Am I mad?

Hi All,

So first post on this forum and probably not the best question to ask as a starter. At the very least I’ve probably answered the question in the asking in the first place. Confused? That makes two of us.

But I digress.

So I’m about to embark on some renovations and want to incorporate smart home features into the build. Given that we will have internal walls and ceilings exposed as part of the rebuild I’m currently heading down setting up a proof of concept with the following goals.

  • Openhab provides main control
  • 12 volt led lighting controlled using DMX. My plan is to centralise the DMX controllers and then have 12v runs out to the LED’s. It’s a small house (less than 65 square metres) so long runs on low voltages shouldn’t be too much of an issue.
  • No manual override between the controller and the LED’s. That is, no light switches or dimmer controls physically in the path. Control will only be available via DMX.

So why this approach? Mainly because I’m on a budget and stuff like fibaro modules are expensive once you start talking about whole house implementations. Also, the new stuff on the market seems to be targeted at retrofitting existing homes using wireless connections to control mains voltage devices.

All in all it sounds pretty straightforward albeit with some pretty significant risks not least of which is the fact that my last serious attempt at programming was with turtle graphics on an Apple IIe. Personal issues aside I’m keen on feedback from the community around my stated approach. Some starting point questions as follows…

First and foremost. Do people think that openhab is ready to control house lighting? Having to reboot regularly or having lights not respond when a button is pushed would count as automatic (and catastrophic) failure. What are is your personal experience?

What do people think of my choice of DMX as the preferred option for lighting control? I’ve compared this option to X10 / Insteon, Z-Wave,m and ZigBee. I like the fact that it’s pretty proven and should be a lot cheaper to implement than the newer ‘Z’ options. I wouldn’t mind some feedback on DMX vs Artnet for lighting control in particular.

What are my options for a virtual light switch / dimmer if I don’t have a physical switch in the loop any more? Is this even a good idea or is the reality that this stuff isn’t reliable enough not to have a manual override? I’m thinking about the Insteon / X10 keyfobs available as an alternative to a real light switch. Anything else I could be looking at?

So there we are in a nutshell. Massive optimism, minimal experience, high risk, low budget, and no time. Please believe me when I say that your feedback would be very much appreciated.


I use openHAB with Z-Wave for 90% of my lighting control and can honestly say we NEVER use physical switches anymore. The lights come on when the light level in the living drops below a set limit, and turn off when we go to bed. And in between times if the house is empty they turn off, and come on when we arrive home. It works like a dream and we don’t even think about lights anymore. When it gets dark they are just on. When we wake up they are off.

Automation bliss ;).

So in short, yes I believe you can rely on openHAB for whole-house lighting control. But it all comes down to your rules and implementation. The technology definitely supports it tho.

Hey Ben,

Thanks for the quick response. +1 in the possibly not mad box then :smile:

It depends on your tolerance for control. I, like @ben_jones12 follow the HA philosophy that it should just work. If you have to resort to a manual control then it is a HA failure. That being said, there are some use cases to keep in mind. Do you need a way to override the automation (i.e. keep a light on when automation says it should be off and visa versa)? Do you ever want to manually control the lights otherwise or is complete automation OK?

For my setup I have a mere three lights on automation. Two lamps and the porch light. For us, these are the lights we want on in the evening for sure. The rest of the lights we would rather manually control based on what we are doing at the time. For example, if I’m reading on one side of the room and my wife is on the other, we might have all the lamps in the room on. But if we are sitting by the fire or playing with the little one, we may only want one light on. And because controlling lights from a phone is cumbersome (as cool as some people may think it is) all these lights remain traditionally wall switched or switched at the lamp.

Another question to ask is will guests ever have to interact with the system? I’m actually facing this problem soon as I have guests who will need to work the garage door opener but don’t have smart phones. I don’t have a simple button I can give them. HA failure.

Sit down and consider all of your use cases and I bet you will find whether or not what you plan will work for you. Technically it shouldn’t be a problem. I’ve found openHAB to be exceptionally stable, only ever needing to restart it when I’m changing certain configs. Some of the remotely deployed devices…not so much.

