A Truly Smart Home Should Know Who Is In What Room

Actually, we fitted smart wall switches rather than independent light bulbs, but it’s the same difference.

Smart lights are the go-to accessory to kit out a smart home with. We set some up in our house a few years ago, and an obvious thing to do was to make it so all the lights turn themselves off at night, so we aren’t wasting electricity, all night long, if someone forgets to flick the switches before going upstairs to bed.

We achieved this by configuring an automation that sets a ‘Good Night’ scene at 2 AM. It turns off the TV and some other stuff too. It’s neat, useful even. But a time-based schedule is far from an ideal trigger for this. What if someone happens to stay up late? Well, tough luck, everything is still going to unceremoniously turn itself off. The automation is set at 2 AM because all members of the family have clocked out around midnight or 1 AM, and that leaves enough of a buffer to account for the occasions when people stay up for another hour or so. Still, it’s not a foolproof system. The hack also means that when people are — most often — usually in bed before 12, the lights accessories are not automatically turned off for another two hours, wasting electricity for no reason.

It also doesn’t help with all the times during normal waking hours when people turn lights on and then leave the room. If you want to solve for that situation, a fixed time automation is not sufficient. The next tool in the arsenal is motion sensors, setting stuff to turn off when no motion is detected for a while. I’ve attempted to use a couple of motion sensors from different brands, but they are all largely unsatisfactory at the job. They aren’t reliable in general, especially for larger rooms and people might be obscured by sofas or tables; a very common pitfall is that when people relax, like reading a book or watching TV, they tend not to move enough to trigger the sensor. Motion sensors can be successfully deployed in some specific scenarios, but they aren’t general purpose solutions to the task of turning stuff on when people aren’t there anymore.

A few dedicated room occupancy sensors do exist. They typically attach to door frames, and count how many people enter and exit each room. If the count is greater than zero, the room is considered occupied. Unfortunately, these kinds of sensors are cost prohibitive, somewhat ugly, and also imperfect; a missed count of just one person will mean the total is off, requiring manual intervention to reset it. People enter and exit rooms a lot; even something that is 99% accurate will be wrong enough times to be frustratingly annoying.

So, the ‘simple’ task of intelligently automating turning things off in a house remains an open problem to crack. The 2 AM Good Night automation I use at the moment is a crude hack, but works well enough to tease the possibilities of where we could go in the future. I think fully solving room occupancy is the key to doing this and a world of other related fun and useful features.

The promise of a smart home could really come into its own if we could reliably detect exactly who is in what room. If the iPhone knew what room you were in at all times, you could open the Lock Screen and immediately see relevant smart home controls for the lights and accessories in your immediate proximity, as that is odds on what you wanted to change. It would be great to be able to say to your watch ‘turn on the light’, and the virtual assistant actually do exactly what you intended to happen as if you were talking to a real person; turn on the light just in that room where you are and nothing else.

Reducing friction is vital to making smart home stuff feel more useful and less of a gimmick. If the home knew who was in the lounge, it could change to that person’s user profile on the TV automatically. Playback of a podcast on smart speakers could follow someone through the house, as they move from eating dinner in the dining room to relaxing in their room. It’d be really cool if a smart speaker could automatically avoid expletive-filled music when young kids were known to be nearby. Smart thermostats could adjust to the temperature preferences of the person in the room at any moment, and perhaps turn off heating altogether when the system reliably knew everyone had gone to their rooms at bedtime at night. And your wake-up alarm could turn itself off when it observed you walk out of your bedroom the next morning.

I don’t pretend to know how we get there technologically. I figure it would probably involve coordination between some camera-esque sensors dotted around the home and communication with the devices people carry on them, like phones and watches. Maybe Apple could take advantage of Ultra-Wide Band positioning to accurately follow people’s movements throughout a house, with various static nodes like HomePods or Apple TVs or Echo speakers or whatever working in concert to track and triangulate the signals. I hope manufacturers pull on that Thread and see where it takes us (pun intended).