The report from the condo up north was simple: Alexa could close the shades, set the air conditioning, run the scenes — but ask her to turn off a light, any light, and you got nothing. All twenty lights in the place, invisible.
A default that never worked
The root cause was a classic silent failure. Home Assistant’s cloud service has a default rule that’s supposed to expose whole categories of devices to Alexa — lights being the most obvious category on the list. On this box, that default had simply never worked. Anything with an explicit per-device expose flag synced fine, which is exactly why the shades and ACs worked: they’d each been flagged individually at some point. The lights were all riding the default. The default was a ghost. Twenty devices, all technically “exposed,” none of them actually leaving the building.
The same thing had bitten the shades a month earlier, which is the embarrassing part — I’d already met this bug, fixed its symptoms, and not generalized the lesson. This time I flagged every light explicitly, forced a full re-sync to Amazon, and all twenty appeared in the Alexa app immediately.
Voice-only for Oma and Opa
Then, since I was in there, the real project: my in-laws — Oma and Opa — were about to have the place to themselves, and they should be able to run it entirely by voice. No app, no dashboard, no calling me.
That turned into a full speakability pass. Every device with an ampersand in its name got an “and” alias, because Alexa can’t hear punctuation. Every room’s lights got grouped so one phrase moves the whole room. Thirty-seven devices got re-aliased into every phrasing two people might plausibly try. Their goodnight scene got a one-word alias — just “Bedtime” — and the house-wide scripts got renamed so their “goodnight” can’t accidentally shut down the entire building.
A sunset, not a blackout
The scenes are my favorite part of the whole job. “Oma and Opa Goodnight”: the bedroom and bathroom lights fade out slowly over two minutes — not a blackout, a sunset — the shades close, the AC settles to 19°, and the bedroom speaker starts a white-noise track at gentle volume. “Good Morning” reverses it: music off first so the room goes quiet instantly, temperature back up, shades open, lights on.
Always say degrees
One genuine Alexa absurdity survived all tuning: temperature commands only work if you end the sentence with the word “degrees.” “Set the AC to 21 degrees” works. “Set the AC to 21” gets you “I don’t know what went wrong,” which — same, Alexa. That rule went on the printed one-page command card I left on the counter, next to the phrase list.
The automation project I’m happiest with this year wasn’t adding anything. It was making what already existed answerable to two people who shouldn’t need to know any of it exists.