The entire premise of this project was quite simple: I, and so many other first-year students at my university, quickly got tired of locking and unlocking our doors (e.g., when merely going to the bathroom, across the hall). So, while the solution of many was to simply keep their doors unlocked, I decided that I would try to engineer a solution to this problem, mostly for the purposes of expanding my knowledge of such IoT devices, as well as some very basic soldering & electrical engineering.

The end result? Well, when it worked – i.e., for a cumulative total of maybe 20 hours – the device pinged my phone and my roommate's phone. It would unlock the door if either of us were in range (≈ 30 ft.), and would lock otherwise.

It did this via Bluetooth, and the nice thing was that there was no setup necessary. One of the overarching goals of this project was to make it as convenient as possible; it had to be more convenient than carrying a key with me. So, there was no app needed. Bluetooth pairing wasn't even required! The device recognized our phones by their Bluetooth MAC addresses.

• Raspberry Pi
• This was my first project with Raspberry Pi, where I learned the basics of GPIO, of working with logic-level voltage, etc.
• Soldering
• For the longest time, I had no idea how to solder. I would see people talk online about fixing things "simply" by soldering, but up until this project, I clicked away every time I saw that something involved soldering. Finally, I was deterined to learn, and I felt incredibly liberated. Suddenly, instead of only knowing how to plug-and-play, I could make novel connections and entire circuits of my own, not needing someone else to have done the work before me.
• Python
• While I knew Python before, this project involved multithreading and direct use of hardware. Once complete, it was the most extensive project that I had done in Python (and probably my most extensive project, period).

Thank you very, very much to the following people for their help and support on this project:

• My awesome friends
  
  Thank you so much to all of my awesome friends – of course, for so many things, but also regarding this project. Zach, in particular, was super enthusiastic and helpful throughout the entire year. I still remember that one day that we spent nearly all afternoon in the Colab planning it all out :)


• My roommate, Christian
  
  I have a lot to thank Christian for, and just one of those things is his agreeing to let me strap this half-functional monstrosity of a device to the back of our dorm room door. Thank you for letting me inconvenience you for the goal of getting this project to work. Also, sorry about that one time that I spilled an entire cup of milk on our carpet.