1. Combination Lock Opener
Graduation Project Presentation
Combination Lock Opener
Prepared by:
Lina Sha’er & Hala Omar.
Supervisor: Dr. Samer Mayaleh.

2. What is Master Lock?
It’s A kind of Locks that you have to select a set of digits –combination- in order to open it.
However , people sometimes forget their combinations. then need to buy a new one.
It's very important for a person to know his old combination lock.
Our lock is a Master lock 1500D.
This lock the most commonly used brand.
Have 3 numbers every number consists of 2 digits at most with a 40 *40* 40=64,000 possible combinations.
The 1st & 3rd number you have to turn to right direction, the 2nd to the left.

3. Description of the project:
The main goal of our project is to create a device that:
Open the Lock when the person insert the correct combination.
can open a combination lock with an unknown combination !(auto unlock)
Then report the correct combination to the owner !

4. To open the Lock.
For the normal person to try the all possible combinations (40×40×40 = 64,000)
It would take
11 days+2hour+40minute = 16,000 minutes !!!..
With the new algorithm developed in this project to Crack the lock resulted in reducing the number of the possible combinations to 100 possible combinations.
To try these 100 combination it takes
ONLY 30 minutes !.
In our project these 100 possible combinations using PIC16F877 microcontroller takes less than 7 minutes at worst Case.

5. Combination of the Lock
Cracking the lock.
1.5
4.5 8 12
14.5 18
21.5
24.5 28
31.5
34.5 38
3rd
Combination of the Lock
Finding the 3rd number by finding the Gates
12 gate will be found
7 of the gates will be half number
5 of the gate will be whole number
The last digit of one of whole number will be different from the rest
This number is the 3rd number of the combination

6. This is the first possibility of the first number
3rd number found
Divided by 4
12 % 4 = 0
This is the first possibility of the first number
To find the other add 4 to this number until you reach the highest number (39)
0,4,8,12,16,20,24,28,32,36
Take this remainder
Take the remainder
If it is 0 or 1 add 2 to it if it is 2 or 3 subtract 2 from it
Then add 4 to this number until you reach the highest number (39)
2,6,10,14,18,22,26,30,34,38
Now, We have 10X10 = 100 possible combinations

7. Block diagram:

8. Hardware

9. Stepper Motor Stepper Motor Driver Arm Fly Wheel latching solenoid
Photo
sensors
Stepper Motor Driver
Arm
Fly Wheel
latching
solenoid
MASTER Lock
H-Bridge
Keypad
LCD

10. Circuit Diagram:
PIC Port:

11. Input Output Unit: Keypad: LCD: It is the input of the opener .
To open a known combination for lock You have to insert the 1st num. followed by # and the 2nd & 3rd .
In auto opening you have just to insert #.
LCD:
It’s the output of the opener.
it shows the unknown combination after the process is done.

12. Driver Units: Stepper Motor a.
We use 1.8˚ stepper Motor.
We choose it as we do not need to put a negative voltage across it to reverse the direction.
The motor speed is not controlled by the voltage across the thermals. It is controlled by the frequency of voltage pulses.
A stepper motor would be the most effective, because of its precision at turning certain distances.

13. This R determines the output current to the S.M
Stepper Motor
Driver :
1- motor step angle 1.8o.
2- can turn the motor in .9o increments.
3- we need 360o /(40*2)= 4.5o.
4- 4.5o /.9o = 5 half stepper motor steps to turn 1 half number on the lock.
This R determines the output current to the S.M r

14. Latching Solenoid: Its DC Latching solenoid.
We test the amount of force needed to open the latch of the lock it was 11 Newtons ,this force is applied by our solenoid.
It has 14.4 ohm internal Resistance .
The solenoid ratings 12Volts and 0.84 Amperes.

15. Solenoid Driver( H-bridge):
Pin 0
Pin1
output
Low
High
unlatch
pull
unaccepted
In forward :
Is=0.74 A
Vs=10.8 V

16. Feedback Units Fly Wheel: Half Number divisions 40 black and 40 white
Whole Number divisions
20 black and 20 white
The black mark is aligned with zero on the lock

17. Arm:
The arm is the connecting piece between the stepper motor and the lock dial.
it be as straight as possible and that it grips the lock dial as firmly as possible.
It must be light in weight so we made it from aluminum bar. And we try to be empty inside as possible to reduce its weight.

18. Reflective Photo Sensors (OPB742):
They are 3 photo Sensors.
2 are attached to the top of the fly Wheel , and the 3rd at the Bottom of the fly Wheel.
Infrared led
photo sensitive BJT
2Holes

19. And the test Result as follows:
Vmax = 4.85 volt.
Imax = 4.85/100K = 48.5 µA
(White Surface).
Vmin = 1.4 volt.
Imin = 1.4/100K = 14 µA.
(Black Surface).

20. Software

21. Combination Lock Opener Simplified State Diagram

22. Feedback How PIC Know the current Number?
The counter is initialized when photo sensor in the bottom reads black.
In auto lock we are concerned to determine half numbers .
Photo sensor in the outer radius of the flywheel counts the number of black divisions it passed then it decide the number.
And this is done along one total rotation of the dial. after this process we will have 12 readings(all the Gates).
The inner radius work the same as outer but it work after cracking to open the lock after it determines the correct combination .

23. Problem we Faced:
It was so hard to find stepper motor with such a small degree .
Solution:
We found it finally in microprocessor lab.
Solenoids existed in market having the applications that need a very little force –like opening video players.
Solution :
After suffering we found one .
There was current that follows toward stepper motor driver which destroy the first IC .
We add a led and resistor in series to the pins of stepper motor driver that connected with the S.M coils.

24. Recommendation:
The machine that we are designed Should not be used for any unlawful
purpose .
It is very good for an old combination lock that you forgot the combination to.
We shall take no responsibility for anything do from this machine

25. Cost Analysis:

26. And Now we Play the show
Play

27. Thanks
Question