Methods and apparatus for pet doors

1. A door unit configured to connect to a pet doer security panel holder and respond to a signal from an authorized tag associated with a pet, comprising:

a frame having a hole defined therethrough;

a door disposed over the hole and mounted on the frame, wherein the door opens only away from the security panel holder;

a motor, wherein the motor drives movement of the door;

a security panel interface on the frame, wherein the security panel interface comprises a selectable modular connector adapted to hang the frame on the security panel holder;

a tag sensor disposed on a central part of the door, wherein the tag sensor comprises a directional wireless Bluetooth sensor, comprising:

an interior sensor disposed on a first side of the door;

an exterior sensor disposed on a second side of the door; and

a shield housing, wherein the shield housing shields the interior sensor from signals from a first direction and shields the exterior sensor from signals from a second direction;

a control system responsive to signals from the tag sensor, wherein:

the motor is responsive to signals from the control system; and

the control system causes the motor to open the door when the tag sensor receives the signal from the authorized tag.

2. A door unit according to claim 1 , wherein the security panel interface comprises a grooved structure configured to engage the security panel holder.

3. A door unit according to claim 1 , wherein the door comprises two door panels.

4. A door unit according to claim 3 , wherein each door panel swings between an open position and a closed position.

5. A door unit according to claim 1 , further comprising a clutch system coupled to the motor and responsive to a resistance to the movement of the door, wherein the clutch system at least partially disengages the motor from the door in response to the resistance.

6. A door unit according to claim 1 , wherein the motor is disposed inside the door.

7. A door unit configured to connect to a pet door security panel holder and respond to a signal from an authorized tag associated with a pet, comprising:

a frame having a hole defined therethrough;

a door disposed over the hole and mounted on the frame, wherein the door opens only away from the security panel holder;

a motor, wherein the motor drives movement of the door;

a security panel interface on the frame, wherein the security panel interface comprises a selectable modular connector adapted to hang the frame on the security panel holder;

a tag sensor disposed on the door, wherein the tag sensor comprises a directional wireless Bluetooth sensor, wherein the directional wireless Bluetooth sensor comprises:

an interior sensor disposed on a first side of the door;

an exterior sensor disposed on a second side of the door; and

a shield housing, wherein the shield housing shields the interior sensor from signals from a first direction and shields the exterior sensor from signals from a second direction; and

control system responsive to signals from the tag sensor, wherein:

the motor is responsive to signals from the control system; and

the control system causes the motor to open the door when the tag sensor receives the signal from the authorized tag.

8. A door unit according to claim 7 , wherein the security panel interface comprises a grooved structure configured to engage the security panel holder.

9. A door unit according to claim 7 , wherein the door comprises two door panels.

10. A door unit according to claim 9 , wherein each door panel swings between an open position and a closed position.

11. A door unit according to claim 7 , further comprising a clutch system coupled to the motor and responsive to a resistance to the movement of the door, wherein the clutch system at least partially disengages the motor from the door in response to the resistance.

12. A door unit according to claim 7 , wherein the motor is disposed in the door.

13. A door unit according to claim 7 , wherein the tag sensor is disposed on a central part of the door.

14. A method of operating a door unit configured to connect, to a pet door security panel holder surrounding an opening and respond to a signal from an authorized tag associated with a pet, comprising;

positioning a frame having a hole defined therethrough adjacent opening, wherein the hole is aligned with the opening;

selecting a modular connector from a plurality of modular connectors, wherein the selected modular connector engages the security panel holder;

mounting the selected modular connector on the frame;

hanging the frame on the security panel holder via the selected modular connector;

sensing a signal corresponding to an approach of a tag;

determining whether the sensed signal corresponds to the authorized tag;

determining whether the pet is on a first side of a door or a second side of the door, comprising;

sensing the signal from the direction of the first side of the door;

sensing the signal from the direction of the second side of the door; and

comparing the signals as sensed from the first and second sides of the door; and

opening a door disposed over the hole and mounted on the frame if the sensed signal corresponds to the authorized tag, comprising opening the door away from the security panel holder.

15. A method of operating a door unit according to claim 14 wherein the signal corresponding to the approach of the tag is a Bluetooth signal.

16. A method of operating a door unit according to claim 14 , wherein the door comprises two door panels, and each door panel swings between an open position and a closed position.

17. A method of operating a door unit according to claim 14 , further comprising automatically stopping the door if the door resists movement.