Brewing with Node-RED pt 1: Introduction

Node-RED is a popular framework for visual programming. It is included with Raspbian, the official operating system of Raspberry Pi, and sees wide use for interfacing IoT devices and task automation. Programming in Node-RED is flow orientated – essentially signals or messages propagate through nodes which each deliver some functionality (e.g. directing, modifying, or expanding a message)

These flows are created using a visual editor, and 1000s of user created and maintained nodes exist to do pretty much anything with a simple drag, drop, and route workflow. If the included and contributed nodes are not enough, and you have some basic programming experience, it is easy to write your own function nodes using JavaScript. You can even call code written in some other language if you wanted. Pretty damn flexible.

The messages themselves may be invoked through interaction from a user (e.g. a button click on an associated dashboard), some scheduled regular injection, various input nodes, etc. For example, you can have a node which streams messages from a DS18B20 temperature sensor. You may route that message to a node that provides some kind of smoothing functionality, then to to a UI element that displays the current temperature.

Example flows in which a temperature reading is triggered by regular insertation of a timestamp. This temperature reading is smoothed for display in UI, and it is also routed to a PID algorithm.

While a dashboard is not necessary for a Node-RED project, they are commonly used. Lots of basic UI widgets are included with Node-RED-dashboard, the default dashboard package. These should cover most of what you would want to use, but again, you can also write your own widgets. Elements from Angular Material can be used without any extra setup or configuration, and this makes it relatively easy to create fully customized, modern and attractive widgets. You are not restricted to using Node-RED-dashboard however, and can use essentially any other front end library (e.g. vue.js) that you may want to build your dashboard if you want further flexibility. Check out the short video below for a demo of a custom ui widget I made – the lightning bolts indicate power and ability to power each of my two brewery elements (I prevent powering of both elements simultaneously with my Node-RED dashboard)

From CraftBeerPi to Node-RED

It’s easy to see why Node-RED is so popular across the complete range of programming experience levels and applications. About 18 months ago I think it was, I began playing with Node-RED myself. The programming style was a bit different from what I was used to, but eventually I became somewhat proficient in it and built a dashboard to control my homebrewery.

In comparison to CraftBeerPi, which is probably the most popular software on the Raspberry Pi for brewery control right now, a Node-RED dashboard is certainly more “assembly required”. It does have the benefits of wider use even if that use is not homebrewing specific though. The Node-RED discourse forum has thousands of questions and posts from other hobbyists and makers on how to do specific things with Node-RED, which can be easily related back to homebrewing. In comparison to the CraftBeerPi project, development is much more active, the project is much more stable, and it is also truly opensource (Apache 2.0 license).

For a user wanting custom functionality, endless control, and not afraid to get their hands dirty, Node-RED a good match.

Continue reading Brewing With Node-RED pt 2 here.

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