Simple/reliable wired light switch detectors with QLC / DMX / Art-Net / sACN?


I’m just starting to explore openHAB. I think I want to use openHAB, QLC and Art-Net/sACN to automate my home lighting but I’m new to all of them and need to get my head around the environment before diving too deep in the wrong direction.

I like the idea of DMX so I can make my garden and outdoor lights do cool stuff at night or at Christmas or Halloween etc (and inside lights too for fun or some practical stuff like making the burglar alarm scarier).
I plan to use RGB or RGBW outside. Inside I want to go for RGBWA as much as possible so the colour is nicer (DMX RGBWA downlights are available on Alibaba now). Hopefully openHAB + a sensor can help me detect the colour/brightness outside and change the colour/brightness inside accordingly.

Over time I want to end up with a house that does the lighting for us, not have to press a switch every time we move around. So there will be motion sensors and switches and switches should be mostly for scene changes. I’m new to this so being able to reassign switch functions is important as I screw things up and evolve them.

I want to keep all the existing (old school, AC powered) switches so everything matches. I guess it will take years to replace all lights and switches but there’s no mad rush and I need to prove it works in a couple of areas before the wife will accept it.
I’ve been looking for a reliable and relatively simple way to detect when light switches are pressed. I’m planning to change the wiring in my light switches from AC powered to CAT6 (I like wires not wireless).

Before coming across DMX / Art-Net / sACN, I was planning to run a CAT6 cable from each light switch to an Arduino board with ethernet shield, connecting the standard terminals in the light switch to input pins on the Arduino, and use MQTT + NodeRed to manage the logic. I would have several Arduino’s located around the house so that each one services a cluster of light switches (and temp, humidity and other sensors) and sends data back to the central MQTT broker on a RPi. Then the software decides what lights to turn on etc.

I’m hoping QLC will allow me to run occasional light shows using the house and garden lights, and make it easy to create subtle effects between scene changes (e.g work -> dinner -> movie -> bed etc).

So my 2 questions are:

  1. Could I use QLC and openHAB instead of MQTT and NodeRed for managing light switches?
  2. Are there easier, more reliable and cost effective options than the Arduino route?

Off the shelf products appeal for their potential ease of installation and maintenance, but the Arduinos appeal to my DIYers budget.

Thanks to Stuart for suggesting some nice looking Velbus products in this thread:

(Stuart - any problem using these in NZ and do you have a price list?)

What else is out there and what problems would the Arduino method be likely to cause?

Thanks for your help, and assume I know nothing,

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Hey Phil

That’s an excellent write up of what you want to do and how you want to achieve it.

Personally, I’d avoid any DIY push state devices, but only because my mind couldn’t cope with the delay in getting to the fun part.

As I suggested in the other topic, I’d put in a Velbus VMB8PBU behind the existing light switches and create yourself a Velbus network that to start with only has button events on it.

Then as you expand, you can swap out the older light switch for Glass Panels that include thermostats and better led feedback.

Maybe even put in Velbus relays and dimmers, or PIR devices.

There are other wired solutions available, but always compare Apples to Apples :wink:

I’ll send you a PM on this :smile: I don’t think there are any issues using Velbus in NZ, however we’ll have to check with your local electrical / heating installers / compliance team of the council.

As for DMX based lighting for the whole house, it is a much faster responding protocol designed for theatre and live event use, so you’ll definitely be able to achieve all manner of amazing effects.

These DMX controlled devices are maybe a bit too far, but I’m tempted to install one or two at home. (I’m not sure what the neighbours will have to say about it)


(Everything in there is DMX controlled, the colour, water height and gas release & ignition, so all potentially possible directly from openHAB2 or Node-RED, QLCplus gives you the ability to create really complex shows)

I assume you’ve seen the videos of one of my client’s homes, with his >7000 addressable LEDs?

Have a look on my YouTube channel.

Those fountain flames would look amazing on top of the hill behind my house (3000 homes would see it) but I’m not sure the council would approve of me installing flame throwers next to their bush reserve.

If I use openHAB and QLC+, would the Velbus VMB8PBU + VMBRSUSB replace the need for MQTT?
Would NodeRed still add some value some how?
I’m looking to minimise the layers.

How many VMBRSUSB modules would be needed, or can 1 do the whole house and you loop the cable around the whole house?
It’s a single level 210m2 house with reasonable ceiling access.


Hello Phil,

Councils always know how to “kill a buzz” :wink:

You could always install the water and light versions. :smile:

Absolutely they would.

openHAB2 and Node-RED can pull the the events directly from the USB connection (via a tiny TCP server applet).

(Node-RED can pull the Velbus events directly from the TCP server, or pull all the openHAB items)

That really depends on how complex you want your rules / logic to be and your skills with coding.

You might well be able to do everything with DSL rules, or the other logic solutions that are directly available within openHAB2.
(I haven’t ventured near NGRE or scripted automation etc yet.)

I have been able to do some pretty amazing things with DSL rules, with more than a little assistance from the fabulous people on here.

However, my mind finds the visual nature of Node-RED much easier to comprehend.

Just one USB interface would be fine, as long as you’re not planning on installing upwards of 200 Velbus modules.

You can install them all on single radials if you like or one big loop.
Even combinations of that which suits your installation.

Not many people opt for a Root and Branch topology, but in theory it would be fine.

The only issue with any of these is finding the sweet spots for the line terminators.
Every installation needs at least 2 terminators (bridging tiny jumpers on some modules, or closing a tiny switch) at (normally) opposing positions on the network, or in the cabinet and at the furthest point.

(Much like the old school coaxial 10Base-T data network line terminators)
It’s not a big deal, just something that needs attention during installation / commissioning.

Should be a walk in the park then…

You’ll have sound, video, light and HVAC control in every corner of your house / property boundaries in no time.

Good luck