Electronic lock system having proximity mobile device

An electronic lock for mounting on a door including an interior side, an exterior side and an edge extending between the interior side and the exterior side, the door defining a bore extending between the interior side and the exterior side and including a side bore extending through the edge, the electronic lock comprising:

• a strike attached to the edge of the door, wherein the strike defines an opening aligned with the side bore;
• a latch assembly including a bolt movable between an extended position and a retracted position, wherein the bolt extends through the opening in the strike in the extended position;
• an interior chassis mounted to the interior side of the door, the interior chassis including at least one circuit board and a manual turnpiece movable to actuate the bolt between the extended position and the retracted position;
• an exterior chassis mounted to the exterior side of the door, the exterior chassis having a locking device including a keyway and being movable to actuate the bolt between the extended position and the retracted position, the exterior chassis including a sensor configured to generate an electrical signal responsive to detecting either:
• (1) the presence of a user within a range of the locking device without any physical contact of the sensor;
• or (2) physical contact with a contact region of the sensor;
• a circular-shaped adapter dimensioned to adapt at least a portion of the exterior chassis for a particular sized opening in the bore in the door, wherein the sensor is electrically connected to the circuit board in the interior chassis using an electrical cable extending through the adapter;
• wherein the circuit board is configured to control movement of the bolt between the extended and retracted positions, wherein the circuit board includes:
• a RFID device configured to wirelessly read an access code from a mobile device;
• a non-transitory computer-readable medium having a valid access code and a computer program code stored thereon;
• a processing unit in communication with the proximity sensor, RFID device, and the computer-readable memory, wherein the processing unit is configured to carry out instructions in accordance with the computer program code, wherein the computer program code, when executed by the processing unit, causes the processing unit to perform operations comprising:
• receiving an electrical signal from the sensor;
• activating the RFID device for a predetermined time period responsive to receiving the electrical signal from the sensor;
• receiving an access code from the RFID device;
• determining whether the access code received from the RFID device is the valid access code;
• determining whether the key fob is on the exterior side of a door by performing RF triangulation with the RFID device;
• and
• initiating the actuation of the bolt to the retracted position responsive to determining the access code is the valid access code and determining that the key fob is on the exterior side of the door.