I’m new to this community and therefore appologies if I missed something in the search, but the sheer content is a bit overwhelming and maybe I’m missing the right search terms.
I’m searching for some cheap and compact smart switches to control my roller shutters. I have the wires all in one central place and need to power the shutters from there. Size is a factor (as I have to fit 18 x 2 channel switches in the compartment). I had hoped something with din rail exists with 1HP per 2ch.
As the rest is not yet existing I’m open to all technologies as long as I can integrate them with OpenHAB
So far I’ve found
Sonoff stuff which seems to be “flashable” (they have 2ch and din rail 4ch) but 15cm for 4ch is quite space intense
There’s also KNX to have multi-actuators, but if you already find those other options ‘expensive’ then you’ll not be interested in KNX anyway. And there’s vendor specific RF based solutions, but you shouldn’t bother going with these.
Don’t stare at per-device prices and if they fit on a DIN rail. Those are no important criteria for a decision on technology. It’s only German electricians to really care about rail mounting, noone else does, that’s why devices to fit on there are more expensive than non-rail ones are … I also have my shutter wires in a central location and actually use non-rail ZWave actuators hanging off the rail - they’re cheaper and even smaller.
Also remember to compare functions and system cost instead and be aware of implications of selecting one technology or another.
A warning: don’t go with DIY relays or software-DIY like the Sonoffs - you’ll spend a lot of time calibrating and synchronizing on the software control part, and it will still NOT be working satisfactorily.
And they don’t have the ability to calibrate shutters nor to drive to a percentage nor to control venetian blinds.
And while Sonoffs have 2 channels, you also need 2 channels to operate one shutter, so they’re not really that much cheaper. Not worth saving the money here.
Homematic is proprietary stuff that can’t do some of that either, and it will lock you into that vendor, plus you will need a gateway. While you’ll also need a gateway (USB stick) for ZWave, that’ll provide you with a lot more choices in devices, vendors and further applications beyond roller shutters.
I’d recommend using Fibaro FGRM-222, ~45€, a lot of OH users around that are happily using it.
thanks for the detailed response. Yes, KNX was crossed off the list quite early
Just a few remarks, I think I have to stare at per-device prices. We’re talking about 810€ vs. 200€ for the Sonoff vs. 20€-50€ using the already existing Raspi + some soldering
What I didn’t understand is the “calibration / synchronization” issue? Currently I have two manual switches for 2 rooms as an interim solution. I just hit the switch in the evening and the shutter goes down and at the end the Somfy shuts itself off (the switch stays on). Then in the morning I shut the switch in the other direction. Nothing to synchronize here. With any switch I would set the “on”-time to something like a minute and then it can switch itself off. Should be enough, right? Of course I’m aware that something like shut to 30% won’t work with that. For that I would need to time each shutter, but nothing undoable.
By the way thanks for the Z-Wave Fibaro, I had seen that and for me it was roughly the same as the Homeatic HM-LC-Bl1-FM - my dad has a Homeatic system so I’m familiar with those and they work pretty well. A big plus vs the Fibaro is that they have inputs for switches so I can manually override if needed.
Regarding systems: I thought I choose OpenHAB to integrate multiple systems, so I was thinking that I get an Homeatic gateway / stick as well as a Z-Wave and others if needed. The Homeatic stuff is now open sourced and they offer the CCU part even as complete software solution based on a Raspi + HAT. So while the protocol is proprietary (but nearly fully reverse engineered) the software is not.
Thanks again for the insights, I think I will go with either the HM or the Z-Wave stuff and will look around a bit, maybe there are a few other options in the Z-Wave world similar to the Fibaro… Or I’ll get 1 Fibaro and one HM and compare them
You don’t, that’s a bad advisor in selecting a technology. What I keep telling people is that total cost of ownership is way more than the sum of device costs. You need additional gateway HW and SW.
You’ll need to spend many hours on writing software and testing (and you’ll greatly underestimate this, too).
Think of efforts it takes to replace broken devices (even if you don’t have an electrician do it).
FWIW, Sonoffs are known to be ‘burners’ in a literal sense.
