- What is Node-RED?
- What programming language does Node-RED use?
- How do I install and start Node-RED?
- What is a flow in Node-RED?
- How can I store data in Node-RED?
- What is the function node, and how do I use it?
- How do I handle JSON data in Node-RED?
- How can I create a dashboard in Node-RED?
- What is the message object in Node-RED?
- How do I deploy flows in Node-RED?
- What are buffers, and how are they used in Node-RED?
- What is a Subflow
- How do I install a new Node?
- Where are newly installed nodes Installed?
- How or When Does a Flow start?
- Can I deploy more than One Instance of node-red?
- How do I secure my Node-RED instance?
- How can I back up my Node-RED flows?
- How do I share my Node-RED flows with others?
- Is it possible to use Node-RED with Python scripts?
- How do I schedule tasks in Node-RED?
- How do I set up Node-RED to start automatically on system boot?
- Can I use an existing nodejs module in my node-red flow?
- How Does node-red Handle Errors?
What is Node-RED?
Node-RED is an open-source, flow-based tool and IoT platform developed by IBM, written in Node.js. It allows users to build applications by connecting predefined functions (nodes) through a web interface, requiring minimal programming knowledge. It’s particularly suited for creating IoT and home control dashboards and automations.
What programming language does Node-RED use?
Node-RED is built on Node.js, which uses JavaScript as its programming language. Users typically write JavaScript code when configuring function nodes or extending Node-RED.
How do I install and start Node-RED?
To install Node-RED locally, follow the instructions provided in the Installing and Starting Node-RED tutorial. This guide covers installation steps for various operating systems and how to initiate the Node-RED editor.
What is a flow in Node-RED?
A flow in Node-RED is a collection of interconnected nodes that define the pathways for data to travel. Each flow appears as a tab in the workspace and represents a specific functionality or process within your application. See Node-red Flows
How can I store variable data in Node-RED?
Node-RED provides context storage options to retain data across different nodes and flows. You can use context, flow, and global variables to store data in memory or persist it to the file system for retrieval after a restart. Detailed information is available in the Storing Data in Node-RED Variables tutorial.
What is the function node, and how do I use it?
The function node allows you to execute custom JavaScript code within your flow. It receives a message object (msg) as input and can return one or more message objects as output. This node is essential for implementing custom logic and processing within your flows. A beginner’s guide is available at Using the Node-RED Function Node.
How do I handle JSON data in Node-RED?
Node-RED can process JSON data using various nodes and methods. The function node can parse JSON strings into JavaScript objects and vice versa. Additionally, the JSON node can convert between JSON strings and objects automatically. For more details, refer to Working with JSON Data and JavaScript Objects in Node-RED.
How can I create a dashboard in Node-RED?
To create dashboards in Node-RED, you need to install the dashboard nodes, which are not included in the core nodes. Once installed, these nodes enable you to design interactive user interfaces for your applications. A step-by-step guide is available at Create a Node-RED Dashboard.
What is the message object in Node-RED?
The message object (msg) is a standard JavaScript object that flows between nodes in Node-RED. It typically contains properties like payload, topic, and _msgid. Understanding the structure and usage of the message object is crucial for effective flow development. More information can be found in Understanding and Using the Node-RED Message Object.
How do I deploy flows in Node-RED?
After creating or modifying flows, you need to deploy them to apply the changes. Node-RED offers various deployment strategies, such as full, modified nodes, and modified flows, each catering to different scenarios. An in-depth explanation is provided in Deploying Node-RED Flows.
What are buffers, and how are they used in Node-RED?
Buffers in Node-RED are used to handle binary data, which is essential when dealing with protocols or devices that communicate in binary formats. They allow you to manipulate raw data efficiently. A comprehensive guide is available at Understanding and Using Buffers in Node-RED.
What is a Subflow
A subflow is a collection of connected nodes that can be used as a single unit just like a node.
It is a way of packaging functionality from several nodes.
See this tutorial and also this video
How do I install a new Node?
You can add additional nodes to your node-red dashboard using
- npm
- Node-Red editor
npm install -g package-name
Or to install for your user i.e.locally. Go to your home directory and type
npm install package-name
In the node-red editor go to menu>manage palette and click the install tab and then type the package name or type in the search box to search for a package.
The node should appear in the node list
Where are newly installed nodes Installed?
They are stored in the node_modules folder under the .node-red folder.
How or When Does a Flow start?
When triggered by an event. A common event is triggered by the inject node or an incoming message e.g MQTT.
Can I deploy more than One Instance of node-red?
Yes they will need to run using a different port. This can be done using the -p switch on the command line.
How do I secure my Node-RED instance?
To secure your Node-RED instance:
- Set up user authentication by editing the settings.js file to include admin and user credentials.
- Implement HTTPS by configuring the settings.js file with the paths to your SSL certificate and key.
- Regularly update Node-RED and its nodes to the latest versions to ensure security patches are applied.
See The Beginners Guide to the Node-Red Settings.js
How can I back up my Node-RED flows?
At a minimum to back up your flows, you can save the flows .json file, located in your .node-red directory. It’s also a good idea to back up your settings.js file if you’ve customized it.
How do I share my Node-RED flows with others?
You can export your flows as JSON files using the export feature in the Node-RED editor and share these files. The recipient can then import the JSON into their Node-RED instance. See How to Export and Import Flows-Node-Red
Is it possible to use Node-RED with Python scripts?
Yes, you can execute Python scripts from Node-RED using nodes like node-red-node-daemon or exec. These nodes allow you to run external commands, including Python scripts, and capture their output.
See Using the Exec Node to Run External Commands
How do I schedule tasks in Node-RED?
Use the Inject node with a scheduling configuration to trigger flows at specific times or intervals. You can set up tasks for daily, weekly, or custom schedules.
How do I set up Node-RED to start automatically on system boot?
For Linux systems, you can use the Node-RED service script. Run:
sudo systemctl enable nodered.service
Can I use an existing nodejs module in my node-red flow?
It often occurs that there is no existing node-red node to do a task but there is an existing nodejs module. Node-red let you use the external modules in the function node see Using external nodejs modules.
How Does node-red Handle Errors?
Node-RED handles errors by using try-catch blocks in function nodes and error-handling nodes like the Catch node. see Handling errors in node-red flows
.