Cheap Dimmers/Switches/Motion Sensors? Which protocol?

Hi there,

I want to further extend my Smarthome with more light switches, motion sensors (to turn on the lights) and dimmers.

At the moment I have some Homematic switches and dimmers and while they work great, they are rather expensive.
The protocols/dongles I currently use are: Zwave, RFXCOM, Homematic

Can anyone suggest cheaper switches, dimmers and motion sensors? Ideally they would fit into a standard socket (EU, I have Berker switches at the moment).

I’m unsure about WIFI (Sonoff etc) I think I would avoid it for now as I don’t really think that having those devices im my WIFI is practical.
It should be secure though in any way.

Thank you,

The Shelly switches are small and fit well behind an existing wall switch. Shelly allows you to continue to use an existing switch and connects by either wi-fi or mqtt. Their similar to a sonoff but rated for 16 amps and no flashing of firmware needed (note, you can flash other firmware if you desire). In the US amazon has Shelly 1 switches 2 for $23. For dimming take a look at the Shelly site I think they have others devices available that will do dimming but I have no experience with them.

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If you want to get away cheaper than these there’s only WiFi (Shelly or Sonoff).
But these come at a price (much more vulnerable because they’re IP devices, none to run on battery, …).
Cheap, secure, reliable - pick any two.

well then - what are the cheapest alternatives among the others? (non-wifi)?
That would be my question :slight_smile:

Go search the internet yourself please. Good devices are mostly the same level around 50€.
433MHz are cheaper but it’s less reliable. You may find some Chinese ZigBee based systems for less but there’s not much beyond lighting and again, there’s a price you’ll have to pay (interoperability for instance).

I’m sorry but this is a discussion forum, and I know that I can search the internet, I just have not yet the broad overview others might have, so I thought I would just ask someone that already made these choices, for their opinion or suggestion.
That’s the purpose of a forum, so I’d like to still post these questions even though I know that I can theoretically do everything myself.

I am on the same boat. For the lights, I use fibaro modules behind traditional switches since I believe the offer the best user experience. But they are expensive. Trying to deploy them to every single switch is a heavy blow on the budget. (plus all the other modules for different purposes)

I have the impression that if you go for all the well known protocols (zwave etc) they are all equally expensive. All the suppliers are quite aligned in their prices so there are not many choices left (I do not want to go for wifi solutions)

I wish somebody proves me wrong though :slight_smile:

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As frustrating as it is, there are none.
WiFi is noticeably cheaper, everything else is on the same ‘expensive’ level as your ZWave and Homematic are.

That I gave with my answer.

To add to that, there’s also the various proprietary systems (some of which might be cheaper but their main drawback obviously is that they ARE proprietary) and DIY solutions.

But while (eventually) cheaper, a simple direct comparison to ZWave or ZigBee obviously isn’t possible or at least not fair.

Of course, everybody does. But noone can unless you’re willing to strip down somewhere (functionality, safety, replaceability, reliability, compatibility, …).
There are cheap solutions for specific use cases but you weren’t asking for that but about technologies in a general sense with nothing but a price focus, and on that level there is no secret insider’s tip.
You get what you pay for.

That’s why I only buy those expensive modules and not cheap ones. Because I do not want to make any concession. But I have the impression we do not only pay that much just because of quality. There are probably too many factors that define the prices (royalties, proprietary/expensive hardware/software, niche market where the economies of scale do not apply etc etc)
But that is another story

So unless somebody proves me wrong, we are stuck for the time being with expensive modules.

Update to my own thread: It seems as if the Neo Coolcam Z-Wave devices are around ~15-20 EUR cheaper than others, so I guess that would be the cheapest alternative I have come across yet.

Are there any caveats?
Edit: Reviews are not really good :slight_smile:

I think this is the biggest reason that wifi switches are cheaper than the alternatives. In Canada, wifi switches and plugs are more expensive than in the US, but easy to find. Meanwhile, ZWave and Zigbee devices are much more expensive and hard to find. There’s just not enough demand here to drive down prices, and it’s possible there never will be. It’s Beta versus VHS.

