A Home Assistant Community member recently shared a hobby project built after moving their mother, who has early-stage dementia, into the family home. The mother had episodes of night wandering: she would get up around 2:00am, get dressed, make her bed and walk around the house. Notes on the mirror and large clocks did not help. The only thing that worked was an adult getting up to guide her back to bed. The poster is clear that this supplements human supervision and that nobody should rely on it as a safety system. We agree, and we are covering it because the design lessons apply to any installed presence setup.
What the system does
It responds in steps rather than sounding an alarm for every bathroom trip.
- Evening guide light: after sunset, an under-bed LED strip comes on dim and warm (25%) when she is moving around the bedroom and not yet in bed.
- Night mode: once her bed has been occupied for 20 minutes, she counts as settled. Between 9 PM and 6:30 AM, if no adult is out of bed, the system arms. It stays armed past 6:30 AM if both adults are still in bed.
- Step one: about 15 seconds after she leaves the bed, the light comes on and a calm recorded voice in the hall says her name and suggests going back to bed, up to three times. The poster used a text-to-speech voice because a familiar voice coming from a speaker might be more confusing.
- Step two: after 5 minutes out of bed, or shortly after she is sensed in the family room, a normal phone notice goes out and a similar recording plays there.
- Real alarms: iOS Critical Alerts repeating every 5 minutes if she has been out of bed 20 minutes, enters the laundry room (the basement stairs are there), or is out of bed with no sighting anywhere for 20 minutes, the possible-fall case.
The hardware includes ESPHome-based bed presence sensors, Aqara and ThirdReality motion sensors, Sonos speakers and a Govee LED strip. The poster says AI tools were used to write and test most of the automations. By their account, after a couple of months and some tuning, manual redirection dropped from almost nightly to about three times.
Lessons worth borrowing
- Bathroom trips are the hard part. A motion sensor drops back to off after about 30 seconds of stillness, so “she’s in the bathroom” needs a hold or delay.
- Unavailable is not empty. Bed sensors went unavailable during a network or mesh update and triggered false critical alerts. Trigger on a real occupied-to-empty change, and decide deliberately whether unavailable means alert or ignore.
- Test every alert tier on every phone. iOS Critical Alerts need explicit permission.
- Plan for an internet outage. Lights and local audio kept working, but phone pushes did not. A local fallback, such as a speaker that sounds the critical alert, is still on the poster’s to-do list.
- Presence sensors cannot tell who is in the room. Any motion resets the no-sighting timer, so a caregiver’s movement can hide a problem. A fan in the family room also made a presence sensor read occupied and could mask a fall, so the system turns it off when arming.
- Audit against a written spec. The poster wrote the spec in plain language, had one AI agent build the automations and another review them, and found real differences between spec and live configuration.
What it means for installed systems
If you already run Home Assistant with bed and room presence sensors, nothing here needs special hardware. The sensors are ordinary ones, and the logic lives in automations. Before copying the approach, check how your sensors behave during mesh or firmware updates, and whether a Zigbee or Wi-Fi sensor drop would raise a false alarm at 3am. Working Zigbee sensors do not need replacing for this; keep them until they die. The step that matters most is the local fallback: a phone-only alert chain fails when the internet does, so put a speaker or siren on the local network in the escalation path.
This is a family’s hobby project, not a certified monitoring product. Treat it as a way to reduce nights of broken sleep, keep a human in the loop, and talk to a clinician or care provider about real safety needs.