Electronic access control device

• US 7,295,100 B2
• Filed: 10/20/2005
• Issued: 11/13/2007
• Est. Priority Date: 11/15/1994
• Status: Expired due to Fees

• Current Assignee: O.S. Security LLC (Acacia Research Corporation)
• Original Assignee: Micro Enhanced Technology Incorporated
• Inventors: Denison, William D., Silvers, Bradley S., Brownfield, Lawrence C.
• Primary Examiner(s): ZIMMERMAN, BRIAN A
• Application Number:
  US11/254,263
• Publication Number:
  US 20060038657A1
• Time in Patent Office: 754 Days
• Field of Search: 340/5.54, 340/5.7, 340/5.73
• US Class Current: 340/5.73
• CPC Class Codes: B60R 25/102 a signal being sent to a remote location, e.g. a radio signal being transmitted to a police station, a security company or the owner
• CPC Class Codes: B62H 5/20 indicating unauthorised use, e.g. acting on signalling devices alarm locks in general E05B45/00, e.g. alarm cable or chain lock E05B45/005
• CPC Class Codes: G07C 2009/00793 by Hertzian waves
• CPC Class Codes: G07C 9/00182 operated with unidirectional data transmission between data carrier and locks
• CPC Class Codes: G07C 9/00571 operated by interacting with a central unit
• CPC Class Codes: G07C 9/0069 actuated in a predetermined sequence
• CPC Class Codes: G07C 9/00896 specially adapted for particular uses
• CPC Class Codes: G07C 9/00912 for safes, strong-rooms, vaults or the like
• CPC Class Codes: G07C 9/33 by means of a password
• CPC Class Codes: G07F 7/1008 Active credit-cards provided with means to personalise their use, e.g. with PIN-introduction/comparison system
• CPC Class Codes: G07F 7/1025 Identification of user by a PIN code
• CPC Class Codes: H04Q 1/00 Details of selecting apparatus or arrangements
• CPC Class Codes: Y10T 70/7006 Predetermined time interval controlled
• CPC Class Codes: Y10T 70/7113 Projected and retracted electrically

Abstract

An electronic lock utilizes two microprocessors remote from each other for enhanced security. The first microprocessor is disposed close to an input device such as a keypad, and the second microprocessor is disposed close to the lock mechanism and well protected from external access. The first microprocessor transmits a communication code to the second microprocessor when it receives via the input device an access code that matches a preset access code. The second microprocessor opens the lock if the transmitted communication code matches a preset communication code. The dual-microprocessor arrangement is advantageously used in a voice controlled access control system and in a motorcycle ignition control system. The present invention further provides an electronic access control system which has a master electronic key having a preset number of access, and an electronic alarm system for a bicycle that has a remote control mounted in the helmet of the rider.

Claims

1. An apparatus comprising:

a non-volatile memory containing a stored access code;

a circuit comprising two processors wherein at least one of the processors is shielded from external access;

a portion of the circuitry generating a wake-up signal in response to pressing a key on a keypad;

at least one of the processors being woke-up in response to the wake-up signal and receiving an input code;

at least one of the processors being woke-up and comparing the input code with the stored access code;

at least one of the processor generating a signal to activate a lock actuator if the input code matches the stored access code;

at least a portion of the circuitry comprising a low battery detection circuit that is enabled by one of the processors in an operation mode and disabled in a sleep mode, the low battery detection circuit measuring a voltage of a battery in the operation mode; and

,

wherein at least one of the processors enters a sleep mode wherein the processor operates at a lower power consumption rate than when the processor is awake.

2. The apparatus of claim 1, wherein the keypad includes a program key, and wherein at least one microprocessor is programmed to enter a code programming sequence in response to pressing the program key, receive a first input code from the keypad, compare the first input code with the stored code in the memory, receive an additional code from the keypad if the first input code matches the stored code, and store the additional code in the memory.

3. The apparatus of claim 2 wherein the stored access code is non-reprogrammable via the keypad.

4. The apparatus of claim 3 wherein the circuit generating a wake-up signal is in response to pressing a first key on said keypad used in entering said input code comprising the first key and at least one subsequent keypad entry.

5. The apparatus of claim 4 further comprising a lock actuator comprising a solenoid control circuit for energizing a solenoid, the solenoid control circuit being controlled by the microprocessor and being enabled when the microprocessor is in the operation mode, the solenoid control circuit having first and second energized states controlled by a timer to energize the solenoid in the first energized state for a pre-selected first time interval at a first power level to move a plunger of the solenoid into a retracted position, and subsequently to energize the solenoid in the second energized state at a second power level to maintain the plunger in the retracted position for a second pre-selected time interval, the second power level being non-zero and lower than the first power level.

