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.
Continue readingMQTT and Raspberry Pi GPIO
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.
Continue readingNode-Red HTTP Request Node for Beginners
The node-red http request node is a core node and can be used for making http requests. It can be used for. Retrieving web pages from a website Making API Request Sending and receiving JSON data to a website or API. etc
Continue readingNode-Red MQTT Data and Topic Logger
This is a data and topic logger similar to the python data and topic loggers that can be used for logging MQTT data to log files either as a single file containing multiple topics or multiple files based on topic. It is controlled using a node-red dashboard making it much easier to use than the python loggers.
Continue readingSimple Python MQTT Topic Logger
The MQTT data logger logs data to all monitored topics to the same log files. If the data need to be split into topics then it will need to be done by the log analyser software.
Continue readingBeginners Guide to Data and Character Encoding
When I first starting working with computers everything was in ASCII ( American Standard Code for Information Interchange ) However today working with networking protocols and network programming you will come across a variety of data and character encoding schemes. In this tutorial we will look at basic encoding schemes used on computers and in the second part of the tutorial we look at how data is sent over a network.
Continue readingUsing the Node-Red Function Node- Beginners Guide
The function node is used to run JavaScript code against the msg object. The function node accepts a msg object as input and can return 0 or more message objects as output. This message object must have a payload property (msg.payload), and usually has other properties depending on the proceeding nodes.
Continue readingUsing MongoDB Working Notes
If you’re new to mongoDB and are looking to use it on one of your IOT projects then you might find my working notes useful. Install – Manual links to install on multiple platforms How to Install mongoDB on Windows 10. The database files are stored in c:\data\db on Windows (default) and in the folder /var/lib/mongodb on Linux (Raspberry pi).
Continue readingHow MQTT Works -Client Connections
MQTT is a messaging protocol i.e it was designed for transferring messages, and uses a publish and subscribe model. This model makes it possible to send messages to 0,1 or multiple clients.
Continue readingMQTT Publish and Subscribe Beginners Guide
In MQTT the process of sending messages is called publishing, and to receive messages an MQTT client must subscribe to an MQTT topic.
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