One reason you might want a server is to have more expressive power than "if someone literally enters the room, turn on the lights". You might want to turn on the lights and run the AC a little before you predict people will arrive, for example.
Maybe, but that seems like a lot of work for little gain.
You probably don't actually have that much control over the AC in your rooms unless you have zoned heating and a lot of zones, regardless of how smart your sensors are.
Intent is a very important factor when answering the question "should the lights be on," I don't think you'll be able to predict that. For instance: if movement is detected in the bedroom at 2AM, should the lights come on? The answer is: a very strong maybe.
That's how I feel about Alexa.
As someone who doesn't have a voice for radio, I much prefer being able to interact through dexterity. Besides, I'm very picky when it comes to which specific track of music is to be played (out of various similarly named pieces of music).
* I don't think take-up is quite as big as the tech world currently makes it out to be. People in my circles don't really have that kind of disposable income and are prioritising other purchases first.
So yeah, Alexa is a lot of extra literal work for little gain.
You would be collecting data from many sources in order to predict intent. This is why you need a centralized server.
Please explain, exactly, what other sources you would collect data from and how the central server would process it to determine if I want the lights on in the middle of the night.
IMHO, determining intent in this scenario is impossible without...
1. a mind-reading sensor, or...
2. an explicit user signal, such as a button-press or command.
The only realistic option is a user signal, and most of those options obviate a lot of these prediction ideas.
I think there's a lot less practical value to having a "central server" controlling everything than you seem to assume.
Machine learning navel-gazing is the new "throw a start-up at it", so I'm guessing the answer to this is going to be "if we have enough data..."
The more data, the more smarter. In fact, the only difference between a thermostat and the human mind is the number of datas. This is because the Law of Averages predicts that half of all datas will be relevant.
There are several important caveats to this statement.
> In fact, the only difference between a thermostat and the human mind is the number of datas.
This is an oversimplification that borders on dogma.
> This is because the Law of Averages predicts that half of all datas will be relevant.
An interesting interpretation and application.