6. The apparatus of claim 5, further comprising a communication port connected to the control circuit for sending data to the control circuit for writing into the non-volatile memory to form a stored code.

7. The apparatus of claim 6, further comprising a communication port connected to the control circuit, and wherein a processor is programmed to receive a read signal through the communication port and in response to the read signal to transmit a stored code through the communication port.

8. The apparatus of claim 1 wherein a stored access code is non-reprogrammable via the keypad.

9. The apparatus of claim 1 wherein the stored access code is disabled.

10. The apparatus of claim 1, further comprising a communication port connected to the control circuit for sending data to the control circuit for writing into the non-volatile memory to form a stored code.

11. The apparatus of claim 1, further comprising a communication port connected to the control circuit, and wherein a processor is programmed to receive a read signal through the communication port and in response to the read signal to transmit a stored code through the communication port.

12. The apparatus of claim 1 further comprising a lock actuator comprising a solenoid control circuit for energizing a solenoid, the solenoid control circuit being controlled by the microprocessor and being enabled when the microprocessor is in the operation mode, the solenoid control circuit having first and second energized states controlled by a timer to energize the solenoid in the first energized state for a pre-selected first time interval at a first power level to move a plunger of the solenoid into a retracted position, and subsequently to energize the solenoid in the second energized state at a second power level to maintain the plunger in the retracted position for a second pre-selected time interval, the second power level being non-zero and lower than the first power level.

13. The apparatus of claim 1 wherein a memory contains a limit value and the processor generates a signal to activate a lock actuator in response to the limit value.

14. The apparatus of claim 1, further comprising a processor remote to the access control device configured to communicate a limit value to the access control device through a communication port.

15. The apparatus of claim 1 wherein the circuit generating a wake-up signal is in response to pressing a first key on said keypad used in entering said input code comprising the first key and at least one subsequent keypad entry.

16. An apparatus comprising:

a non-volatile memory containing a stored access code;

a circuit comprising two processors wherein at least one of the processors is shielded from external access;

at least a portion of the circuit generating a wake-up signal in response to pressing a key on a keypad;

at least one of the processors being woke-up in response to the wake-up signal and receiving an input code;

at least one of the processors being woke-up and comparing the input code with the stored access code;

at least one of the processors generating a signal to activate a solenoid if the input code matches the stored access code;

at least a portion of the circuit comprising a solenoid control circuit for energizing a solenoid, the solenoid control circuit being controlled by at least one of the processors and being enabled when the processor is in an operation mode, the solenoid control circuit having first and second energized states controlled by a timer to energize the solenoid in the first energized state for a pre-selected first time interval at a first power level to move a plunger of the solenoid into a retracted position, and subsequently to energize the solenoid in the second energized state at a second power level to maintain the plunger in the retracted position for a second pre-selected time interval, the second power level being non-zero and lower than the first power level; and

,

wherein at least one of the processors enters a sleep mode wherein processor operates at a lower power consumption rate than when the processor is awake.

17. The apparatus of claim 16, wherein the keypad includes a program key, and wherein a microprocessor is programmed to enter a code programming sequence in response to pressing the program key, receive a first input code from the keypad, compare the first input code with the stored code in the memory, receive an additional code from the keypad if the first input code matches the stored code, and store the additional code in the memory.

18. The apparatus of claim 16 wherein a stored access code is non-reprogrammable via the keypad.

19. The apparatus of claim 16 wherein the stored access code is disabled.

20. The apparatus of claim 16, further comprising a communication port connected to the control circuit for sending data to the control circuit for writing into the non-volatile memory to form a stored code.

21. The apparatus of claim 16, further comprising a communication port connected to the control circuit, and wherein a processor is programmed to receive a read signal through the communication port and in response to the read signal to transmit a stored code through the communication port.

22. The apparatus of claim 16, wherein the circuit generating a wake-up signal is in response to pressing a first key on said keypad used in entering said input code comprising the first key and at least one subsequent keypad entry.

