UnlockME

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  The top of the project with the keypad that tells the motor how to unlock the combination lock

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  The area where the combination lock is attached to the motor through a 3d printed attachment

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  The interior of my hack including the hardware that was implemented

Inspiration

When I was first starting to have lockers in school, I always found it very difficult to get my combination lock open. I basically decided to create a digital and simple lock by hacking a combination lock. I later decided that such a project would be a great task for a hackathon. Thus, PennApps became the place to hack it at.

What it does

The hack grasps onto the combination lock's knob, takes an input of three 2 digit numbers from the range of 0 - 40. In a matter of seconds, one can unlock the MasterLock with ease and a digital interface.

How I built it

Effectively, I have 3 two digit numbers that need to be taken as input, something to grab and control the combination lock that can also twist with great accuracy. I acquired and programmed an Arduino Uno to be the brains of the project. I also got a stepper driver, and a stepper motor with very accurate rotation. Last but not least, a simple keypad that allows the input to be taken was implemented. The keypad takes three inputs, and the Arduino processes the inputs and figures out the way the lock should be turned. The stepper motor rapidly and accurately spins the lock and voila! You have an unlocked combo.

Challenges I ran into

Since the stepper motor does need quite a bit of power to quickly and powerfully rotate, I used a 12V power supply that I connected directly to the Arduino. However, the stepper driver would rapidly overheat causing the accurate rotations to become sloppier and less accurate.

Accomplishments that I'm proud of

I have been planning at attempting this project at a hackathon for quite some time. Even coming into PennApps, this hack was not my first choice. However, I successfully attempted the creation of this hack and I am proud of the result.

What I learned

From this hack I learned a great deal about debugging in Arduino along with fixing hardware problems and problems with software. Additionally, I learned that stepper drivers, or at least the one I have, overheat very rapidly under a 12V power supply and when it overheats, the stepper motor is wildly less accurate.

What's next for UnlockME

Further advancements to UnlockME may include creating a smaller and more compact case for the entire hack. I also would like to find a way to incorporate a battery so an external power supply is no longer in the way. Overall, UnlockME has been a great hack and has many great advancements and updates to come.

Built With

• arduino