Most IoT hardware wants to tell you something. Ours is deliberately mute.
The device in the room
There is no speaker, no screen, no status light that means anything to the person living there, no buzzer, no voice announcing a state, and no button to press. It plugs into a wall socket, listens to the WiFi field already in the room, and sends a small state packet upstream. It makes no sound and asks for nothing. The person being observed does not get an app, an account, a password, a wearable to charge, or a notification to dismiss.
That asymmetry is the product. Every feature we could avoid asking of an 80-year-old, we avoided. A device that announces itself in a parent's home has already changed the relationship, regardless of how accurate its sensor is.
Where the judgement happens
The box only sends a state. Every interpretation happens on the screen, in front of a person who has context the sensor does not have: whether she said she would be out, whether it is a holiday, whether the grandchildren visited. We say "this room changed", never "she got up". The unit of the product is a room, not a person. That grammar is deliberate — it is much harder to overclaim when the sentence stays about a place.
So there is no LED that turns red, no "all fine" green, no safety score, no push notification, no daily digest email. Each of those would require the product to assert a reason for a change, and the signal contains no reasons. The board is a web page you open when you want to know, at annest.cn/live/, not an app that interrupts you.
The one habit that does change
The person being observed changes nothing. The person watching changes one habit: instead of asking "did you get up today" on every call, you glance at two numbers — how long since the room last changed, and whether the link is alive — when you happen to think of it. The daily phone call stays the right thing; the board just means that call can be about something else. It is not a replacement for a caregiver.
What we keep, and what we refuse
We keep the current interval and a short recent window. We do not build a year-long portrait of someone's habits; a long-term profile would be useful for a score and useless for the one question we answer. The raw radio waveform never leaves the box; upstream is a state plus a timestamp, a few bytes. No camera, no microphone, no footage to leak or subpoena.
We do not measure heart rate or breathing, do not claim to detect falls, and send no alerts of any kind. Not a medical device, no diagnosis, no emergency response — in an emergency, call 120. Distance: about 10 metres in the same room, about 5 metres through one ordinary interior wall; beyond that the board says "no signal", which is also an answer.
Price, once: 499 CNY including the first month of service, then 30 CNY a month. This is the WiFi sensing unit only. The board shows a room, not a verdict about a person. Quiet hardware is not a missing feature list. It is the feature.