23. An apparatus comprising:

a non-volatile memory containing a stored access code;

a control circuit comprising at least one processor wherein at least a portion of the circuit generates a wake-up signal in response to pressing a key on a keypad;

at least one processor being woke-up in response to the wake-up signal and enters an operation mode and receives an input code;

at least one processor being woke-up and comparing the input code with the stored access code;

at least one processor generates a signal to activate a solenoid if the input code matches the stored access code;

at least a portion of the circuit comprising a solenoid control circuit for energizing a solenoid, the solenoid control circuit being controlled by at least one processor and being enabled when the processor is in the operation mode, the solenoid control circuit having first and second energized states to energize the solenoid in the first energized state for a first interval at a first power level to move a plunger of the solenoid into a retracted position, and subsequently to energize the solenoid in the second energized state at a second power level to maintain the plunger in the retracted position, the second power level being non-zero and lower than the first power level;

the control circuit further comprising a low-battery detection circuit that is enabled by the microprocessor in the operation mode for measuring a voltage of the battery and disabled when the microprocessor is in the sleep mode; and

,

wherein at least one processor enters a sleep mode wherein said processor operates at a lower power consumption rate than when the processor is awake.

24. The apparatus of claim 23, further comprising a communication port connected to the control circuit for sending data to the control circuit for writing into the non-volatile memory to form the stored code.

25. The apparatus of claim 23, further comprising a communication port connected to the control circuit, and wherein a processor is programmed to receive a read signal through the communication port and in response to the read signal to transmit the stored code through the communication port.

26. The apparatus of claim 23 wherein the keypad includes a program key, and wherein a one of the processors is programmed to enter a code programming sequence in response to pressing the program key, receive a first input code from the keypad, compare the first input code with a stored code in the memory, receive an additional code from the keypad if the first input code matches the stored code, and store the additional code in the memory.

27. The apparatus of claim 23, the control circuit comprising at least two processors.

28. The apparatus of claim 27 wherein at least one processor is shielded from external access.

29. The apparatus of claim 23 wherein the stored access code is non-reprogrammable.

30. A battery-powered electronic access control device comprising:

a keypad having a plurality of keys and a program key mounted thereon;

at least one microprocessor-based control circuit comprising a microprocessor comprising a memory storing a code, the microprocessor being programmed to enter a sleep-mode to conserve battery power between operations and to awaken from a sleep mode upon pressing a key on the keypad used exclusively to enter a code programming operation;

the microprocessor-based control circuit operatively connected to the keypad for receiving user inputs entered through pressing the keys of the keypad, the microprocessor being configured to enter a code programming operation in response to pressing of the program key, receive an input key code through the keypad in response to detecting the pressing of the program key, and store the input key code in the memory as the access code for the access control device;

the microprocessor-based control circuit further comprising a low-battery detection circuit that is enabled by the microprocessor in the operation mode for measuring a voltage of the battery and disabled when the microprocessor is in the sleep mode.

31. The electronic access control device of claim 30 wherein a stored access code is non-reprogrammable via the keypad.

32. The electronic access control device of claim 30 wherein a stored access code is disabled.

33. The electronic access control device of claim 30 wherein the control circuit comprises at least two processors.

34. The electronic access control device of claim 33 wherein at least one processor is shielded from external access.

35. The electronic access control device of claim 30 further comprising a lock actuator comprising a solenoid control circuit for energizing a solenoid, the solenoid control circuit being controlled by the microprocessor and being enabled when the microprocessor is in the operation mode, the solenoid control circuit having first and second energized states controlled by a timer to energize the solenoid in the first energized state for a pre-selected first time interval at a first power level to move a plunger of the solenoid into a retracted position, and subsequently to energize the solenoid in the second energized state at a second power level to maintain the plunger in the retracted position for a second pre-selected time interval, the second power level being non-zero and lower than the first power level.

36. The access control device of claim 30 wherein a memory contains a limit value and the processor generates a signal to activate a lock actuator in response to the limit value.

37. The access control device of claim 30, further comprising a processor remote to the access control device configured to communicate a limit value to the access control device through a communication port.

38. The access control device of claim 30 wherein the circuit generating a wake-up signal is in response to pressing a first key on said keypad used in entering said input code comprising the first key and at least one subsequent keypad entry.

39. The electronic access control device of claim 30, further comprising a communication port connected to the control circuit for sending data to the control circuit for writing into the non-volatile memory to form a stored code.

40. The electronic access control device of claim 30, further comprising a communication port connected to the control circuit, and wherein a processor is programmed to receive a read signal through the communication port and in response to the read signal to transmit a stored code through the communication port.