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Artnet is just another way of transferring the data. With Artnet, the data goes over your network cable, with DMX, you need DMX cables, which are more expensive than network cable. DMX cables have a shorter reach than network cable.

With DMX cables, you’ll need a serial to DMX adapter to drive it from openHAB. With Artnet, you’ll need an ArtNet-DMX adapter. An Artnet adapter is more expensive than a serial to DMX adapter (unless you would build it yourself of course), but IMHO is worth the investment. It makes it very easy to use any computer on your network to act as the ‘controller’, which is very convenient for setup and troubleshooting. Also, if you would ever want to install a standby controller which takes over if the first one fails, Artnet is the way to go.

There are also DMX din rail modules available for 220v, just in case you want to use DMX to control your wall sockets as well :wink:

Hey Rich,

Thanks for the reply. It sounds like the consensus at least is that Openhab is stable enough which is a good starting point.

With regard to full automation versus manual override I was thinking of having something like the Insteon / X10 keyfobs as a quasi light switch. I like the idea of combining automation with manual intervention still available but I don’t see why the switch needs to be physically connected to the lamp when there are (limited) options available to interact at the controller level instead.

Good points on HA. This was something else on my ‘want’ rather than ‘must’ list so glad to know that there are implementations out there already. Ditto monitoring and automated failover.


Thanks Davy. I’ve gotten as far as purchasing a serial to DMX adapter and confirming that I can control some lights at this point and am playing with a cheap 30 channel DMX control courtesy of my good but somewhat unreliable friend Aliexpress…

My plan at the moment is to have the controller(s) central and then run the power as opposed to having to run both power and control. The house is relatively small so the run length shouldn’t be an issue even with 12v.

Just an update (and more questions).

I’ve managed to configure OLA to the point that I can control my test light strip (Universe 0, Channel 3).

On to Openhab. I’ve made the following changes…

  • Copied the org.openhab.binding.dmx.ola-1.7.1.jar file into the addons folder

  • Added the following line to the openhab.cfg file. The IP address is the address of the pi I’m using to run ola

  • Added the following line to my bushbaby.items file along with a complementary config into the bushbaby.sitemap file. This is a single led strip running on channel 3 (not RGB)
    Switch RGB_gTEST “RGB Light” (gTEST, Lights) {dmx=“CHANNEL[3]”}

Running openhab I can see the RGB light as defined. When I try to switch it on and off nothing happens :frowning:

So nice easy question. What am I doing wrong?

Some additional info. I’ve run Wireshark on the Openhab server and can’t see any traffic exiting the PC bound for

Thoughts on next steps would be appreciated.


You also need the org.openhab.binding.dmx.jar in the addons folder.

Turning up debug levels will also help understand what is going on.

Thanks Davy. I’ve added the additional jar file as instructed. Looks like a step in the right direction. I now get the following errors when I attempt to toggle a switch off…

21:10:42.358 [DEBUG] [i.internal.GenericItemProvider:341 ] - Start processing binding configuration of Item 'RGB_gTEST2 (Type=SwitchItem, State=Uninitialized)' with 'DmxGenericBindingProvider' reader. 21:10:42.374 [DEBUG] [.b.dmx.internal.config.DmxItem:209 ] - Linked item RGB_gTEST2 to channels [2] 21:11:07.864 [INFO ] [runtime.busevents :22 ] - RGB_gTEST2 received command ON 21:11:07.903 [INFO ] [.binding.dmx.ola.OlaConnection:87 ] - Starting autobind for universe 0. To disable autobind use -Dnet.opendmx.ola.autobind=false 21:11:08.383 [ERROR] [ola.rpc.StreamRpcChannel :137 ] - Connection error: Message missing required fields: type 21:11:08.383 [ERROR] [ola.OlaClient :101 ] - Shutting down connection: Message missing required fields: type 21:11:08.383 [ERROR] [.binding.dmx.ola.OlaConnection:90 ] - Could not retrieve device list. Binding to OLA aborted. 21:11:08.399 [ERROR] [ola.OlaClient :85 ] - Cannot send data. No OLA connection available.

Next steps anyone?


