DMX lighting control options

[dnb]

I have seen DMX discussed here before - I think it was @joth doing an installation using Loxone controlling DMX?  If this is correct, what DMX decoders did you use, and are you happy with them?

 

I have just started to look at lighting control schemes and pretty much decided DMX is the most sensible standard because it's most unlikely to go away any time soon or be depricated at the whim of a single business. I have bought a few DMX toys - a cheap USB interface and a few decoder boxes and had great fun making computer controlled LED strings using an old laptop - so I am happy with DMX responsiveness etc and it's not exactly expensive in the grand scheme.

 

But what ways are there to provide the human inputs so that normal people don't hate visiting?  Loxone is an (looks good but very expensive) option of course, but it does seem to be going closed shop so I would prefer cheaper and more open if it's possible. What else that supports DMX is out there? Preferably not involving wifi or anything that can't run properly on an airgapped network.

[joth]

Yes I'm midway through a DMX install. I built up the LXN5 cabinet during lockdown part 1, 32channels of mains dimming and 48channels of LED 24V dimmers, plus some relays and options for constant current dimming.

 

Starting 1st fix next week and currently panicking that my lighting design is inadequate/inappropriate/unimpressive and getting a professional designer to review and improve it so all subject to change! And real recommendations will need to wait 9 months until it's been in and used a while. But in meantime these are the parts I used and happy so far (as in, they all appear to work)

 

https://m.aliexpress.com/item/4000831173626.html

 

https://m.aliexpress.com/item/32837953011.html

 

https://m.aliexpress.com/item/32445284627.html

 

https://m.aliexpress.com/item/32444739690.html

 

https://m.aliexpress.com/item/33040978707.html

 

 

 

The final one is a dmx splitter which is very useful to allow branches in the bus, and avoids power on noise interference between the branches. The triac mains dimmers have about 2W standby draw do to save on 30W of base load I power them off completely with a relay when unused, but the do judder a bit when powered up.

 

The mains stuff I wanted CE marked ("Chinese Export" scam as it is) and enclosed, but low voltage stuff I'm increasingly comfortable buying the boards and squeezing into my own DIN enclosure.

 

 

 

Not sure I can help much for non loxone controls. Fwiw a minimal loxone install would be about £700 for a miniserver, 20 way Digital input, and a dmx bridge. To get value from it you at least need some motion sensors too, I'm using https://m.aliexpress.com/item/33001159734.html but with the noisy relays removed. 

 

Non-loxone wise I think the options for DMX are either completely proprietary professional install (control 4, high end lutron etc) at which point the control protocol behind it is fairly academic to the user/owner, or completely home brew perhaps using something like Home Assistant and an ethernet to DMX bridge. That needs internet access for setup and remote management, but otherwise should work on an airgapped network after a fashion. But again if going that route I might forgo the DMX completely and just use esphome flashed onto Tuya based smart light bulbs and so forth.

 

The elephant in the room is KNX, being standards based and open with a lot of light switch vendors supporting it, it should be the obvious answer to work with. I found it more expensive than loxone, less appealing end result, and far far less inviting to self install (even with the loxone trend towards discouraging self install) but I know others have made this work for them. Most find DALI fits the KNX ethos better than dmx though (less centralised? More tunable white support?) but again that jacks up the costs.

 

Finally, I think you can get DMX colour mix wall switches like https://www.google.com/amp/s/h5.aliexpress.com/item/32693927499.html but that honestly looks a mess and like it locks out all the benefits of home automation, but could be ok as a "get me started" choice.

 

 

 

Someone once said words to the effect "home automation lighting control industry is a mess" and this still very much holds.

 

 

[dnb]

Thank you @joth. That's just the sort of information I was looking for. Especially with the hardware side. Not liking the 30W permanant draw!

 

I've considered my requirements in light of your post (pun intended) and concluded that I do want centralised lighting controls. Mainly because I want the switches to be able to configure the house for what we are currently doing rather than because we are in a particular place. There is a temporal consideration too - for instance SWMBO is disturbed easily by hallway lights at night, and I am a typical night owl. So I would prefer that the system could centrally decide to have a "night mode" at a particular time where everything is dim or biased to red. Such things need to be configurable as a global setting and not be something per light fitting.