41. The electronic access control device of claim 38 wherein a stored access code is non-reprogrammable via the keypad.

42. The electronic access control device of claim 41 wherein a stored access code is disabled.

43. The electronic access control device of claim 30, further comprising an audio alarm and a motion sensor.

44. A battery-powered electronic access control device comprising:

a keypad having a plurality of keys and a program key mounted thereon;

at least one microprocessor-based control circuit comprising a microprocessor comprising a memory storing a code, the microprocessor being programmed to enter a sleep-mode to conserve battery power between operations and to awaken from a sleep mode upon pressing a key on the keypad used exclusively to enter a code programming operation;

the microprocessor-based control circuit operatively connected to the keypad for receiving user inputs entered through pressing the keys of the keypad, the microprocessor being configured to enter a code programming operation in response to pressing of the program key, receive an input key code through the keypad in response to detecting the pressing of the program key, and store the input key code in the memory as the access code for the access control device; and

,

a lock actuator comprising a solenoid control circuit for energizing a solenoid, the solenoid control circuit being controlled by the microprocessor and being enabled when the microprocessor is in the operation mode, the solenoid control circuit having first and second energized states controlled by a timer to energize the solenoid in the first energized state for a pre-selected first time interval at a first power level to move a plunger of the solenoid into a retracted position, and subsequently to energize the solenoid in the second energized state at a second power level to maintain the plunger in the retracted position for a second pre-selected time interval, the second power level being non-zero and lower than the first power level.

45. The electronic access control device of claim 44 wherein a stored access code is non-reprogrammable via the keypad.

46. The electronic access control device of claim 44 wherein a stored access code is disabled.

47. The electronic access control device of claim 44 wherein the control circuit comprises at least two processors.

48. The electronic access control device of claim 47 wherein at least one processor is shielded from external access.

49. The electronic access control device of claim 48 wherein the circuit generating a wake-up signal is in response to pressing a first key on said keypad used in entering said input code comprising the first key and at least one subsequent keypad entry.

50. The electronic access control device of claim 44, further comprising a communication port connected to the control circuit for sending data to the control circuit for writing into the non-volatile memory to form a stored code.

51. The electronic access control device of claim 44, further comprising a communication port connected to the control circuit, and wherein a processor is programmed to receive a read signal through the communication port and in response to the read signal to transmit a stored code through the communication port.

52. A battery-powered electronic access control device comprising:

a keypad having a plurality of keys and a program key mounted thereon;

at least one microprocessor-based control circuit comprising a microprocessor comprising a memory storing a code, the microprocessor being programmed to enter a sleep-mode to conserve battery power between operations and to awaken from a sleep mode upon pressing a key on the keypad used exclusively to enter a code programming operation;

the microprocessor-based control circuit operatively connected to the keypad for receiving user inputs entered through pressing the keys of the keypad, the microprocessor being configured to enter a code programming operation in response to pressing of the program key, receive an input key code through the keypad in response to detecting the pressing of the program key, and store the input key code in the memory as the access code for the access control device;

the microprocessor-based control circuit further comprising a low-battery detection circuit that is enabled by the microprocessor in the operation mode for measuring a voltage of the battery and disabled when the microprocessor is in the sleep mode;

wherein the keypad includes the program key connected to one of the interrupt inputs of the microprocessor, and wherein the microprocessor is programmed to enter a code programming sequence in response to a pressing of the program key, receive a first input code from the keypad, compare the first input code with the stored code in the memory, receive an additional code from the keypad if the first input code matches the stored code, and store the additional code in the memory.

53. The access control device of claim 52 wherein the circuit generating a wake-up signal is in response to pressing a first key on said keypad used in entering said input code comprising the first key and at least one subsequent keypad entry.

54. The electronic access control device of claim 53 wherein a stored access code is non-reprogrammable via the keypad.

55. The electronic access control device of claim 53 wherein a stored access code is disabled.

56. The electronic access control device of claim 53 wherein the control circuit comprises at least two processors.

57. The electronic access control device of claim 56 wherein at least one processor is shielded from external access.

58. A battery-powered electronic access control device comprising:

a keypad having a plurality of keys and a program key mounted thereon;

at least one microprocessor-based control circuit comprising a microprocessor comprising a memory storing a code, the microprocessor being programmed to enter a sleep-mode to conserve battery power between operations and to awaken from a sleep mode upon pressing a key on the keypad used exclusively to enter a code programming operation;

the microprocessor-based control circuit operatively connected to the keypad for receiving user inputs entered through pressing the keys of the keypad, the microprocessor being configured to enter a code programming operation in response to pressing of the program key, receive an input key code through the keypad in response to detecting the pressing of the program key, and store the input key code in the memory as the access code for the access control device;

the microprocessor-based control circuit further comprising a low-battery detection circuit that is enabled by the microprocessor in the operation mode for measuring a voltage of the battery and disabled when the microprocessor is in the sleep mode; and

,

further including a communication port connected to the microprocessor-based control circuit for sending code to the microprocessor-based control circuit for writing into the memory to form the stored code.

