.. brash_groundsystem_demo:


BRASH Groundsystem BRIDGE Demo
##############################

This page will take you through how to run a BRASH bridge that communicates with the cFS ``TO_Lab`` and ``CI_Lab`` applications. 

It uses a number of ROS2 `messages <https://github.com/traclabs/cfe_ros2_bridge_plugin/src/devel/cfe_msgs/msg/>`_ that have been automatically generated from cFS binaries, each with a dedicated topic.  

This example provides a demonstration on how a ROS2 ecosystem running as part of a mission Ground System could communicate with a flight-side cFS instance.  

The basic architecture of this bridge looks like:

   .. figure:: _static/brash_gs_bridge_arch.png
      :width: 500px
      :alt: BRASH Groundsystem Bridge
      :align: center

Start cFS
=========

.. code-block:: bash
    
    $ cd ~/code/cFS/build/exe/cpu1
    $ ./core-cpu1 2>&1 | tee out.txt


Start the BRASH groundsystem bridge
===================================

.. code-block:: bash
    
    $ cd ~/code/brash
    $ . install/local_setup.bash
    $ ros2 launch cfe_plugin cfe_bridge.launch.py


Use rQT to enable TO messages 
===============================

#. In a new terminal start the ``rQT`` UI. 

   .. code-block:: bash

      $ ros2 launch brash_application_tools groundsystem_demo.launch.py


#. Enable TO output by using the **Message Publisher** plugin to send a command message to the ``/groundsystem/to_lab_enable_output_cmd`` topic. 

   .. figure:: _static/enable_to.png
      :width: 800px
      :alt: Enable TO output
      :align: center

   * You will need to expand the ``payload`` field in the UI and set the ``dest_ip`` the approprate IP, probably ``'127.0.0.1'`` unless you have changed it in ``TO_Lab`` and ``CI_Lab``.
   * Send the command by right clicking over the message in the **Message Publisher** window and selecting **Publish Selected Once**. 

   .. warning::
   
      The step above is fundamental to get the data flowing to the ground!  You'll see in the terminal running :code:`./core-cpu1` a line showing that the request was received:
               
      .. figure:: _static/cfs_terminal_after_to_lab_enable_highlighted.png
         :width: 600px
         :alt: core-cpu1 message showing TO Lab message received
         :align: center 


#. Check and expand the cFE ES Housekeeeping Telemetry topic ``/groundsystem/cfe_es_hk_tlm`` in the **Topic Monitor** window.  You should now see telemetry data coming from cFS and translated into a ROS2 message.

.. figure:: _static/view_to.png
   :width: 800px
   :alt: View TO output
   :align: center