 

I was playing with Freestyler today and it turns out that it can receive windows API calls or UDP packets as control inputs. This means at worst case I could roll my own very simple ESS32 microcontroller switches that transmit wifi packets to a windows PC running Freestyler on an airgapped network to control everything. (I could even use a smartphone app to do this). It's clunky in the extreme but very cheap.  Not suggesting this is actually a good option , but it is relatively low risk in terms of vendor support. And it lets me continue testing on the cheap for the moment.

 

I am really trying not to roll my own solution here. I've simply not got time unless I can convince SWMBO to make use of her software engineering degree (she's said 'no' very pointedly in the past)! I have to confess that I really like the Loxone switches. They represent a near perfect interface for what I want to achieve. Oh well, budgets are a bit elastic aren't they?

 

You are of course right. The industry does seem in a mess. It appears to not be able to be pulled in a sensible direction at the moment. Where sensible is defined from the end user point of view, not the revenue stream.

[Hilldes]

@joth How did you get on the with Aliexpress DMX dimmers 12 months later?

 

Can I also check please, is it correct that just these items are required for 230v dimming:

 

Loxone DMX extension

S1-DR AC Triac DMX Dimmer 2 Channel

 

Note the 240v triac dimmer you originally linked appears out of stock, but the one I linked here looks equivalent.

[joth]

2 hours ago, Hilldes said:

@joth How did you get on the with Aliexpress DMX dimmers 12 months later?

 

Can I also check please, is it correct that just these items are required for 230v dimming:

 

Loxone DMX extension

S1-DR AC Triac DMX Dimmer 2 Channel

 

Note the 240v triac dimmer you originally linked appears out of stock, but the one I linked here looks equivalent.

 

Yes that's the ones. They work fine, but have 1.5W vampire load each which over 16 adds up (and makes the cupboard quite hot). You can mitigate this by using a higher powered SSR to shut them all off when not in use. (Loxone makes this very easy to do).

Anyway  I replaced most with the UK designed 2x16 channel dimmers.

http://whitewing.co.uk/acdim.html

 

These are much more efficient, energy and space wise. Only downside is much lower power per channel, and they do make some LEDs flicker a bit if loaded near their current limit and running at half brightness. 

I've kept a few of the 2 channel AliExpress ones for a few higher power applications.

 

So I've got about a dozen of those AliExpress ones spare if you want them for 50% of whatever they're charging for them new?

 

 

[Hilldes]

Thanks @joth. I got a quote from whitening a few months back for the 16ch dimmer at around £480 that is £30 per channel. Low cost though compared to the Loxone dimmer at around £120/channel. 

 

On the Aliexpress S1-DR vampire load, how will Loxone know that a dimmer is not in use? When this is detected, you use a relay to break the 230v Live supply at bottom left on the unit labelled "AC100-240V Input""?

 

 

P.S. I would be interested in some the spare S1-DR dimmers you have if I go down that route. Will PM you.

[joth]

1 hour ago, Hilldes said:

 

On the Aliexpress S1-DR vampire load, how will Loxone know that a dimmer is not in use?

Loxone is driving the DMX dimmers so knows when any channel on it is set to >0 brightness, so you can split this out to a big OR block to say "if any of these DMX channels are non-zero, turn on the relay to power up the dimmer bank"

I use something similar to shutdown the 24V LED lighting power supplies when not in use:

 

1 hour ago, Hilldes said:

When this is detected, you use a relay to break the 230v Live supply at bottom left on the unit labelled "AC100-240V Input""?

 Yes that works fine. 

One tip is as dimmers work by modulating the L feed, not N, I did figure out I could route the N from the LED fixtures directly back to the RCBO not via the dimmer, and then if I used a relay on the N terminal of the dimmers only it was only having to switch a much lower current (i.e. just breaking the current needed to power the dimmer internal logic, not the current needed to drive the LED fixtures themselves). This is a sneaky trick though (generally switching N is frowned on, right).

 

I'll look out for the PM ? 

[Hilldes]

Thanks, @joth really helpful. I suspected it was logic in Loxone Config - this will save time and head scratching.