59. The electronic access control device of claim 58 wherein a stored access code is non-reprogrammable via the keypad.

60. The electronic access control device of claim 58 wherein a stored access code is disabled.

61. The electronic access control device of claim 58 wherein the control circuit comprises at least two processors.

62. The electronic access control device of claim 61 wherein at least one processor is shielded from external access.

63. The apparatus of claim 58, further comprising a communication port connected to the control circuit, and wherein a processor is programmed to receive a read signal through the communication port and in response to the read signal to transmit a stored code through the communication port.

64. The electronic access control device of claim 58 further comprising a lock actuator comprising a solenoid control circuit for energizing a solenoid, the solenoid control circuit being controlled by the microprocessor and being enabled when the microprocessor is in the operation mode, the solenoid control circuit having first and second energized states controlled by a timer to energize the solenoid in the first energized state for a pre-selected first time interval at a first power level to move a plunger of the solenoid into a retracted position, and subsequently to energize the solenoid in the second energized state at a second power level to maintain the plunger in the retracted position for a second pre-selected time interval, the second power level being non-zero and lower than the first power level.

65. The access control device of claim 58 wherein a memory contains a limit value and the processor generates a signal to activate a lock actuator in response to the limit value.

66. The access control device of claim 58, further comprising a processor remote to the access control device configured to communicate a limit value to the access control device through a communication port.

67. The access control system of claim 58 wherein the circuit generating a wake-up signal is in response to pressing a first key on said keypad used in entering said input code comprising the first key and at least one subsequent keypad entry.

68. A battery-powered electronic access control device comprising:

a keypad having a plurality of keys and a program key mounted thereon;

at least one microprocessor-based control circuit comprising a microprocessor comprising a memory storing a code, the microprocessor being programmed to enter a sleep-mode to conserve battery power between operations and to awaken from a sleep mode upon pressing a key on the keypad used exclusively to enter a code programming operation;

the microprocessor-based control circuit operatively connected to the keypad for receiving user inputs entered through pressing the keys of the keypad, the microprocessor being configured to enter a code programming operation in response to pressing of the program key, receive an input key code through the keypad in response to detecting the pressing of the program key, and store the input key code in the memory as the access code for the access control device;

the microprocessor-based control circuit further comprising a low-battery detection circuit that is enabled by the microprocessor in the operation mode for measuring a voltage of the battery and disabled when the microprocessor is in the sleep mode;

a communication port connected to the microprocessor-based control circuit, and wherein the microprocessor is programmed to receive a read signal through the communication port and in response to the read signal to transmit the stored code through the communication port.

69. The electronic access control device of claim 68 wherein a stored access code is non-reprogrammable via the keypad.

70. The electronic access control device of claim 68 wherein a stored access code is disabled.

71. The electronic access control device of claim 68 wherein the control circuit comprises at least two processors.

72. The electronic access control device of claim 71 wherein at least one processor is shielded from external access.

73. The apparatus of claim 68, further comprising a communication port connected to the control circuit for sending data to the control circuit for writing into the non-volatile memory to form a stored code.

74. The electronic access control device of claim 68 further comprising a lock actuator comprising a solenoid control circuit for energizing a solenoid, the solenoid control circuit being controlled by the microprocessor and being enabled when the microprocessor is in the operation mode, the solenoid control circuit having first and second energized states controlled by a timer to energize the solenoid in the first energized state for a pre-selected first time interval at a first power level to move a plunger of the solenoid into a retracted position, and subsequently to energize the solenoid in the second energized state at a second power level to maintain the plunger in the retracted position for a second pre-selected time interval, the second power level being non-zero and lower than the first power level.

75. The access control device of claim 68 wherein a memory contains a limit value and the processor generates a signal to activate a lock actuator in response to the limit value.

