There are two kinds of smart switches that can turn on with motion.
The old style are standalone devices that have a motion sensor built into them. They don’t talk to anything else. You can’t control them with Alexa or an app. you can’t schedule them for certain times of day. A few of them will have a light sensor so they won’t turn on if the room is already bright, but again that’s built into the switch and it’s not controllable.
So these kinds of smart switches just work every time. You walk past the switch, the light turns on (again, with the possible exception of a test for brightness.) these are normally called “occupancy sensor light switches“ in the UK. They should cost between 15 € and 25 €. Widely available from many different manufacturers, here’s just a typical one:
The other kind of smart switches are “networked switches.“ Those will probably work with Alexa, probably work with an app, and let you set different kinds of conditions. That’s where the sensor will typically be a separate device from the light switch. Those cost more, in part because you now have two devices, but also just because they are, well, smarter.
So it just comes down to the details of what you want to do.
I have both kinds in my own home. Anywhere I want voice control, I have a networked smart switch. But, for example, in the laundry area I just have an occupancy switch. Because I know that I want that light to turn on every time someone walks into that area. I don’t need voice control for either on or off.
Similarly, we have a utility closet with an occupancy switch. You open the door, the light comes on. After you close the door it eventually goes off again.
So it just comes down to the details of what you want.
Even in the networked switches, there are some less expensive options than the ones you discussed. But again, they have different features and it depends on exactly what you’re trying to do.
By the way, this particular forum is for people who are using the Samsung SmartThings™ Home automation platform. It’s not a general home automation discussion forum. So all of the questions and answers are assumed to be in the context of that particular system. Just so we’re all talking about the same thing.
For example, people using the Samsung platform who want to use Zigbee devices will likely get a SmartThings/WASH hub, or already have one. The cost is spread across all of the devices that they intend to use.
People who are not using that platform might just use an echo device with a built-in Zigbee hub in order to save money. Or look at one of the inexpensive systems like IKEA, Aqara, or Tuya. But that would be a discussion for a different forum, probably the Reddit home automation sub forum, which covers all platforms:
Only some Echo models have a Zigbee hub inside. As far as I know, none of the dot models do, and specifically the fourth generation Echo Dot does not.
Note that the “echo fourth generation“ is a different device than the “echo dot fourth generation,“ which may be where the confusion was.
The following Echo devices have built-in smart home hubs that seamlessly connect and control Zigbee smart devices:
Echo 4th Generation
Echo Show 10 (all models except 1stGeneration)
Zigbee hub yes:
Zigbee hub no:
Both are good devices, but the larger one does have some additional features, including the Zigbee hub inside.
Yes, that’s why I said “typically.“ There are a few networked switch models which have a built-in sensor. GE has some in the US. These are more common in North America than in Europe/UK, though, because of the larger physical size of the switches.
If you plan to motion- automate only one light.
I would go with no-brand lightbulbs with motion activation embedded. It was possible to find them cheaper than 15$.
But at some point, you will like the home automation and willing to grow your device list. and then you will waste a lot of money because you haven’t planned ahead.
you will trash most of the cheap lights because you want better quality and more features.
You will want a more flexible automation engine.
You will want to add more devices from various brands to your home.
the list of officially supported brands and devices is smaller.
community drivers. I can order a pack of 5 motion sensors from Aliexpress for $60 (before inflation)
not a part of the mobile OS, when you are watching TV you can’t just swipe down and turn off the light - you have to unlock the phone in the Alexa app and wait until it’s loaded, then switch to the devices menu. There is no smartness in the device list, no “recent” list, or even search you have to find that light
I believe Google Assistant is way better at intent recognition and overall as a personal assistant than Alexa
I got iOS Homekit working, so my wife can control the smartphone from her phone as well
If you don’t want smart control ( routines, app control etc)
You can buy an IKEA motion sensor and bulb, and pair then directly together using touchlink, no hub required. They sometimes sell them in kits. You can always add a hub later ( smartthings, IKEA, Alexa etc)
We find that one in a hallway or bathroom lights things up plenty at night. And I think there are 2 brightness settings, we have it on the lowest. My only gripe is the cats set them off walking around at night.