Personally, I look at reliability first and price second. It’s not worth saving a few bucks if the device is going to give you more frustration than satisfaction.


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This is a switch with a motion sensor integrated. Ist it possible to integrate on openhab?

I’ve been happy with Xiaomi Aqara devices:

  • Zigbee based
  • Battery powered (button batteries) and it seems very long lasting
  • Small
  • Looks good
  • Cheap (US$8-$12 per device including shipping - need to hunt arount for the best price on aliexpress though, but I usually receive it within 1-2 weeks)

Devices include

  • PIR sensors
  • Buttons (single click=toggle, dbl click = toggle full/minimum brightness, triple click or shake = toggle warm/cool, hold=dim up/down). I also use this as my door bell.
  • Temperature/Humidity/Pressure sensors. I’m using this to turn on my shower exhaust fan.
  • Reed switch / open/close sensor
  • other stuff I have yet to acquire

There are zigbee lights too - I tried Ikea Tradfri but not happy with it. I’m happier with Wifi based lights flashed with Tasmota.

Not cheap, but I’ve been happy so far with UPB (Universal Powerline Bus) devices. They’re available as plug-in modules or in hard-wired versions. A little bit laggy on latency – they communicate at 4800 baud over the house wiring, with a 100 to 150ms delay before a UPB device responds to any command – but so far very reliable. More details about my UPB setup & experiences here.

On costs – for the USA & Europe I think the high per-unit cost of powerline home automation devices is a combination of 2 main factors:

  1. Low market penetration (home automation has been a luxury item / niche market until very recently.)
  2. Costs for safety certifications, e.g. UL listing, etc.

The actual manufacturing cost of the devices – after they are fully designed, tested, and approved – is probably a small percentage of the retail price, but the low market share means the retail price has to be high to amortize the upfront hardware development, certification costs, and ongoing marketing / distribution / support costs.

To some extent all consumer electronics are subject to this cost structure but when you’re manufacturing & selling 100 million GFCI outlets or 5 million electric hot water kettles, economies of scale often permit lower unit cost.

Perhaps the biggest barrier to broad adoption & subsequently lower cost for permanently-wired line-voltage home automation switches is the fact that 99% of electrical work is done by professional electricians, usually at the time of construction. I think there will have to come a tipping point at which HA-enabled line-voltage hard-wired switches become a common option in new construction – the way GFCI’s are now, for example. Not holding my breath for that to happen; most improvements to the default electrical design of residences is driven by safety considerations balanced against keeping the costs as low as possible.

There’s also the reliability factor — building electrical infrastructure is expected to be 99.999% reliable. Looked at from the installer’s perspective, why complicate a simple, cheap toggle light switch by putting a $50-$80 “smart” switch in that is far more likely to burn out due to surges or component aging?

I’d add in the price factor. If you’re an electrical contractor bidding on a large-scale project, you’re going to specify equipment that meets the requirements with the least overhead and hassle. Given how unsettled the landscape is, it’s better to leave the choice of automation technology (with additional cost and risk of unreliability) to individual owners at this point in time.

Major trends in tech adoption are driven by the changing shape of cost curves. For example the first decade or so of cellular phone tech, low volume and low deployment dictated that only the 1% had them. S-curve transition came when the technology advanced to the point where the unit cost of manufacture of the phones (not to mention the cell site equipment) dropped so low that it allowed big companies to capitalize the production of first 10s, then 100’s of millions, eventually billions of devices, and get the pay-back on the investment over a long time span of guaranteed return. (People need to talk, ongoing.)

It’s interesting that Powerline Control Systems, which is from what I gather the originator and core developer of UPB, comes right out and says (page 4, last paragraph) in their "UPB Technology Overview" (published in 2005, apparently):

“The UPB technology can be implemented for as little as $4.00 per node, for two-way communication components including the UPB™ royalty.”

