Using The Node-Red Library

If you want to save a flow or function and reuse it later in another flow on the same computer then you can save it to the local library. To save a flow to the library highlight all nodes in the flow by using CTRL+A then use the main menu (top right) and select Export>Library.

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Understanding And Using MQTT v5 Request Response

Web Applications have a direct connection between the sender and receiver. The sender is the client (web browser) and the receiver is the server. They implement a command response message flow were the client(browser) makes a request and the server responds and there is a direct connection between client and server.

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MQTT v 5.0 New Features Overview

MQTT v5 introduced many new features and changed how some existing features work. In this tutorial I will be covering all of these features with brief examples, and also in many case, links to detailed examples and videos.

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Deploying Node-Red Flows

When you come to deploying a flow you have four (node-red v0.2)options as shown below: Although the choices appear obvious the effect of the options isn’t and can cause some confusion.

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Working with JSON Data And JavaScript Objects in Node-Red

JSON is popular format for encoding data sent over the Internet, and also stored in files. In computing, JavaScript Object Notation (JSON) is an open-standard file format that uses human-readable text to transmit data objects consisting of attribute–value pairs and array data types (or any other serializable value). –wiki

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Using the Node Red Status Node

In Node red any node can report status information in the visual editor. The screen shot below shows the mqtt node. It shows a green circle to indicate that it is connected and the text connected underneath the node.

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Control Raspberry Pi GPIO Pins Using MQTT

The Raspberry Pi has 40 General purpose Input/output Pins (GPIO) that can be used for controlling external hardware. There are  a number of add-on boards called hats which plug into these pins and provide various sensors. The most common one being the sense hat.

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