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?
there are hubs/bridges and then there are controllers.
Every smart device requires a controller because the truth is, none of them are smart. At most you get a timer, which, let’s be honest, was available back in the 60s. It’s the controller that does IF/THEN logic, tying multiple devices together
Hubs/Bridges let two different technologies talk to each other. Your router is a wifi hub/ethernet bridge you already bought. So you don’t need any bridges to connect Kasa devices. At least as long as your router can handle the number of devices. Many consumer routers are only given enough CPU/RAM to handle maybe two dozen devices.
So the question you need to ask yourself about Kasa is where is the controller? Who owns that? Who can turn it off? What happens if they do? For most Wifi devices the answer is “in the cloud, owned by the manufacturer, who can turn it off whenever they want and there’s a good chance your switches become dumb switches”.
Zigbee/ZWave needs a bridge, which is often a USB stick on a PC that acts as a controller or is integrated into a dedicated controller. Every $40 zwave radio is good for 232 devices. Zigbee devices vary but the vast majority are good for 100+ and even the most under-specced Hue hub is good for 50 zigbee bulbs.
I use HomeSeer running on a mini PC with a zwave usb radio to control my 80+ devices. if Homeseer goes under, I lose remote control until I set up a VPN server. But all my devices will still follow all their programming, I can add new devices, new rules, and let it continue to run for years if I choose.