Creating and building ROS2 in Drone
===================================

If there is a problem with the action or the topic in the drone, you need to delete and create the action and topic again. Remove all the content of the ``Drone`` folder except the ``src`` folder and the ``Logs`` folder.

Create a workspace
------------------
.. code-block:: bash

   cd Drone
   mkdir src
   cd src

State Vector Publisher
----------------------

Create a package
~~~~~~~~~~~~~~~~
In ``Drone/src``, execute:

.. code-block:: bash

   ros2 pkg create --build-type ament_python --license Apache-2.0 state_vector_pubsub

Import the publisher node
~~~~~~~~~~~~~~~~~~~~~~~~~
Navigate into ``Drone/src/state_vector_pubsub/state_vector_pubsub``. Then, move into the directory the ``.py`` modules that are in ``src/state_vector_pubsub/state_vector_pubsub``.

Add dependencies
~~~~~~~~~~~~~~~~
Add the following dependencies into ``package.xml`` (``Drone/src/state_vector_pubsub``):

.. code-block:: xml

   <exec_depend>rclpy</exec_depend>
   <exec_depend>std_msgs</exec_depend>

Add an entry point
~~~~~~~~~~~~~~~~~~
In ``setup.py``, add the following line within the ``console_scripts`` brackets of the ``entry_points`` field:

.. code-block:: python

   entry_points={
           'console_scripts': [
                   'talker = py_pubsub.publisher_member_function:main',
           ],
   }

Check ``setup.cfg``
~~~~~~~~~~~~~~~~~~~
Check that ``setup.cfg`` has the following content:

.. code-block:: ini

   [develop]
   script_dir=$base/lib/state_vector_pubsub
   [install]
   install_scripts=$base/lib/state_vector_pubsub

Build and run
~~~~~~~~~~~~~
Still in the root of your workspace, ``Drone``, build your new package:

.. code-block:: bash

   colcon build --packages-select state_vector_pubsub

Open a new terminal, navigate to ``Drone``, and source the setup files:

.. code-block:: bash

   source install/setup.bash

Now run the talker node:

.. code-block:: bash

   ros2 run state_vector_pubsub talker

Action Server
-------------

Create an interface package
~~~~~~~~~~~~~~~~~~~~~~~~~~~
In ``Drone/src``, execute:

.. code-block:: bash

   ros2 pkg create --license Apache-2.0 commands_action_interface

Restore the action
~~~~~~~~~~~~~~~~~~
Create an ``action`` directory in the ROS 2 package ``commands_action_interface``:

.. code-block:: bash

   cd commands_action_interface
   mkdir action

Move ``Commands.action`` from ``src/commands_action_interface/action`` into ``Drone/src/commands_action_interface/action``.

Building the action
~~~~~~~~~~~~~~~~~~~
Add the following lines to ``CMakeLists.txt`` before the ``ament_package()`` line:

.. code-block:: cmake

   find_package(rosidl_default_generators REQUIRED)

   rosidl_generate_interfaces(${PROJECT_NAME}
     "action/Commands.action"
   )

Add the required dependencies to ``package.xml``:

.. code-block:: xml

   <buildtool_depend>rosidl_default_generators</buildtool_depend>
   <member_of_group>rosidl_interface_packages</member_of_group>

Build the package by executing the following commands:

.. code-block:: bash

   # Change to the root of the workspace
   cd ~/Drone
   # Build
   colcon build

Run the server
~~~~~~~~~~~~~~
Move all the ``.py`` modules from ``src/commands_action_interface/src`` to ``Drone/src/commands_action_interface/src``.

To run the server, open a new terminal, navigate to ``Drone``, and source the setup files:

.. code-block:: bash

   source install/setup.bash

Now run the server:

.. code-block:: bash

   python3 src.commands_action_interface.src.commands_action_server.py