Node-RED: Lecture 6 – Example 6.7 Multiple inputs on a function node

Example 6.7 Multiple inputs on a function node

Function nodes in Node-RED were designed to process messages as single entities. However, in some cases your functions might depend on two separate data sources. There are many ways to handle these cases in Node RED. The following approach uses the context object in Node-RED and topics to let a function wait for several messages to arrive in order to return.… Read the rest

Node-RED: Lecture 6 – Example 6.3 Using context to generate rolling averages

Example 6.3 Using context to generate rolling averages

A special module called context, used to store data between function invocations, is available to function nodes. This can be useful when the function needs to retain state to do its processing. For example, in a typical Industrial IoT scenario, it may be necessary to compute the average value of a sensor’s data readings over a period of time.… Read the rest

Node-RED: Lecture 8 Advanced flows with Node-RED


This lecture is a set of links to advanced tutorials we have written. These include:

  • Tutorial: Using FRED (Cloud Node-RED) to build an AI chatbot using IBM Watson
  • Tutorial: Using FRED (Cloud Node-RED) with the GE Predix Timeseries Microservice
  • Tutorial: Using OPC-UA with FRED (Cloud Node-RED)
  • Monitor a Pi Zero hosted security camera with Node-RED & MQTT
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Smart City standards: an overview

Making sense of Smart City standardization activities

Update: For a fuller discussion of Smart City technologies, including standards, read Smart City Technology Trends

Last year I was asked to write an article on Smart City standards for the IEEE standards magazine. This blog post was the basis for that article, but also acts as an evolving document as I update it as standards activities evolve.… Read the rest

Tutorial: Node-RED dashboards – creating your own UI widget II (using external charts)

Creating your own UI widget for a Node-RED dashboard using an external charting library

Node-RED’s dashboard nodes provide a comprehensive set of UI components for building basic dashboards suitable for the Internet of Things (IoT) – offering graphs, gauges, basic text as well as sliders and inputs. However, there will always be situations when you need something custom.… Read the rest