I am a noob to home automation but I have a few Kasa light switches that I like. The Kasa switches connect via wifi and Google is able to interact with them. I am also interested in some smartblinds (maybe Smartwings) and I notice they REQUIRE a hub. I understand they are Zigbee over wifi. Why do some devices require a hub and others don’t?
WiFi devices use the Internet Protocol and can communicate with online services and apps over normal computer networks.
Zigbee, Zwave, etc use a completely different protocol that can’t interact with the Internet directly. These protocols are optimized for low power use and for interacting with other home automation devices over their own short range wireless channels.
These devices can technically communicate with each other directly, without a hub, but then you must use a remote control device. For example, there are ways to pair certain Zigbee switches to directly control a Zigbee lightbulb.
The hub is used to bridge the HA wireless protocol with the Internet Protocol. This way your phone (which doesn’t have a Zigbee/Zwave radio) can connect to the hub and control everything.
Wifi is fine for some things, but it’s power hungry, it requires an IP address for each device, and is subject to interference from other wifi devices. If you want to block all of the devices from accessing the internet, it adds some extra complexity. If you have a battery powered wifi device, it will power itself off until activated, then have to connect to your wireless network (DHCP, etc) before it can transmit, which takes a second or three.
ZigBee, ZWave, and BLE are low power protocols, and are fairly statically configured. They use less power and can have much better battery life on much smaller batteries. When activated, they connect back to their respective networks immediately, so things like smart buttons and motion sensors are very fast.
In addition to the other comments here, if you are planning on adding lots of smart devices to your home consider zigbee.
Wifi = great! But most cheap home routers start crapping out when lots of devices connect. Generally if you are going to use lots of wifi devices get a decent mesh wireless system like Unifi (**other good wifi mesh systems are on the market, this is just my experience) and you’ll be good. So Wifi ok to start out, but expect problems as you grow if you are using your ISP provided router.
Wifi also means the manufacturer of your device can get it to “phone home” which has various security and privacy implications.
Wifi also means you are typically dependant on someone elses cloud and as we have seen with Chamberlain MyQ, they can degrade your device to force you to subscribe to services. Manufacturers can also go out of business and again you are sort of screwed.
Because Zigbee (Matter, but I’d personally leave that one alone for a while), Z-Wave use a hub, even if the manufacturer goes out of business there are still methods to control these devices.
You have to be careful not to confuse Matter and Thread.
Matter is a protocol which works over multiple mediums including WiFi and Thread, but theoretically over any protocol (Matter over two cans and string is a possibility I guess 🤣).
Thread is meant to be the spiritual successor to Zigbee. Time will tell as to whether it comes good on its promise.
Just stay away from any “new shiny tech”, stick with the mature, old, boring stuff.
Actually Matter works really well. Specifically if you have a HomeKit-centric set up.
I’ve not had a chance to play with Thread yet.
Because Zigbee, Zwave, BLE, and various proprietary RF data transmission schemes aren’t WiFi.
Zigbee doesn’t use Wi-Fi.
Generally you will want to use a hub for your home automation. Most will use z-wave, zigbee and Wi-Fi. Some will also do Matter.
Using a smart home hub, you can have automation routines that tie all devices on various protocols together. The popular smart home hubs are Hubitat and Home Assistant.
No mater what you decide, home automation is not cheap. And, remember, you get what you pay for. Remember that. Lot of Wi-Fi devices require internet, and they communicate a lot with their manufacturers’ servers.