SafeMate

Inspiration

Sharing a room in college can be difficult. If you are tired of losing items and are not sure how they are disappearing, chances are your roommate or friends may be "borrowing" them without telling you.

Living in a college dorm, especially in shared spaces such as double and triple rooms, it seems that there is a loss of privacy. This can become problematic if one wants to store important personal belongings away, such as passports and identification documents or high value goods. We felt this was an issue we could resolve while making security more elegant and chic.

What it does

You simply insert the self-contained SafeMate lock module into your cabinet or drawer, and make sure that it has plenty of power. The device can be locked and unlocked using our custom-built android app that employs a customizable password that must be unlocked using voice recognition. You may also operate the device via the SafeMate controller module, which utilizes a PING sensor operated password, where you wave your hand in a specified order of distances to lock/unlock the lock.

MVP Video Demo: https://youtu.be/TP0sWWw1yxo

How I built it, what worked, and what didn't

We divided our project into its two components, the ping sensor and the mobile app. We built each component step by step, slowly adding and testing each functionality along the way. The ping sensor and its code was smooth to implement and worked quite well. Connecting bluetooth modules was one of the biggest struggles for us, especially when attempting to connect to the phone. Many times, the bluetooth modules would stop pairing and we would have to manually reset them. Implementing voice recognition also posed a problem, so we used AppInventor’s built-in capabilities for the voice recognition subject. Servos kept not functioning or blowing out, so we had to use continuous motion servos even though positional rotation servos suit our needs more effectively. As both of us own only iOS devices, we are grateful to our friends in ESE for letting us borrow their Android devices to test our app. Once we had sorted out the bluetooth module pairing, the AppInventor app worked quite smoothly.

Tech Specs

Our devices were built using the Arduino® hardware/software interface. We used two modules, one that connects to the lock, and one that is kept outside of the cabinet to control the lock. We used one pair of HC-05 bluetooth modules to connect the lock mechanism to the Ping sensor, and had a single slave HC-05 module that connected the lock to the smartphone app. The app was developed using MIT AppInventor.
The lock is operated by a continuous motion servo motor that rotates in one direction to lock the cabinet, and in the opposite direction to unlock it. The lock servo attachment and stand were custom designed in solidworks and cut out of ¼ inch acrylic using laser cutters.

Marketability

Our product has high marketing potential, with the possibility of further extending its scale to include doors, wardrobes, and iOS devices. Thanks to the casing made using SolidWorks, SafeMate is compact, portable and flexible in that it can be applied to any cabinet or drawer with a groove, thus increasing its marketing value. The arduino that houses the slave bluetooth module is powered by a battery pack so that it can permanently stay inside the cabinet, only being addressed when the battery pack runs out of charge. SafeMate’s marketing value could be increased if the mobile app were made available to iOS devices as well, thus increasing its target audience.

What we learned

We gained problem-solving skills and learned how to overcome adversity. We gained experience coding for Arduino. Kieran learned how to use SolidWorks and the laser cutters, while Anush learned how to program his own android apps. Perhaps some of the most important skills we learnt were patience and determination. Many times, parts of our project would stop working for no foreseen or logical reason, and we would have to retrace our steps, break down the problem and think critically in order to solve the issue. This also taught us to divide the project into smaller, testable sub-projects. For example, we tested the ping sensor alone before adding the LED and bluetooth components to the Arduino. After spending numerous hours in Detkin Lab, we can both affirm that this final project has been incredibly rewarding and has taught us a lot along the way.

Arduino Code

Slave code 1: https://drive.google.com/open?id=10zsQhIBdDfvBEBdXmEUYB2vjEbHlWty6

Slave code 2: https://drive.google.com/open?id=1sKnTAxKidosZ2d0qebPGLOc21057Ige6

Ping code: https://drive.google.com/open?id=1O7aBlhDQgjp7yXwzVOB3MBRENcU1Etpm