@chart-sg/node-red-ros2

A Node-RED package providing ROS2 integration with seamless multi-plugin compatibility through the Chart SharedManager architecture.

⚠️ IMPORTANT: Terminal Installation Required

Cannot be installed via Node-RED Palette Manager. This package requires terminal installation with ROS2 environment sourced because rclnodejs needs access to ROS2 libraries during installation.

Key Improvements

• Manager Integration: Built-in @chart-sg/node-red-ros2-manager for seamless multi-plugin compatibility
• Async Initialization: Robust async patterns with proper error handling
• Hot Redeployment: Proper cleanup and re-initialization support
• Multi-Plugin Compatible: Works alongside @chart-sg/node-red-rmf and other Chart ROS2 plugins
• ActionClient Reliability: No spinning conflicts or nullptr errors

Installation

# 1. Source ROS2 environment
source /opt/ros/jazzy/setup.bash        # (or your ROS2 distro)

# 2. Install in Node-RED directory
cd ~/.node-red
npm install rclnodejs
npm install @chart-sg/node-red-ros2

The @chart-sg/node-red-ros2-manager dependency is automatically installed.

Architecture

This package uses the Chart SharedManager architecture:

┌─────────────────────────────────────────────────────────────┐
│                @chart-sg/node-red-ros2-manager              │
│              (Shared ROS2 Context Manager)                 │
└─────────────────────┬───────────────────────────────────────┘
                      │
          ┌───────────┴──────────┐
          │                      │
┌─────────▼──────────┐  ┌────────▼─────────┐
│ @chart-sg/node-    │  │ @chart-sg/node-  │
│ red-ros2           │  │ red-rmf          │
└────────────────────┘  └──────────────────┘

Benefits:

• No ROS2 context conflicts between plugins
• Shared spinning coordination - efficient resource usage
• ActionClient reliability - no spinning conflicts or nullptr errors
• Automatic lifecycle management - proper cleanup during redeployments

Usage

All nodes automatically use the SharedManager for reliable ROS2 operations:

// Nodes automatically use SharedManager (always available)
const manager = require('@chart-sg/node-red-ros2-manager');
await manager.initialize();
const {node, nodeId} = await manager.createNode('my_node');

Compatibility

• SharedManager Integration: Guaranteed multi-plugin compatibility with shared ROS2 context
• Node-RED: Hot deployment, proper cleanup, lifecycle management
• Multi-Plugin: Works seamlessly with @chart-sg/node-red-rmf and other Chart ROS2 plugins

Available Nodes

• Publisher - Publish ROS2 messages
• Subscriber - Subscribe to ROS2 topics
• Service Client - Call ROS2 services
• Action Client - Execute ROS2 actions
• ROS2 Types - Message type definitions
• DDS Settings - Configure DDS parameters

🔗 Related Packages

• @chart-sg/node-red-ros2-manager - Shared ROS2 context manager
• @chart-sg/node-red-rmf - RMF integration for Node-RED

Node-RED palette

The main concepts associated with Node-RED operation are explained here. The plugin nodes are displayed on the Node-RED palette as shown in the image. From there, they can be dragged into the flow workspace.

These palette represents the basic ROS client features like publishing and subscribing to a ROS topic, requesting an ROS service or performing a ROS action. With this features it should be possible to control existing ROS system like a robot and to use higher level application like the Nav2 (Navigation Stack).

Note : the text that labels the node, changes from palette to workspace, and may change depending on the node configuration.

Publishing and Subscribing to an ROS Topic

In order the publish or subscribe data we need first to specify the associated type. The topic type is represented by the node ROS2 Type. It is required that the ROS2 Type is connected to the Publisher or Subscriber Node.

Choosing a ROS2 type

Injecting a type instance into the pipeline

Node-RED pipelines start in source nodes. The most popular one is the inject node which requires the user to manually defined each field associated to the type. In order to simplify this a specific node is introduced:

This node mimics the inject node behaviour but automatically populates the input dialog with the fields associated with any type node linked to it. For example, if we wire together a ROS2 Inject and a ROS2 Type as shown in the figure:

The associated dialogs are populated with the linked type fields and types. For example the twist message is populated as:

ROS2 nodes: General Settings

In order to interact with a ROS2 environment we must specify the same domain id in use for that environment.

The domain id is a number in the range [0, 166] that provides isolation for ROS2 nodes. It defaults to 0 and its main advantage is reduce the incomming traffic for each ROS2 node, discharging them and speeding things up.

Another key concepts in the ROS2 environment are:

• topic one. A topic is a text string ROS2 nodes use to notify all other nodes in which data they are interested. When a ROS2 node wants to send or receive data it must specify:

• Which type is the data they want receive. For example the edu_robot/RobotStatusReport we introduced above.
• Topic associated with the data. For example /status_report, but in ROS2 topics are often decorated using namespaces to simplify identification, as in /eduard/red/status_report.

• Quality of Service (QoS). Those are policies that allow fine tunning of the communication between nodes. For example:
  • History QoS allows to discard messages if only the most recent one is meaningful for our purposes.
  • Reliable QoS enforces message reception by resending it until the receiver acknowledges it.
  • Durability QoS assures messages published before the receiver node creation would be delivered.

Note: ROS2 nodes can only communicate if their respective QoS are compatible. Information on QoS compatibility is available here.

ROS2 Subscriber

Example

This example shows how to subscribe to an topic and display it using the debug node. It is based on the available topics of an EduArt's robot like Eduard.

ROS2 Publisher

Example

This example shows how to publish to an topic and display the published message using the debug node. It is based on the available topics of an EduArt's robot like Eduard.

ROS2 Service Client

In order to call or request an ROS service we need first to specify the associated type. The service type is represented by the node ROS2 Service Type. It is required that the ROS2 Service Type is connected to the Service Client node.

Example

This example shows how to call a service and displays the response using a debug node. It is based on the available topics of an EduArt's robot like Eduard. In this example the robot is switched in mode autonomous drive.

ROS2 Action Client

In order to perform a ROS action we need first to specify the associated type. The action type is represented by the node ROS2 Action Type. It is required that the ROS2 Action Type is connected to the Action Client node.

Original Project

This fork is based on edu-nodered-ros2-plugin by EduArt Robotik.

📄 License

ISC License - see LICENSE file for details.