Graduation Project Presentation Combination Lock Opener Prepared by: Lina Sha’er & Hala Omar. Supervisor: Dr. SamerMayaleh.
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 & 3rdnumber you have to turn to right direction, the 2ndto the left. What is Master Lock?
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 lockwith an unknown combination !(auto unlock) • Then report the correct combination to the owner ! Description of the project:
For the normal person to try the all possible combinations (40×40×40 = 64,000) It would take • 11 days+2hour+40minute = 16,000minutes !!!.. 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. To open the Lock.
1.5 4.5 8 12 14.5 18 21.5 24.5 28 31.5 34.5 38 Finding the 3rd number by finding the Gates 12 gate will be found 3rd Combinationof the Lock 5 of the gate will be whole number 7 of the gates will be half number The last digit of one of whole number will be different from the rest Cracking the lock. This number is the 3rd number of the combination
3rd number found Take this remainder Divided by 4 If it is 0 or 1 add 2 to it if it is 2 or 3 subtract 2 from it Take the remainder 12 % 4 = 0 Then add 4 to this number until you reach the highest number (39) This is the first possibility of the first number 2,6,10,14,18,22,26,30,34,38 To find the other add 4 to this number until you reach the highest number (39) Now, We have 10X10 = 100 possible combinations 0,4,8,12,16,20,24,28,32,36
Stepper Motor Photo sensors Stepper Motor Driver Arm Fly Wheel latching solenoid MASTER Lock H-Bridge Keypad LCD
PIC Port: Circuit Diagram:
Keypad: • 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. Input Output Unit:
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. Driver Units:Stepper Motora.
Driver : Stepper Motor 1- motor step angle 1.8o. 2- can turn the motor in .9oincrements. 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
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.
Solenoid Driver( H-bridge): In forward : Is=0.74 A Vs=10.8 V
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
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.
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
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).
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 . Feedback
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 . • Solution: • We add a led and resistor in series to the pins of stepper motor driver that connected with the S.M coils. Problem we Faced:
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 Recommendation: