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Digital Code Lock System

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Shandong Chai, Yichen Weng, Haorui Jiang

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Introduction/Features

Digital Lock System

Team 7 designed a digital code lock system to open/close a door lock automatically coordinating with light sensor and alarm. This design also consists of a bluetooth communication to allow administrator can control the mode of this lock and the visitor can enter the password from a keypad which is placed on the outside of the door to open the lock.

Features:

  • A door lock mechanism that can be closed and open automatically depending on different mode of this system.
  • A digital keypad can be used to enter the password for opening this lock.
  • The light sensor will be activated when the lock system is at night mode and anyone who tries to open the door will activate alarm.
  • The administrator can use cell phone to connect this system via bluetooth to open the lock without entering password.

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Lock Mechanism

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The mechanism for this system is a single sided deadbolt, a stepper motor and a wood door model. When the motor controller receives the signal from microcontroller, it will turn on the motor. After a few seconds, the lock will be locked automatically.

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Lock Mechanism

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To ‘close’ and ‘open’ the lock, the stepper motor will connect with the deadbolt by a motor shaft. Spinning two ways can open/lock the deadbolt.

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Light Sensor/Alarm

Features:

  • At night mode, the door can not be opened via password
  • Only activated at night mode

Approach:

  • Attach sensor on the door
  • Microcontroller detects significant changes in analog input
  • Turn on/off the alarm by the read value from light sensor

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Control features

  • Two operation modes: day mode vs night mode.
  • Two limit of time to enter password: limit of times with no waiting penalty & limit of times with no alarm.
  • bluetooth control by the administrator.

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Day

Night

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Administrator control

Accept password/Penalty for wrong password

Deny any password/Senor activated/Protect administrator

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Help others open the lock remotely without giving the password/Change modes

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Mode depends on the time in real life

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Cost

Category

Price

PCB

$62

Mechanism(motor, deadbolt, etc.)

$70

Other (cap, resistors, etc.)

$246

Total

$378

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Future Improvement

  • Modify power supply circuit for stability
  • Add alert functions on administrator’s smartphone when alarm is activated
  • Encrypt the connection between the bluetooth on smartphone and board
  • Improve sensor system to make the lock close once the door are closed

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Experience from ECE 453

  • Separate designs of power supply board and interface board
  • Bluetooth communication
  • Psoc 4 programming and applications
  • PCB design and order
  • More experience on module configuration and testing

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