76. The access control device of claim 68, further comprising a processor remote to the access control device configured to communicate a limit value to the access control device through a communication port.

77. The access control system of claim 68 wherein the circuit generating a wake-up signal is in response to pressing a first key on said keypad used in entering said input code comprising the first key and at least one subsequent keypad entry.

78. A battery-powered electronic access control device comprising:

a keypad having a plurality of keys and a program key mounted thereon;

at least one microprocessor-based control circuit comprising a microprocessor comprising a memory storing a code, the microprocessor being programmed to enter a sleep-mode to conserve battery power between operations and to awaken from a sleep mode upon pressing a key on the keypad used exclusively to enter a code programming operation;

the microprocessor-based control circuit operatively connected to the keypad for receiving user inputs entered through pressing the keys of the keypad, the microprocessor being configured to enter a code programming operation in response to pressing of the program key, receive an input key code through the keypad in response to detecting the pressing of the program key, and store the input key code in the memory as the access code for the access control device;

the microprocessor-based control circuit further comprising a low-battery detection circuit that is enabled by the microprocessor in the operation mode for measuring a voltage of the battery and disabled when the microprocessor is in the sleep mode; and

,

wherein the microprocessor control circuit comprises a plurality of microprocessors.

79. The electronic access control device of claim 78 wherein a stored access code is non-reprogrammable via the keypad.

80. The apparatus of claim 78 wherein a stored access code is disabled.

81. The apparatus of claim 78 wherein at least one processor is shielded from external access.

82. The apparatus of claim 78, further comprising a communication port connected to the control circuit for sending data to the control circuit for writing into the non-volatile memory to form a stored code.

83. The apparatus of claim 78, further comprising a communication port connected to the control circuit, and wherein a processor is programmed to receive a read signal through the communication port and in response to the read signal to transmit a stored code through the communication port.

84. The electronic access control device of claim 78 further comprising a lock actuator comprising a solenoid control circuit for energizing a solenoid, the solenoid control circuit being controlled by the microprocessor and being enabled when the microprocessor is in the operation mode, the solenoid control circuit having first and second energized states controlled by a timer to energize the solenoid in the first energized state for a pre-selected first time interval at a first power level to move a plunger of the solenoid into a retracted position, and subsequently to energize the solenoid in the second energized state at a second power level to maintain the plunger in the retracted position for a second pre-selected time interval, the second power level being non-zero and lower than the first power level.

85. The access control device of claim 78 wherein a memory contains a limit value and the processor generates a signal to activate a lock actuator in response to the limit value.

86. The access control device of claim 78, further comprising a processor remote to the access control device configured to communicate a limit value to the access control device through a communication port.

87. The access control system of claim 78 wherein the circuit generating a wake-up signal is in response to pressing a first key on said keypad used in entering said input code comprising the first key and at least one subsequent keypad entry.

88. A battery-powered electronic access control device comprising:

a keypad having a plurality of keys and a program key;

a microprocessor-based control circuit comprising a microprocessor comprising a non-volatile memory storing an access code, the microprocessor being programmed to enter a sleep-mode to conserve battery power between operations and to awaken from a sleep mode upon pressing a first key on the keypad used for entering an input code comprising the first key and at least one subsequent keypad entry on the keypad;

the microprocessor-based control circuit operatively connected to the keypad for receiving user inputs entered through pressing the keys of the keypad, the microprocessor being configured to switch from a sleep mode into an operation mode in response to entering the input code, receive an input key code through the keypad, compare the input key code with the stored access code in the non-volatile memory and activate the lock actuator if the input key code matches the stored access code,

the microprocessor being configured to enter a code programming operation in response to pressing of the program key, receive an input key code through the keypad in response to detecting the pressing of the program key, and store the input key code in the non-volatile memory as the access code for the access control device.

89. The battery-powered electronic access control device of claim 88, wherein the microprocessor-based control circuit includes a low battery detection circuit that is enabled by the microprocessor in the operation mode and disabled in the sleep mode, and wherein the low battery detection circuit measuring a voltage of a battery in the operation mode.

90. The battery-powered electronic access control device of claim 88, further comprising a communication port connected to the microprocessor-based control circuit, wherein the microprocessor is programmed to receive a read signal through the communication port and in response to the read signal to transmit a stored code through the communication port.

91. The battery-powered electronic access control device of claim 88, further comprising a communication port connected to the microprocessor-based control circuit for sending data to the microprocessor control circuit for writing into the non-volatile memory to form the stored access code.