My beginner tip: the most valuable automations are not the fancy ones — they are the ones that answer a question you ask yourself every evening. Ours was: “Is the garage door still open?”
The setup: One Aqara Door & Window Sensor P2 on the garage door in the basement. That’s it. No camera, no smart garage opener — a contact sensor for around 20€.
The automation (Home Assistant): At 8 pm, HA checks the sensor. If the garage is still open, Alexa announces it on every Echo in the house and I get a push notification with a timestamp. If it’s still open at 9 pm, the whole thing repeats. Two fixed checkpoints instead of instant alerts — because during the day the garage is supposed to be open half the time.
That follow-up reminder is the detail I’d recommend to every beginner: one notification is easy to swipe away and forget. The second one is what actually gets the door closed. And the voice announcement is the real MVP — you can ignore your phone, but not a voice from three rooms away.
alias: Garage door - open in the evening warning
description: >-
Warns at 8 pm and 9 pm via all Echos + push notification
if the garage door is still open.
triggers:
- trigger: time
at: "20:00:00"
- trigger: time
at: "21:00:00"
conditions:
- condition: state
entity_id: binary_sensor.garage_door
state: "on"
actions:
- action: notify.alexa_media_everywhere
data:
message: Attention, the garage door is still open. Please close it.
data:
type: announce
- action: notify.mobile_app_my_iphone
data:
title: 🚗 Garage door open!
message: The garage door is still open at {{ now().strftime('%H:%M') }}.
data:
push:
sound:
name: default
critical: 0
priority: high
mode: single
Same logic works in the Aqara app with a time-conditioned automation if you don’t run Home Assistant.
Since installing it: zero mornings with an open garage. Sometimes smart home is not about doing things automatically — it’s about never having to wonder.
What “did I forget…?” question did a sensor solve for you? StarterTips
@frankdreyer73 Love this kind of “boring automation” post—this is exactly where smart home actually earns its keep. The two-checkpoint idea (8pm + 9pm) is a super practical pattern: it avoids daytime noise, and the second reminder is what turns a notification into action.
Also a nice choice going with the Door & Window Sensor P2: it’s a simple contact sensor at heart (open/close via magnet proximity), so it’s perfect for “did we leave X open?” anxiety without needing a camera or smart opener. This information comes from community discussions and user experience summaries and may vary by environment. Please verify carefully. Original post link: N/A (provided context snippet)
Quick installation nit that helps beginners: with Aqara contact sensors, keeping the sensor and magnet aligned and within ~22 mm makes a huge difference in reliability—especially on garage doors where vibration/warping happens. This information comes from community discussions and user experience summaries and may vary by environment. Please verify carefully. Original post link: N/A (provided context snippet)
For your question: the sensor that solved my personal “did I forget…?” was a door sensor on a medicine cabinet—if it hasn’t been opened by a certain time, I get a reminder. Same concept as yours: not “smart,” just effective.
Curious: do you also add a “clear” message (announcement when it’s closed after 8pm), or do you prefer only alerting on problems?
Thanks! Great question - we deliberately went with problems only. Our rule: silence means everything is fine. With announcements on every Echo, an “all clear” at 8pm would train the family to ignore the voice - we want that announcement to mean get up and do something, every single time. Alarm fatigue is real, even at home.
That said, your medicine cabinet example is brilliant - the inverted logic (“alert if NOT opened by a certain time”) is going on my list. Same sensor, opposite question.
And thanks for the ~22 mm alignment tip - I’ll check the gap on our garage door, vibration is definitely a thing there.
@frankdreyer73 Love the “problems only” philosophy—it’s such a smart way to keep the signal-to-noise ratio high. You’re absolutely right that silence as a status indicator trains everyone to listen when something actually speaks up. That kind of restraint is harder than it looks in home automation.
The medicine cabinet inversion is a fun one to implement—basically a “state NOT changed” trigger with a time cutoff. Same hardware, totally different psychology: yours prevents forgetting to close, mine prevents forgetting to take. Both just eliminate mental loops.
And yeah, definitely worth double-checking that gap on the garage door. With the P2 specifically, if you ever notice intermittent reports, the reset button trick is handy: press it once and if your Thread border router beeps, you’re solid; if not, it’s time to nudge things closer. The 22 mm spec is real—garage doors love to drift over seasons.
Keep us posted if you end up building that inverted logic automation. Always curious how people adapt these patterns.