I could well go on with a number of hidden and underestimated cost…
No that’s where many people to build shutters for the first time are wrong, they’re lacking the longterm experience. As soon as you do more than 0%/100% only (and once you can do that, you will want to use it), you will have to track states.
To do that using timing in OH doesn’t work reliably because there’s a number of unpredictable and incompensatable effects. OH isn’t realtime and network communications isn’t either.
This always results in shutters and OH to believe what state they’re in to get out of sync sooner or later, so you’ll need to re-synchronise them. Mechanical wearout over time and due to temperature changes is another reason you need to resynchronize (“calibrate”) shutters at regular intervals.
That’s why you will want to have that timing and calibration capabilities to be built into the devices.
Wrong, FGRMs have switch inputs, too.
The major pain point with Homematic is it’s proprietary at its worst. This will result in a number of problems in the long run.
eQ-3 has a questionable policy when it comes to compatibility and third party systems support. They do not care about or might even choose to deliberately break OH compatibility as did some other companies (see e.g. Loxone/Modbus for a bad example what can happen).
And once in you have to stay with their products, no chance of replacing if it turns out to be unreliable in electrical or mechanical terms or if there’s a bug they don’t fix.
I don’t see a reason why I couldn’t control one shutter with a Z-Wave and another one with an HM. But I agree using a dedicated roller shutter module is better than the homemade variant. As the Z-Wave is a bit cheaper anyway, I guess I will start with those and see where it takes me.
Sure. But why use two systems when a single one does the trick ? Two gateways to buy, two subsystems to configure, more SW complexity, less synergies …
Actually IMHO the ONLY reason to go for Homematic is investment protection i.e. to keep using devices if you already own them. But I’d never buy one when I have the chance to start from scratch.
Well, I’m currently pondering how to control my floor heating And there I had my eye on the HmIP-FAL230-C6 but I wanted to start with the simple things first (aka shutters). But you’re right, keep it as simple as possible.
Heating is way more complex but in principle, the same story applies.
I’m using ZWave relays to control my underfloor valves (a 6-fold Greenwave plug rail which is even cheaper than the HM one). Plus Zwave multisensors to include temperature in every room.
No. As said it’s just ZWave relays connected to valves (these) and ZWave temperature sensors, although you can use any OH compatible device as relays and sensors or even combine them from multiple technologies.
Either way, key is to have a comprehensive concept to properly cooperate with your existing heating controller. Any heating setup is always a pretty individual thing and you need to program your own OH rules.
Check out this post for a software framework.
Anyway, this is getting off-topic. Open a new thread on that if you have questions to the community.
Just be aware Shellys and Sonoffs are WiFi, so potentially you might be encountering issues with radio range, and they’re in danger of being attacked from the Internet, both of which you’ll not have with Z-Wave.
I guess that anybody working on home automation will or should be interested in having good wifi. Everything is hackable, I started off with 433MHz gear that my neigbour could control when sniffing for transmits. Having a good firewall (that blocks all unknown traffic inwards and domotica traffic outwards) should be a good start to protect you. I guess most people also have PC/PI connected Z-wave dongles which again creates vulnerabilities towards hacks from outside.
Of course it’s always good to think about security, but having shellies myself I can say that their size/performance/prize are very good and as far as I know incomparable with other products on the market.
The wifi connection risks (Shelly has the ability to add an extra user/pw layer to their interface) I’m willing to accept. (No direct connection whatsoever, just really satisfied with the product)
The Fibaro is 45€. So your house and personal safety is just worth 25€ ?
Ouch. Price should never be an argument to ignore security concerns.
No system is 100% safe but I wouldn’t be afraid of some high-tech burglar or hacker to target you.
The most predominant danger is getting hit by some botnet like Torii.
That’s where ZWave is way less in danger of because you cannot directly address the devices, and most of the time it’s about holes in intentionally opened interfaces, so even a firewall won’t help.
Don’t get me wrong, WiFi devices work fine and everybody is free to choose any solution for himself.
But you should be well aware of the consequences and only take decisions after you thoroughly factored in all of them.