BDBD ROS2 conversion 1

Today I created a new repo bdbd2 and a new ROS2 workspace bdbd2_ws to begin converting my bdbd code to ROS2. I’m going to follow all of the lessons that I learned during work on fqdemo.

Documentation Boilerplate

First, I’ll create standard ROS2 files. I’ll have three packatges: messages, meta, and nodes. This is intended as support for the hardware on my modified Jetbot Nano-based robot.

Create the basic packages, and init the workspace:

ros2 pkg create --build-type ament_cmake --license Apache-2.0 bdbd2_msgs
ros2 pkg create --build-type ament_cmake --license Apache-2.0 bdbd2_nodes

I also created a package for bdbd2. The folder hierarchy is:

bdbd2_ws/
  src/
    bdbd2/
      package.xml
      bdbd2_msgs/
        package.xml
      bdbd2_nodes/
        package.xml

Update each package.xml with description, author, urls.

Add CHANGELOG.rst, README.md, and CONTRIBUTING.md in each package (they already have LICENSE, package.xml, and CMakeLists.txt from ros2 package create

Problems with my metadata format

colcon build is not finding my subpackages. I traced the issue: in `github/colcon/colcon-recursive-crawl/colcon_recursive_crawl/package_discovery/recursive_crawl.py’ we have this code:

                try:
                    result = identify(identification_extensions, dirpath)
                except IgnoreLocationException:
                    del dirnames[:]
                    continue
                if result:
                    descs.add(result)
                    del dirnames[:]
                    continue

If I change this to this it works:

                try:
                    result = identify(identification_extensions, dirpath)
                except IgnoreLocationException:
                    del dirnames[:]
                    continue
                if result:
                    descs.add(result)
                    # del dirnames[:]
                    continue

I can also make it work by adding an option --base-paths . ./*/* to colcon commands. So my conclusion is, this is not working. I don’t think that is a reasonable approach.

So I am going to revise fqdemo.