Lock Box

Overview

Everybody has something valuable which they do not want to be stolen. We are making a lock box to protect your staffs. We would have a (four input) code that the user can unlock the box with and reset. Then we would also have a backup code that is much longer (maybe eight inputs) that can be used to reset the temporary combination in case it has been forgotten. We would also have a button that the user presses to indicate what they want to do: one press for entering the short combination to unlock the box, 2 presses to reset the combination (after entering the correct combination first) and third, holding down the button to reset the shorter combination by using the longer backup combination. We also think that it would be good to have two LED's on the front: one green and one red. They would indicate the expected input. For example, the red light would be on when it is ready to take the combination, if the user gets it right, the green would turn on, but if the combination entered is wrong, the red one would flash. We would do different variations of this for resetting the combination. We will use Hall Effect sensors and magnets to make our lock. The Hall Effect will detect where the dial is pointing at by detecting the intensities of different magnets.

Team Members

Yuanxiao Gao
Samuel Hoff
TA: Mo Wu

Objectives

Make a box that is is able to be unlocked by putting in the correct combination. The combination will be entered by turning a dial, just like combination padlock. When the dial turns to a specific number, there will be a signal sent to an Arduino. When the user wants to enter a code he will press a button to select the action he wants to perform (change the code or unlock the box) and then enter the code with the dial. The way the number will be translated from the position of the dial to a number of the code is by using a Hall Effect sensor to detect a unique signal from the magnets. There will be two codes: one that is 4 digits long and one that is twice is long. The first code is changeable and when entered can both open the box and allow the user to change it. The second is a backup code that allows the user to change the first code, in case the user forgets the code.

The main goals of this project are to:
1. Design a dial and housing that allows the dial's position to an Arduino.

2. Build the interface that allows the user to specify which code he will be entering.

3. Write C++ code on Arduino IDE that allows the user to control the box.

4. Design the locking mechanism and the bottom part of the box.

5. Assemble and test.

Challenges

Accurately reading a number based on the position of the dial.

Writing code to perform all of the functionality desired.

Finding a proper power supply.

Budget

LEDs
3-D printing
Locking replay motor (4.95$)
magnets X 55 ($2.99 for all of them)
Hall Effect sensors X 13(2.38$ for each)
Buttons (.35$)
Arduino UNO

Gantt Chart