Line by line ROS2 commands needed to Launch node, build, etc.

1. source src/docker_humble_jetson/attach.sh
   a) If you are doing a clean build on a new docker you need to do this first otherwise the custom msg won't build. If you see an error message, it's normal and you can ignore it.
   b) for clean build do: rm -rf build/ install/ log/
   c) NEVER build in the src/ folder. The docker automatically goes into src/ so don't forget to do a cd .. to go back one.

2. colcon build --packages-select custom_msg
   a) build custom msg first

3. colcon build
   a) build the project

4. source src/docker_humble_jetson/attach.sh
   a) Source again for ROS. Not neceassrily needed but sometimes it is and just good practice to avoid debugging for no reason

5. ros2 launch avionics_nexus launch.py
   a) launch avionics pipeline. Also launches the python node.
   b) This is a specific command for the current code. General syntax is: ros2 launch node_name launch_file

6. docker exec -it elec_humble_desktop bash
   a) If you want multiple terminals, allows you to attach them to the same docker.

7. ros2 topic pub /EL/servo_req custom_msg/msg/ServoRequest "{id: 1, increment: 50.0, zero_in: false}"
   a) simulate publisher message from CS to see if your system works b) can add a --once and a bunch of other things if you want, just google them.

8. ros2 topic echo /EL/mass_topic
   a) allows you to see what the message received by the RP from the avionics

9. ros2 topic list
   a) show all ros2 topics