Publish JSON Data over MQTT with Node-Red

One of the the most common use scenarios for using JSON data is for combining data from multiple sources.
In this tutorial we will simulate a multi-sensor environment were we collect data from several sensors and publish it wusing MQTT on a single topic using JSON encoded Data.
The video also demonstrates how we can hold and delay publishing data while we combine it.
To accomplish this we use a fuction node and use the context object to store sensor values before we publish them.
Related Tutorials and Resources
Flow used in video
stevesnoderedguide.com/downlo...
-
stevesnoderedguide.com/workin...
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Introduction to JSON
www.w3schools.com/js/js_json_...
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Working With JSON Data in Node Red
• Working With JSON Data...
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Creating a Simple Controllable MQTT Sensor With Node-Red
• Creating a Simple Cont...
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The Node-Red Message Object for Beginners
• The Node-Red Message O...
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Create a Node Red Basic Flow - MQTT Subscribe Example
• Quick Introduction to ...
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How to Create a Node-Red MQTT Dashboard
• How to Create a Node-R...
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How to Store Data In Node Red Variables
• How to Store Data In N...
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Receive JSON Data Over MQTT with Node-Red
• Receive JSON Data Over...
Have a question Use the comments or if you want help then use
www.steves-internet-guide.com/...
If you find these videos useful then you might want to consider buying me a coffee
www.paypal.me/StepenCope

[@loggerman247]

Hi Steve, just wanted to say how clear and understandable your tutorials are; you have helped a great deal! Cheers, Adrian

[@astrogerard]

Thanks for sharing and taking the time to make these useful tutorials.

[@zhinadr534]

You really helped me a lot, I watched almost all of your videos. Thank you.

[@stevecope]

Glad to be of help
rgds
steve

[@nurwardiahspian9833]

thanks for sharing..this is a very useful tutorials

[@anamariadragulinescu8088]

The only node you have not opened (for the settings) was JSON....

[@petersamoaa8535]

Hi, Thanks for your useful video
but just I need to ask you about thing.
suppose that I have Mosca broker on my local machine and send JSON data related to GPS position with the format
{ payload: __, context: { lat: __ lng: __ }, timestamp: __ }
and other Mqtt subscribe in this content.
can you illustrate this ?!

[@stevecope]

Peter
Do you mean how to decode it?

[@petersamoaa8535]

Steve Cope yes that's exactly what i mean

[@stevecope]

Hi
I've just uploaded a video that explains it. I hope!
ruclips.net/video/jeSg4bM8Kf0/видео.html

[@petersamoaa8535]

Thanks so much I'm going to see it