Hello everyone,

As proud owners/housemates of two magnificent cats (and objectively speaking, they are stunning!), we've run into a little issue with the younger one: she absolutely refuses to use the litter box after her big brother. Despite many attempts and layout changes (we've tried three litter boxes in different areas), nothing works — she really is a little princess!

So, we had no choice but to assign her a private litter box with restricted access.

I’ve designed an automatic lock that activates when her magnetic pendant passes over a Hall effect sensor.

The system runs on an ESP32 board, integrated into Home Assistant via ESPHome. It uses a 28BYJ-48 stepper motor with its controller and a DC-DC converter for power supply.

I’m also planning to upgrade the system by adding an NFC reader, so I can distinguish between the two cats and prevent “unauthorized access” — like triggering the vacuum cleaner nearby, for ex