unification_ros2_messages

A ROS2 package providing ROS2 message types and mapping rules for bridging ROS1 and ROS2 messages for the unification project. Steps to add you own message types and succesfully bridge:

Launch all the bridges

ros2 launch unification_ros2_messages unification_bridges.launch.py

Setup

Define a message type in your ROS1 package (named for example: unification_roscontrol) and save it in the msg folder of the package. Name the message, for example messageX.msg.

Edit the CMakeLists.txt file of the ROS1 package:

Uncomment the following section and add your message:

add_message_files(
	FILES
	messageX.msg
)

Uncomment line 5 in the catkin_pakcage section:

catkin_package(
	#  INCLUDE_DIRS include
	#  LIBRARIES unification_roscontrol
	#  CATKIN_DEPENDS other_catkin_pkg
	#  DEPENDS system_lib
		CATKIN_DEPENDS message_runtime
)

Uncomment the generate_messages section:

generate_messages(
	DEPENDENCIES
	std_msgs  # Or other packages containing msgs
)

Edit the package.xml file so that you have the following lines uncommented:

<build_depend>message_generation</build_depend>
<exec_depend>message_runtime</exec_depend>
<buildtool_depend>catkin</buildtool_depend>

Source your ROS1 environment file, cd into your workspace and catkin_make.
Define a message type in the unification_ros2_messages package (prefferably the same message type with the same name as in step 1) and save it in the msg folder of the unification_ros2_messages package.
Define a mapping rule in a messageX_mpr.yaml file between those two messages and save it in the unification_ros2_messages package folder. The mapping rule file should have the following format (NOTE: two spaces define one indentation):

-
  ros1_package_name: 'ros1_pkg_name'
  ros1_message_name: 'ros1_msg_name'
  ros2_package_name: 'ros2_pkg_name'
  ros2_message_name: 'ros2_msg_name'
    fields_1_to_2:
    ros1_msg_field_1: 'ros2_msg_field_1'
    ros1_msg_field_2: 'ros2_msg_field_2'
    ros1_msg_field_3: 'ros2_msg_field_3'

Edit the CMakeLists.txt file of the ROS2 unification_ros2_messages package:

Add your message type in the section:

rosidl_generate_interfaces(unification_ros2_messages
	"msg/message1.msg"
	"msg/message2.msg"
	"msg/messageX.msg"
	DEPENDENCIES builtin_interfaces
)

After the BUILD_TESTING section, add the installation rule for the messageX_mpr.yaml file:

install(
	FILES messageX_mpr.yaml
	DESTINATION share/${PROJECT_NAME})

Edit the package.xml so that in the export section you add the mapping rule:

<export>
  <ros1_bridge mapping_rules="messageX_mpr.yaml/">
  <build_type>ament_cmake</build_type>
</export>

You can use the ros1_bridge's dynamic_bridge, but for a setup where you have nonconsistent publishing and subscribing, it is more robust to have one persistent static bridge per topic. To do this, cd intro the ros1_bridge's src folder and make a copy of the static_bridge.cpp and rename it as you like, for example: sb_topic_x.cpp. Open and edit:

// ROS 1 node
  ros::init(argc, argv, "ros1_sb_topic_x");
  ros::NodeHandle ros1_node;

  // ROS 2 node
  rclcpp::init(argc, argv);
  auto ros2_node = rclcpp::Node::make_shared("ros2_sb_topic_x");

  // bridge one example topic
  std::string topic_name = "unification_roscontrol/topic_x";
  std::string ros1_type_name = "unification_roscontrol/messageX";
  std::string ros2_type_name = "unification_ros2_messages/messageX";
  size_t queue_size = 10;

Open the CMakeLists.txt of the ros1_bridge package and edit it so that you add executable generation of the .cpp you have made in the previos step like:

custom_executable(sb_topic_x
  "src/sb_topic_x.cpp"
  ROS1_DEPENDENCIES
  TARGET_DEPENDENCIES ${ros2_message_packages})
target_link_libraries(sb_topic_x
  ${PROJECT_NAME})

Delete the /build/ros1_bridge and the /install/ros1_bridge folders(not exactly sure why this is needed, but the ros1_bridge's factory generator gets confused if the bridge is not built clean. Otherwise it will also compile, but some remains of the previous build can cause problems).
In a fresh terminal, source your only your ROS2 environment, cd into the ROS2 workspace and build the workspace without the ros1_bridge with:

colcon build --symlink-install --packages-skip ros1_bridge

In another fresh terminal, source your ROS1 environment and then in the same terminal source the ROS2 environment. Now cd into your ROS2 workspace and build only the ros1_bridge with:

colcon build --symlink-install --packages-select ros1_bridge --cmake-force-configure

All done. You should be able to have your bridge up and running when you: i. Open a terminal and source the ROS1 environment ii. Then, source the ROS2 environment iii. ros2 run ros1_bridge sb_topic_x

m-dahl/unification_ros2_messages

unification_ros2_messages

Launch all the bridges

Setup