Patent attributes
An apparatus includes an enclosure, a central processing unit, a power source, a first distance measuring device, a first compressible member, and a first housing pin, where the central processing unit is electrically coupled to the power source and the first distance measuring device. A first end of the first compressible member is mechanically coupled to a first end of the first housing pin and a second end of the first compressible member is mechanically coupled to an inner surface of the enclosure. The first distance measuring device positioned at the second end of the first compressible member, where the first distance measuring device is configured to measure a first distance to the first end of the first housing pin. A first key pin of a key structure disposed in the enclosure, where the first key pin is configured to compress the first compressible member the first distance.