Hello
I’m gonna build a smart home with raspberry pi 3+ which i have at home using openhab software. My plan at first is to control around 35 lights with relays, 4 temperature senzors and turnning off and on heating sistem(for all electrical i have an electrician). So my question is, is this possible?? And is it possible to add dimmer controlers for lights? And what parts would i need beside 3x16 relay boards, 4 temp. sensors.
Thank you
Jaka
Yes this is all possible but I would do some research about what devices you want to use and check the forum to see what works best with OH. I would recommend devices that are easy to setup and communicate via mqtt, without an extra hub, but that’s just my opinion.
1 Like
The most popular approaches is to go for either Z-Wave devices or Zigbee devices or both.
If you are set on relay control you will only get ON/OFF control.
I have grown quite fond of Ikea Tradfri Zigbee bulbs & panels. They have integrated dimmer and white color temperature control. Since each ligth is controlled individually it is very flexible.
Philips HUE is also popular, but a bit mor expensive, but most of their devices are RGB.
With any home control system, a backup solution is always desirable should the gateway (OH) go down for some reason.
For Z-wave many wall switches offer local control and for Zigbee many remotes can be directly associated to one or more lights.
If you are still set on discrete relay control, have a look at this.
2 Likes
Professionally speaking, I would always recommend a hardwired solution.
I can happily confirm that the Velbus range of building control modules work very well.
All that is required to get openHAB2 talking to Velbus is a USB connection and the Velbus Binding.
The version of the binding that is in development, also offers a TCP bridge if you want to simultaneously connect other software to your Velbus network.
For example the Free VelbusLink configuration software.
For more information, please take a look at the official website.
Or the YouTube videos
I’m happy to offer technical support to any openHAB2 & Velbus user.
2 Likes
@MDAR if your house is under-construction wired is more reliable solution, but if it is not I believe wired will be hard to apply.
What do you think ?
1 Like
Security company’s install sensors everyday, in existing homes, it may require a little work but it’s possible and worth it. Just my 2 cents.
1 Like
@H102 I think it depends on the home construction status. for example if there is false ceiling maybe it is possible. If it is possible in any case, so why someone will use wireless equipment?
1 Like
@a.tibi touche Ahmad, but what equipment works without power. I know there are many battery powered devices but why bother if you can supply it via hard wire.
1 Like
I’m loving your conversation 
Retro fitting is never easy, but with some careful planning, it’s not impossible.
Given that most wired solutions require a control bus, rather than a Spoke & Hub topology, once you can identify how to get dimmers and relays in place to control fixtures / devices, placing a single cable control bus around a property becomes the easy bit.
For example, a careful slice of a wall / plaster surface to sink a thin cable is achievable.
For example, my own home (a 1884 semi detached) has multiple Nodes where control hardware is located, with a common bus linking them all together.
Each Node only requires some mains power and Velbus data.
1 Like
What’s the average price using Velbus modules in a home, no wiring, just the modules? I’m asking for a guesstimate, as with every home, and person it will vary.
1 Like
As it happens…
I did a quote last week that might be nearer to ‘average’ than a lot of other jobs we’ve done so far.
This client has asked for…
4 heating zones, with a boiler interlock (so that valves can be moved during summer months) - VMB4RYLD & VMB1RYNO
8 switched lighting circuits (switched circuits rather than dimmerable) - 2 x VMB4RYLD
1 Window motor controller &
1 Blind motor controller - using a dual channel controller - VMB2BLE
1 Glass Panel with an OLED display (up to 8 pages of 4 buttons) - VMBGPODx
1 Four button glass panel with built in PIR - VMBGP4PIRx
2 Two button glass panel - VMBGP2x
1 Single Button - VMBGP1x
(FYI
Every glass panel has a full HVAC thermostat built in, as well as multiple fully programmable timers, with 3 groups (Summer, Winter & Vacation))
Each quote includes, a PSU, USB interface, connecting rail for DIN mount modules and… An ODroid SBC to run their UI of choice.
This quote came in at €1527 + VAT & Postage (Full Retail)
That’s not so bad.
1 Like
Indeed it is.
Especially when you try to compare the functionality and ease of commissioning of Velbus modules against other products.
The hardest thing we face is getting clients (or rather our client’s clients) to realise that its difficult to directly compare competitive products.
“Price isn’t everything”
@MDAR if someone buys a home with a security system previously installed, could the existing wires be used with the Velbus modules or is it best to run now wire?
There’s an interesting question…
Assuming that the security cables are redundant, then… Maybe…
Velbus only needs a 4 core cable.
1 power pair (~15v)
1 data pair (Similar to Canbus High & Low)
There isn’t any strict rules as to the topology, so as long as there is continuity of the 4 cores at all points around the property, you ‘should’ be okay.
In an ideal world, we’d like to see a cable that contains 2 x stranded twisted pairs, roughly 24awg.
Like an EIB / KNX / AMX / Crestron.
But I’ve seen people use 8 core alarm cables, ran in radials (hub & spoke) and CAT5 cables in a big loop.
As long as line terminators are positioned careful, we’re yet to see a system we can’t get working 
I use 22 awg mostly, I’d have to use my teeth to strip 24awg back.
but it’s good to know that smaller wire can be used.
Thanks
1 Like
I can post you some tiny wire strippers if you like 
The purchase & postage will cost less than a dentist’s bill
I’ve seen Velbus systems work happily with single cores of Cat5e or 2 pair telecom cable.
(I’ve also seen the cores fracture due to the rising cage clamps being over tightened, but let’s not go into that)
1 Like
Next time you open a can of beer feel how sharp inside the mouth is.
Honey, I need some more wire strippers, this one’s getting dull.
So a method with relays will work, but can i add a Arduino light dimmer? And one stupid question(first time using raspberry gpio) how can i connect 3 relay boards with 16 relays, few valve motors, humidity senzor and temp. senzors all to the raspberry pi?
Hello,
New user here with a first post.
I have been lurking around openhab and it really looks good to me. I evaluated the bindings and decided that the Velbus line of products was the most appealing to me and my sensibilities. I’m at the stage of trying to purchase some Velbus components but I’m starting to think that aren’t readily available in the USA.
Are their ways to get Velbus products in the USA.
I really appreciate the combination rawness and thorough and simple messages that Velbus provides so I would consider other products.
Thanks,
Ben
1 Like