A video post shows a robot vacuum parked inside a kitchen island behind a flap door. The builder writes that the door opens according to the cleaning schedule and closes when cleaning is done, using a 12V linear actuator, an LED strip that shows the actuator and robot status, and an ESP32-C3 microcontroller managed in Home Assistant.

The most-upvoted reply jokes about meeting the door with an ankle at 3 a.m.; others warn that it closes fast enough to worry about children, toes and pets. The builder replies that an infrared sensor reopens the door if anything is in its path, that it sends a notification if the flap stays open too long, and that an emergency stop can cut power to the actuator. Others asked for a write-up. About 2,500 upvotes in a 386,000-member community.