:
user:~$ source /opt/ros/dashing/local_setup.bash ROS_DISTRO was set to 'melodic' before. Please make sure that theenvironment does not mix paths from different distributions. user:~$
Step 3: Ensure ROS_MASTER_URI is pointing in the right direction:
Still on the same shell, run the following:
user:~$ echo $ROS_MASTER_URI http://master:11311 user:~$ export ROS_MASTER_URI=http://master:11311 user:~$
Step 4: Communicate between ROS1 & ROS2 with ros1_bridge: start the ros_bridge
Now, start the ros1_bridge and put this terminal on one side – we’re done with it for now.
user:~$ ros2 run ros1_bridge dynamic_bridge Created 2 to 1 bridge for service /gazebo/clear_body_wrenches Created 2 to 1 bridge for service /gazebo/clear_joint_forces Created 2 to 1 bridge for service /gazebo/delete_light Created 2 to 1 bridge for service /gazebo/delete_model Created 2 to 1 bridge for service /gazebo/get_joint_properties Created 2 to 1 bridge for service /gazebo/get_light_properties Created 2 to 1 bridge for service /gazebo/get_link_properties ...
Step 5: Control the ROS1 TurtleBot2 Simulation from ROS2
Fire up another Shell from the Tools menu and publish to /cmd_vel.
user:~$ source /opt/ros/dashing/local_setup.bash ROS_DISTRO was set to 'melodic' before. Please make sure that the environment does not mix paths from different distributions. user:~$ ros2 topic pub /cmd_vel geometry_msgs/Twist "linear: x: 0.5 y: 0.0 z: 0.0 angular: x: 0.0 y: 0.0 z: 0.0" publisher: beginning loop publishing #1: geometry_msgs.msg.Twist(linear=geometry_msgs.msg.Vector3(x=0.5, y=0.0, z=0.0), angular=geometry_msgs.msg.Vector3(x=0.0, y=0.0, z=0.0))
In the shell where you’re running the ros1_bridge, you should see messages similar to the following:
created 1to2 bridge for topic '/rosout' with ROS 1 type 'rosgraph_msgs/Log' and ROS 2 type 'rcl_interfaces/msg/Log' created 2to1 bridge for topic '/cmd_vel' with ROS 2 type 'geometry_msgs/msg/Twist' and ROS 1 type '' created 2to1 bridge for topic '/rosout' with ROS 2 type 'rcl_interfaces/msg/Log' and ROS 1 type 'rosgraph_msgs/Log' [INFO] [ros_bridge]: Passing message from ROS 2 geometry_msgs/msg/Twist to ROS 1 geometry_msgs/Twist (showing msg only once per type)
And, of course, you should see that your robot started to move!
And that was it 😉 . We just controlled a simulation started in ROS1 with ROS2, using the ros1_bridge.
Extra: Video
Prefer to watch a video demonstrating the steps above? We have one for you below! PS: the video uses another simulation, a Parrot Drone, but the concepts are the same.
Related Resources
Feedback
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If you want to learn about other ROS or ROS2 topics, please let us know in the comments area and we will do a video or post about it 🙂
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Post edited by Bayode Aderinola
#ROS2 #ROS #ROS2tutorials #Robot