A couple of major structural factors stand in the way of the mass adoption needed to propel prices steeply down:

  • End-user demand expectations. The majority of people live in small or modest-size residences where it’s just not that big a deal to get up and turn a light switch or fan on or off by hand. Up until very recently it was only large properties, esp. multi-story single family homes, where the high initial cost of HA gave important early returns.

  • Expectations are beginning to change in the age of more-ubiquitous and better-integrated HA systems with Google and/or Alexa compatibility, Wifi/Zigbee/Z-Wave etc. eliminating the very high cost & difficulty of hard-wiring, etc. In a context where there are many HA-enabled devices even in smaller homes and apartments, consumer psychology starts to favor a growing expectation that 120/240V line-powered devices and switches will also get drawn into the HA fold. But this hasn’t happened yet.

  • Security. To my knowledge, none of the current powerline control systems (UPB, Insteon, X10, etc.) have any security to speak of. Their keys, ids, “passwords,” on a per-device basis are merely used to prevent immediate interference from neighbors within the same RF and/or power line carrier signal range. In this day and age, and looking at scenario where millions and millions of homes have HA systems integrating powerline control, much stronger security is needed. This of course means various forms of encryption which means more CPU/RAM/NVRAM storage needed on each device, and a much higher level of development expertise needed in design, implementation, testing, and long-term troubleshooting / damage control. (Imagine if say 30 powerline-controlled hard wired switches in one’s house got “hacked” and there was no way to conveniently update the firmware… Might cost $10-$15K to replace and re-wire every outlet, switch, etc. (Here’s an interesting discussion of UPB’s security limitations.)

  • And, restating what we’ve already discussed – the inherent and useful conservatism of the electrical trades. Electricity in developed nations is expected to be 99.9999% reliable (when properly spec’ed and installed.) It’ll happen eventually but it may be another 10-15 years of development until HA-integrated hard wired devices can reach that level of reliabilty, and be secure, and be affordable.

UPBTechnologyOverview 051216.pdf (138.1 KB) (for historical purposes in case the live URL listed earlier expires.)

Re: Shelly™-brand switches, wow, I had not seen those before. Very impressive package & features at that price point, and with EU electrical certification. A factor of 200% to 600% cheaper than UPB switches is a powerful incentive to investigate further.

A few thoughts after a brief but close review of 2 of their relay and dimmer controller units’ user manuals:

  • USA code-compliance issues? Not sure if/how the US NEC and state codes handle EU-certified devices. Must be OK because Shellys are for sale in the USA?

  • Assuming good hardware & firmware, Shellys should do fine in a well-designed & installed WiFi environment. Good-quality WAPs (e.g. Ubiquiti) vs consumer-grade junk would probably make a big difference.

  • Wifi-based communications entails all the normal gotchas with Wifi. Range/packet loss problems just due to distance, possibly due to interference in a noisy WiFi environment, security issues with IoT devices that talk to the internet, etc. For example it’s not reasonable to expect that IoT devices are going to support WPA3 soon or en masse. In my view the best / probably only effective way to secure WiFi IoT devices is by isolating them on their own dedicated Wifi LAN / SSID with appropriate firewalling & proxying between normal user Wifi & the IoT LAN. Beyond the scope for many HA enthusiasts.

  • The Shelly™ series should work reliably (assuming a good overall WAP placement, signal quality, etc.) as long as they are installed in plastic electrical boxes. I tend to doubt that Shellys would communicate well if installed inside of solid metal electrical boxes.

  • Very thoughtful design includes the ability to attach hard-wired switches to control Shellys in case WiFi behaves badly or stops working altogether.

  • Standby power consumption spec’ed at 1.5 watts for the smaller Shelly devices. 10 to 20 of these devices would add 15 to 30 watts to a building’s vampire power load. Could be a factor for some people. (I’m not sure how UPB, Insteon, X10, etc. compare in standby power use. )

  • It’s good that the manufacturer has made cloud connectivity optional. As a general rule I would never buy an IoT device which requires cloud connectivity to function. (Internet goes down, manufacturer stops supporting, etc.)


Nice post regarding the pros and cons of Shelly devices. :+1: I’m sure others will appreciate this if they’re also looking for similar devices.