TL;DR
Stephen Cass created a unique wooden lockbox that conceals its locking mechanism, requiring a specific magnetic gesture to unlock it. Instead of using a visible keyhole or keypad, this box utilizes SparkFun's Magnetic Imaging Tile, which features an 8×8 array of Hall-effect sensors. These sensors detect the strength and polarity of magnetic fields, allowing the system to recognize a specific pattern traced by a magnet across its surface.