Public MQTT Brokers and Reserved Topics – Discussion Post

Preface This is a discussion post and these are currently my thoughts on this topic. I would be grateful for comments and feedback. Introduction MQTT is still in the early stages of deployment and currently is used only on private networks. However with the growth in the adoption of the MQTT protocol for information distribution the number of public brokers and topics will probably increase substantially just as happened with websites in the early days of the internet.

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Configuring the MQTT Publish and Subscribe Nodes in Node-Red

Node-Red provides both an MQTT subscribe (input) and publish (output) node. The configuration for these nodes are almost Identical as the main part of the configuration concerns the actual client connection. Because of this it is useful to think of the publish and subscribe nodes as consisting of two components as shown in the schematic below: Before we look a the actual configuration we will look at MQTT client connections in general.

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Logging MQTT Sensor Data -Notes

Data from sensors will need to be stored. But how much data do you really need to store? Many sensors like state sensors (ON/OFF), temperature etc will fluctuate very little over the course of a day so does it makes sense to store the same sensor value every x seconds?

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Creating an MQTT Broker With CloudMQTT

Cloud based brokers are likely to become very popular in the future for organisations they operate over a wide geographic area. In addition they provide a nice user interface making it very easy to setup your own broker instance and you don’t need to have to manage your own virtual server. CloudMQTT like Amazon,Azure etc provide a managed cloud based mosquitto broker. The plans on CloudMQTT are shared plans which means that several MQTT brokers run on the same hardware.

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MQTT Keep Alive Interval Explained With Examples

MQTT uses a TCP/IP connection. This connection is normally left open by the client so that is can send and receive data at any time. If no data flows over an open connection for a certain time period then the client will generate a PINGREQ and expect to receive a PINGRESP from the broker.

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Creating an IOT or MQTT Dashboard Using Thingsboard

Thingsboard is an open source IOT platform for data visualization. It is available for download and installation on your own hardware or as an online service for demonstration purposes. In this tutorial we will configure a simple Dashboard to display data from sensors using MQTT and Python.

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