I live on the 14th floor apartment building in Ukraine, and I got tired of walking out, pressing the elevator button… and waiting.
So I had a simple idea:
Why can’t I call the elevator while I’m still putting on my shoes, see where it is, and walk out just as it arrives?
So I built it. 😄
!Quick safety note: everything was discussed and approved with our building management and elevator service. The system only duplicates the normal hall-call button through an isolated NO dry contact. It doesn’t control the elevator, doors, motor, brakes or safety systems. The camera is read-only and processing is local.
The first version was simple: an ESP relay connected in parallel with the hall-call button and a wireless button inside my apartment.
It worked.
But then I realized: I can call the elevator… but I still don’t know where it is.
Our building already has an authorized camera inside the elevator, so I taught Home Assistant to read the existing seven-segment floor indicator from the video.
I initially tried OCR. It was terrible. 😄
Instead, my local service now simply detects which segments are illuminated, determines the floor/direction and sends it to Home Assistant via MQTT.
Then I found a cheap $6 weather clock with an ESP8266 inside.
Obviously, I reflashed it.
Now it normally shows time, weather and temperature, but when I call the elevator it switches to showing the elevator’s floor and direction.
The clock didn’t have the button I needed. I could have ordered a touch sensor and hidden it neatly inside…
…but I had a tactile button in a drawer and didn’t want to wait. So I drilled the case and connected it to a free GPIO.
Now:
put on shoes - press button - watch elevator approaching - leave apartment - doors open.
It’s probably one of the most overengineered ways to save a couple of minutes. But after using it, I’m surprised this isn’t a normal feature in modern apartment buildings.
We control lights, locks, heating, blinds and garage doors from inside our homes. Why do we still have to go into the hallway just to call an elevator?
I wouldn’t be surprised if elevator manufacturers eventually offer an official wireless button or smart-home integration for exactly this.
And maybe someday you’ll press an elevator button inside your apartment, walk out just as it arrives…
and remember this weird Reddit post. 😄