More open alternatives to KNX?

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In progress of building a house and have been investigating home automation ecosystems. Broadly my requirements are, in order of priority:

  1. Wired or mostly wired for core functionality (e.g. I don’t care if blinds stop working once in a while but lighting, heating and HVAC must be rock stable);
  2. Must be decentralized (i.e. no cloud; I’ll have a home server, but would rather things continue working when that inevitably goes down too);
  3. Either cheap or extensible with proper planning.

And so KNX appears to be like a good option, but it isn’t cheap. What really doesn’t sit right with me about KNX, though, is the encrypted component database and proprietary Windows-only tools. Seems like a weird place to spend some inconvenience points at. Especially given that I’m a software engineer and tinkerer by profession, so I will definitely want to fiddle with the automation extensively and craft my own components too.

As thus, are there any alternatives to KNX that are more open to tinkerers?


If this isn’t an invitation for me to bang on about how amazing Velbus is then I don’t know what is. :smile:

If you search this forum for Velbus, you’ll see plenty of my cheerleading for it, as well as plenty of good news stories from other people.

While the binding is still a work in progress, the current .jar version file is pretty amazing. (As opposed to the version that gets installed from the OH bindings repository, which is still good, but missing lots of good things)

There is also lots of support available in the Velbus forum, but don’t be put off by the lack new threads, this is because the stuff just works.

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KNX is the only wired, at least somewhat open system. It’s well-defined and you have a choice of vendors. The only annoying thing (beyond pricing) is the habitude to make money with licensing and certifications only to electrician “experts” (duh!), depriving the public of specifications and documentation, leading to a need to use a proprietary admin software to setup the system.
Then again, you won’t need that any more once you equipped your devices with addresses and OH gets in charge of control.
The remainder of systems on the market, albeit often cheaper, are proprietary. Only interoperable with themselves, so you have to buy everything from that vendor, with all the other risks associated to proprietary systems (lack of bugfixing and support, hidden cost on expansions/upgrades, vendor to abandon products or to go out of business etc etc).

What’s the physical medium used for Velbus? Wasn’t able to find information on that. An ideal answer here would link to a specification that includes a description of a protocol used over that medium.

Also, are there any other vendors who produce velbus-compatible hardware? A fair amount of value proposition for KNX is that your preferred manufacturer can go bankrupt, pivot into beer making or whatever else it wants and you still would be able to buy compatible components from somebody else.


If these are deal breakers for you, then Velbus isn’t the answer you’re looking for.

Other answers you’re looking for can be found in these links —


Part 1: Hardware and Cabling

Part 2: Configuration

Specific technical documentation is available via links at the bottom of each module page, including a FULL protocol use explanation for that module.

The protocol is fully documented, which is why it’s been incorporated into OH and other platforms. (To differing levels)

Well, they aren’t necessarily deal-breakers, but it will necessitate looking into velleman more deeply, which is a different kind of pain in the back end.

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I’m certain the effort now will pay off.

Prior planning and preparation etc etc

If there are any questions you have about Velbus, please feel free to ask, either here, or via a PM.