With just a few simple buttons, no display to read, and the ability to stop and start songs using RFID tags embedded into 3D printed figures, it’s a perfect interface for tiny humans just ...

The system is built around an ATMega32 microcontroller with a 16×2 LCD display ... emplaced near a door or other RFID reader and left to crack a lock with a 32+62 bit password at 125 kilohertz.