* *card-reader* is an XBus input connected to an RFID card reader.
* *learn* is a simple input connected to a button inside the room.
* *unlock* is a simple output connected to an electric strike plate.
* The door is first *unlocked* by the hotel staff using a special *card* (9999999999).
* The user can then reprogram their lock by holding the *learn* button and scanning their *card*.

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* When the user scans their *card* again after reprogramming, the door should be *unlocked*.
* Any *card* other than the user's *card* or the hotel staff *card* should not *unlock* the door.
* To *unlock* the door, the *unlock* signal should be held high for 6 time units.