Just to advise that I’ve added an Artnet input plugin on the OLA side and changed from OLA native to the Artnet plugin in Openhab.


For those who are following I’d still be interested in understanding why I can’t connect direct via the OLA addon.


The OLA java client which is used, only supports connections to localhost. If you run openHAB and OLA on the same machine, it should work fine.

To chime in with some thoughts… although I agree with the idea that the HA system should be self-sufficient and work, I think that there are certainly instances where it cannot be completely relied upon. If you are doing non-essential things like environment and security monitoring, then it is not the end of the world if the system doesn’t work properly. Lights not working at night when you have elderly guest staying at your place while you are away is however a problem.

Just to give you a couple examples of why my OpenHAB system has either gone offline or other major issues:

  • power outage fried its power supply
  • power outage fried the Ethernet switches power supply
  • SD card was corrupt and required repair on a Linux machine using e2fsprogs
  • OpenHAB upgrade replaced the startup script which told it to look for my USB serial controllers on non-standard ports
  • Java problem relating to serial libraries caused memory leak; eventually making the system completely unresponsive

I am not pointing at any one thing; just that stuff happens that may affect temporarily hinder your central controller. Perhaps I’m just unlucky. Some problems are really easy fixes, but the network outage due to the dead power supply required another power supply that most wouldn’t have on hand.

So, why not create more of a decentralized architecture, where you have a more basic embedded controller which is actually controlling the lights, and then you communicate with this from OpenHAB. This way you can take OpenHAB offline and the lights will still work. I am thinking of say something like an Arduino which would control your lights, and then the other thing would be to consider putting in momentary push button “light switches” in the walls which would be wired into the Arduinos inputs. These button presses could then toggle the light state; even for people who are very, very technically challenged.

You might also consider trying to have redundant power supplies feeding your DC power bus, and then power the embedded controllers from this bus. Then your lights and your controllers are covered in case of a problem with your DC power supply. It sort of goes without saying that you could battery back your lights and their control at the same time.

I have to admit that the fried power supplies do sound a little unlucky :smile:. The rest sounds like par for the course as far as what I would normally expect to go wrong on any given day in an IT environment. It also helps that most of these can be mitigated by good process and planning up front.

I can also see the advantages from an availability perspective in decentralising control and having a manual override. The challenge I think for me and what I am looking to achieve is that I would then have to either run wiring or use wifi to enable comms between the central control point (openhab) and the control devices along with separate power runs. Not too much of a problem if you intend to use mains to power your lighting but more problematic if you plan to go 12v as I do.

This has also made me think more about how I intend to put this all together. I’m currently experimenting using openhab as my rules engine with OLA (via artnet) as my controller and had been considering dumping OLA and going with a straight artnet adapter. Based on your feedback I will now probably keep the two functions separated and look to include an alternate artnet based interface so that, worst case, I can easily implement and ermergency lighting scene without having to invoke openhab.

In my experience there are a lot of things that can go wrong and there are a number of things that you can usually do to either mitigate or plan for. The one thing that I know I can’t live with in this sort of implementation is massively flaky software. Everything else I can plan for.

Good to know. I’ve done a couple of updates to the wiki based on your feedback to make these points a little clearer.

Awesome. Thanks!

Yup… apparently. :stuck_out_tongue:

You mentioned that it was a small house and that the walls would be opened up. For me this means that it would not be a big deal to put some Ethernet cable in place. This can take care of network and power if you want (we have recently been exchanging around this idea in another thread).

I certainly wouldn’t say that it is massively flaky… but it is a relatively complex system with a lot of parts to it.

Its late so a quick answer for now:)

I got 58 rgb leds hooked up to 8 9 channels custom made dmx modules(basically standard but with custom conector(rj11) and din rail mount). Untill now i have been using the dip switch for the ugly white light and relay just to cut the power off for each module to turn off and on my light.

However now i finally got ola to work(newbie to linux) so now i am on the progress to change colors:)

I will take some photos of my setup. Its work superb so far, I am using phones, tablet glued to the wall, ifttt rules, and physically switches, and amzon echo. I will add motion sensor at some stage. But to be honest, I mainly use echo.