Converting JSON to CSV with Python

JSON formatted data is a common way of sending data over MQTT. Storing the data directly as JSON formatted data is also common However it is also very common to store this data as CSV or a least convert it to CSV for use in legacy systems.

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How to Use the Python MQTT Client with a Backup Broker

Introduction In this project we will be developing python scripts to use a backup broker to publish and receive messages to improve message reliability in failure situations. MQTT offers three QOS settings -0,1,2 as described in the understanding QOS tutorial. QOS levels 1 and 2 require an acknowledgement from the MQTT broker and provide for reliable message transfer. However there are many circumstances were just relying on these QOS levels isn’t sufficient.

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Receiving Messages with The Paho node.js MQTT client

Messages are received by processing the message event.The format is: function (topic, message, packet) {} Example code is shown below: //handle incoming messages client.on(‘message’,function(topic, message, packet){ console.log(“message is “+ message); console.log(“topic is “+ topic); console.log(“packet =” +JSON.stringify(packet)); console.log(“packet retain =” +packet.retain); });

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Using MQTT Explorer

MQTT explorer is a free cross platform MQTT client that is very useful for MQTT testing. You can download the client here. The client lets you subscribe to topics and publish messages to topics using a graphical interface. In addition is shows retained messages and allows you to easily delete them.

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Filter MQTT Topics -Python Utility Function Example

One of the most common tasks when handling MQTT messages is topic filtering. Generally you will be subscribing to a topic base using a wild card e.g sensors/# so you will receive all messages published with the topic base of sensors. So you will receive messages on topics like:

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Controlling Devices Using MQTT and Python-Part 2

Welcome back to the workshop/project. If you haven’t read part one then it is here- Continue to part 1 We can send commands to our device and change the name we will now. Implement support for the backup name Get the device to report status data

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Configure Mosquitto to use a Commercial Certificate for SSL

There are three main ways of obtaining SSL certificates but purchasing a commercial certificate from a provider is probably the most popular option. When you do this you will be provided with a collection of files. In this tutorial we look at using the certificates provided by Thawte to configure a mosquitto broker to use SSL. We will be configuring the broker to support MQTT+SSL and also MQTT+websockets +SSL

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