Book Image

Practical Node-RED Programming

By : Taiji Hagino
5 (1)
Book Image

Practical Node-RED Programming

5 (1)
By: Taiji Hagino

Overview of this book

Node-RED is a free and open source flow-based programming tool used to handle IoT data that allows programmers of any level to interconnect physical I/O, cloud-based systems, databases, and APIs to build web applications without code. Practical Node-RED Programming is a comprehensive introduction for anyone looking to get up to speed with the Node-RED ecosystem in no time. Complete with hands-on tutorials, projects, and self-assessment questions, this easy-to-follow guide will help you to become well versed in the foundations of Node-RED. You’ll learn how to use Node-RED to handle IoT data and build web applications without having to write complex code. Once you’ve covered the basics, you’ll explore various visual programming techniques and find out how to make sample flows as you cover web development, IoT development, and cloud service connections, and finally build useful real-world applications. By the end of this book, you’ll have learned how to use Node-RED to develop a real-world application from scratch, which can then be implemented in your business.
Table of Contents (19 chapters)
Section 1: Node-RED Basics
Section 2: Mastering Node-RED
Section 3: Practical Matters

Making a flow for a data handling application

In this section, you will create a working application (called a flow in Node-RED). Whether it is the internet of things (IoT) or server processing as a web application, the basic operation that Node-RED performs is sequentially transferring data.

Here, we'll create a flow where JSON data is generated in a pseudo manner, and the data is finally output to standard output via some nodes on Node-RED.

There are many nodes on the left-hand side of the palette. Please pay attention to the common categories here. You should be able to easily find the inject node, as shown in the following screenshot:

Figure 3.4 – Inject node

This node can inject a message into the next node. Let's get started:

  1. Drag and drop it onto the palette of Flow 1 (the default flow tab).

    You will see that the node is labeled with the word timestamp. This is because its default message payload is a timestamp value. We...