AWS DeepRacer status LED package

Overview

The AWS DeepRacer status LED ROS package creates the status_led_node, which is part of the core AWS DeepRacer application and launches from the deepracer_launcher. For more information about the application and the components, see the aws-deepracer-launcher repository.

This node contains the logic for the blink and solid light effects for the status LED lights on the side of the AWS DeepRacer device. It provides services and functions that enable or disable the RGB GPIO ports for the LED lights and start and stop the particular effects on the LED lights.

License

The source code is released under Apache 2.0.

Installation

Follow these steps to install the AWS DeepRacer status LED package.

Prerequisites

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

The status_led_pkg specifically depends on the following ROS 2 packages as build and run dependencies.

• deepracer_interfaces_pkg: This packages contains the custom message and service type definitions used across the AWS DeepRacer core application.

Downloading and building

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. Create a workspace directory for the package:

    mkdir -p ~/deepracer_ws
    cd ~/deepracer_ws
   

4. Clone the status_led_pkg on the AWS DeepRacer device:

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

5. Fetch unreleased dependencies:

    cd ~/deepracer_ws/aws-deepracer-status-led-pkg
    rosws update
   

6. Resolve the status_led_pkg dependencies:

    cd ~/deepracer_ws/aws-deepracer-status-led-pkg && rosdep install -i --from-path . --rosdistro foxy -y
   

7. Build the status_led_pkg and deepracer_interfaces_pkg:

    cd ~/deepracer_ws/aws-deepracer-status-led-pkg && colcon build --packages-select status_led_pkg deepracer_interfaces_pkg
   

Usage

Although the status_led_node is built to work with the AWS DeepRacer application, you can run it independently for development, testing, and debugging purposes.

Run the node

To launch the built status_led_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-status-led-pkg/install/setup.bash 
   

4. Launch the status_led_node using the launch script:

    ros2 launch status_led_pkg status_led_pkg_launch.py
   

Launch files

The status_led_pkg_launch.py, included in this package, provides an example demonstrating how to launch the status_led_node.

from launch import LaunchDescription
from launch_ros.actions import Node

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

Services

Service name	Service type	Description
led_solid	SetStatusLedSolidSrv	A service that is called to stop the current effect on the LED light passed as a parameter and set a solid light effect with the color passed as a parameter.
led_blink	SetStatusLedBlinkSrv	A service that is called to stop the current effect on the LED light passed as a parameter and start a blink light effect with the colors passed as a parameter.

Resources

• Getting started with AWS DeepRacer OpenSource