My Backpack
October 2012 - May 2016
Throughout my high school career, I have been adding features to my backpack. It started freshman year when I thought it would be cool to have a USB charging port. I took a portable battery, put it in a pouch, and mounted a USB port in the headphone hole so that it could be accessed from the outside.
Now that I had this USB port, everyone in school was asking to charge off of me. I needed cables. I started packing my backpack with headphones, audio cables, charging cables, and communication cables. Whatever people needed, I wanted to make sure I had it.
The next step on the upgrade train was speakers. But to power something like that, I needed a bigger battery. I found a 12v 8000mAh NiMH battery, grabbed some desktop speakers, and plugged them into each other. I wanted the speakers to be Bluetooth, so I got a Bluetooth module and hooked that into the system. My backpack was rocking, although I will admit, my bus driver hated me.
The next big upgrade came when I learned about the Raspberry Pi. My dad bought one and asked me to learn how to use it for him. I had used Linux, but only had an elementary understanding. Once I got it set up, I connected a portable screen and a wireless keyboard to make it portable. Everything conveniently fit inside a pencil case. I used the 12v battery to power the monitor and a regulator to power the Pi. About this time I had also made my homework webpage. It was an online list of my homework assignments that I could check off. To add assignments to this list, I hooked the Raspberry Pi to the webpage. We were not allowed to use phones in class, but nobody said anything about a wireless keyboard. To enter the homework assignments, I would use the keyboard to type the assignments into the webpage while the raspberry pi and monitor were still stored in my backpack.
After a while without many upgrades, I came up with the idea to add an outlet to my backpack. It was nice charging my phone, but what I really needed was to charge my laptop. I found a 12v inverter online and ordered it. I wired it up to my battery and got it working in a few days. To show it off, I was walking around my house with my backpack on and carrying a lamp that it was powering.
Then came the idea that everyone in high school knows me for. I was sitting in psychology, junior year, wondering what else I could add to my backpack. I was thinking of decorative lights, but I couldn't think of exactly what kind of lights I wanted. Then, it hit me; Turn signals! As soon as I got home, I got to work researching. My dad provided me a microchip PIC18f4685 demo board and introduced me to the programming language C. I stopped by my local grocery store and bought trailer lights I zip-tied to the outside of my backpack. I had a prototype set up in 3 days and was excited to see the looks on everyone's faces. I had connection issues with that demo board, so I borrowed a circuit board from my dad's work. I made a few modifications to the hardware and reprogrammed it. After properly sewing and wiring buttons on the front straps with conductive thread, it was all working.
Over the summer of 2016, I gained more experience with PIC microcontrollers and the language of C while working for Electrimotion. Electrimotion produces a device that contains a PIC microcontroller, a screen, keypad, and many inputs and outputs. I immediately wanted to use it for my backpack. I took the device, reviewed some schematics, and modified it to be my new backpack controller. With this new screen and keypad, I was capable of changing settings about the turn signals and controlling power to various systems. I was also able to read voltage, temperature, current, and total power draw in mAh. I also implemented over-current and over-temperature protection along with a hidden game.
I have since removed the turn signals due to a damaged battery, but I still try to keep my backpack interesting. I always carry with me a multimeter, screwdriver, 1TB hard drive, dice, cards, 2 laptops, a swiss army knife, and a flashlight.