Just to get your interest – this video shows what Butler-MQTT can be used for. All the pieces are included in the Github repo. The concept of a reload dashboard can be very useful if you have long running (hours!) reloads. Instead of relying on Sense’s own reload log window, you can get an easy to understand visual feedback from a reload dashboard.
The video shows
A reloading Sense app (upper left). The app has two nested loops (date and country), with half a second delay in each.
Within each loop a status message is sent to Butler-MQTT (bottom left), which forwards the message to a MQTT server running on localhost.
A Node-RED dashboard picks up the MQTT messages and render a dashboard showing the progress of the running reload.
The “Sales” line chart deserves some comment too.
In the outer loop in the app’s load script, the script calculates sum(sales) for that particular loop iteration. That value is then sent to a MQTT topic, and then plotted in the dashboard.
This way you can get an immediate, visual feedback on the actual data produced by the reload. Not by any means always needed – but it can also be very, very useful.
For some time I have been thinking about how to improve the Sense development process as a whole. There is a lot of gathered experience and best practices from the wider software development community, but how can we apply this to Qlik Sense development?
I think more can be done though.
Looking at the concepts promoted in DevOps, it struck me that Sense development follows about the same phases as those in DevOps. Combining Sense and DevOps of course gives us….
The more I looked at it, the more I felt “wow – SenseOps really rocks!”
Continuing from the previous post about publishing data from Telldus Live to MQTT, here is small piece of related Node-RED code. It outputs a list of all (wirelessly controlled) 220V/mains switches I have linked to Telldus Live, using a Tellstick Net.
The background of the code was simply that I wanted a convenient way of getting a complete list of all devices (switches, dimmers, door bells, …) known to my Telldus Live account. When testing different devices, moving them around, renaming them etc, it is very easy to loose track of which device does what, and what their respective IDs are. This little function solves that quite nicely.
Telldus has a set of nice little gadgets (“Tellstick”, for short) that both allow you to control remote switches over radio (433.92 MHz), and to read sensors transmitting on that same frequency. Telldus also has a backend service, Telldus Live, which offer Tellstick users scheduling features (turning lamps on/off at certain times, or when certain conditions occur), as well as showing the latest sensor readings.
The above is at least true if you have a Tellstick Net, which connects to your home network and sends device and sensor data to the Telldus Live service. You can also achieve the same thing with the non-connected Tellstick models, and an always-on computer running Telldus’ software.
Anyway – let’s assume that Telldus Live can see your switches, sensors and other connected devices. Would it not be cool if you could bring all that data into Node-RED, and from there create whatever feature you dreamt of.
How about sending an SMS when the garage door is still open, but your presence data indicate that you have left for work? Easy.
Or the opposite: Send a tweet to your Node-RED server, which will then fire off an event to Telldus Live, turning a switch on, and by doing so closing the garage door? No problem.
Node-RED flow for controlling a Blink(1) USB indicator light
Node-RED is a truly awesome framework for visually building data flows. There is a lot of focus on wiring together hardware devices and Internet of Things, but there are also plenty of modules for connecting to email, social media, various online services etc.
After using it during some months I can confirm that stability is absolutely fine, don’t think I have had a single issue with the setup due to Node-RED itself.
Version 0.10.1 came out a week or so ago (early Feb 2015) and brought things like better partitioning of flows in the form of subflows, improved Raspberry Pi support, binary MQTT payloads to name just a few of the improvements.
I am running Node-RED on an always-on Mac, running latest OS X. This machine is very stable but for various reasons I do need to restart it every now and then. It would then be very nice to have Node-RED start automatically at boot. That’s somewhat complex to do, but having an app starting at login is trivial – let’s do that instead. I am always logged into this computer anyway, so it won’t be a problem.