The AWS DeepRacer control ROS package creates the ctrl_node, which is part of the core AWS DeepRacer application and launches from the deepracer_launcher. More details about the application and the components can be found in the aws-deepracer-launcher repository.

This is a main node with services exposed to be used by webserver backend API calls. This node manages the device's different modes [manual, autonomous, calibration]. It allows us to maintain the device in a single mode at any point of time so that the overlapping functionalities (such as servo messages) do not conflict with each other. Also, this can be extended to add more modes, as in the Follow the Leader (FTL) sample project.

The source code is released under Apache 2.0 (https://aws.amazon.com/apache-2-0/).

Follow these steps to install the AWS DeepRacer control ROS package.

The AWS DeepRacer device comes with all the prerequisite packages and libraries installed to run the ctrl_pkg. For more information about the preinstalled set of packages and libraries on the AWS DeepRacer, and about installing the required build systems, see Getting started with AWS DeepRacer OpenSource.

The ctrl_pkg specifically depends on the following ROS 2 packages as build and run dependencies:

1. deepracer_interfaces_pkg: This package contains the custom message and service-type definitions used across the AWS DeepRacer core application.
2. camera_pkg: The AWS DeepRacer camera ROS package creates the camera_node, which is part of the core AWS DeepRacer application.
3. servo_pkg: The AWS DeepRacer servo ROS package creates the servo_node, which is part of the core AWS DeepRacer application.
4. inference_pkg: The AWS DeepRacer inference ROS package creates the inference_node, which is part of the core AWS DeepRacer application.
5. model_optimizer_pkg: The AWS DeepRacer model optimizer ROS package creates the model_optimizer_node, which is part of the core AWS DeepRacer application.
6. deepracer_navigation_pkg: The AWS DeepRacer navigation ROS package creates the deepracer_navigation_node, which is part of the core AWS DeepRacer application.

Open a terminal on the AWS DeepRacer device and run the following commands as the root user.

1. Switch to the root user before you source the ROS 2 installation:

    sudo su
   

2. Source the ROS 2 Foxy setup bash script:

    source /opt/ros/foxy/setup.bash 
   

3. Set the environment variables required to run Intel OpenVino scripts:

    source /opt/intel/openvino_2021/bin/setupvars.sh
   

4. Create a workspace directory for the package:

    mkdir -p ~/deepracer_ws
    cd ~/deepracer_ws
   

5. Clone the ctrl_pkg on the AWS DeepRacer device:

    git clone https://github.com/aws-deepracer/aws-deepracer-ctrl-pkg.git
   

6. Fetch unreleased dependencies:

    cd ~/deepracer_ws/aws-deepracer-ctrl-pkg
    rosws update
   

7. Resolve the ctrl_pkg dependencies:

    cd ~/deepracer_ws/aws-deepracer-ctrl-pkg && apt-get update
    rosdep install -i --from-path . --rosdistro foxy -y
   

8. Build the ctrl_pkg, camera_pkg, servo_pkg, inference_pkg, model_optimizer_pkg, deepracer_navigation_pkg, and deepracer_interfaces_pkg:

    cd ~/deepracer_ws/aws-deepracer-ctrl-pkg && colcon build --packages-select ctrl_pkg camera_pkg servo_pkg inference_pkg model_optimizer_pkg deepracer_navigation_pkg deepracer_interfaces_pkg
   

The ctrl_node provides basic system-level functionality for the AWS DeepRacer application to work. Although the node is built to work with the AWS DeepRacer application, it can be run independently for development, testing, and debugging purposes.

To launch the built ctrl_node as the root user on the AWS DeepRacer device, open another terminal on the AWS DeepRacer device and run the following commands as the root user:

1. Switch to the root user before you source the ROS 2 installation:

    sudo su
   

2. Source the ROS 2 Foxy setup bash script:

    source /opt/ros/foxy/setup.bash 
   

3. Source the setup script for the installed packages:

    source ~/deepracer_ws/aws-deepracer-ctrl-pkg/install/setup.bash  
   

4. Launch the ctrl_node using the launch script:

    ros2 launch ctrl_pkg ctrl_pkg_launch.py
   

The ctrl_node provides the core functionality to manage the device's different modes of operation. The ctrl_pkg_launch.py is also included in this package. It provides an example demonstrating how to launch the nodes independently from the core application.

    from launch import LaunchDescription
    from launch_ros.actions import Node

    def generate_launch_description():
        return LaunchDescription([
            Node(
                package='ctrl_pkg',
                namespace='ctrl_pkg',
                executable='ctrl_node',
                name='ctrl_node'
            )
        ])

• Getting started with AWS DeepRacer OpenSource