Hey! My name is Kadidia and I am a rising freshman at Success Academy High School. This summer was my first year at BlueStamp and I decided to do a Minty Boost phone charger as my starter project and 3D printed LED bracelet that responds to motion as my main project. I chose this project because I wanted to make something wearable and because I thought it was a really cool project.
Reflection:
I came into this program knowing next to nothing about LEDs, electrical currents and 3D Design but now I have a pretty good understanding about them. I decided to come to BlueStamp because I was interested in technology and the STEM field, and I would definitely recommend this program to anyone who is interested in STEM. I enjoyed doing the designing for this project and the coding. If I were to do this project again I would be careful not to break any of my parts so that I had more time to do modifications.
Quick Hints and Tips:
- If you are using an LED strip with more than 30 LEDs, limit the amount of LEDs lighting up by decreasing the LED number in your code.
- Be patient and prepared to face obstacles, especially if you are new to engineering.
- If at first your LEDs aren’t lighting, change the pin you are plugging the data input wire in and make sure the pin number in your code corresponds to the pin number that the data input wire is connected to. But be sure to switch back to pin 1, 3, or 4 because you need the others for your accelerometer.
- Be careful not to break your parts because it’s a pain to constantly replace them.
Schematics:
Schematics for 3.3volt Trinket. Note: Only 3.3volts work.
Libraries and Code:
3D Design:
Feel free to edit my design at:https://cad.onshape.com/documents?filter=recently-opened&column=modifiedAt&order=desc&viewMode=0
Bill of Materials:
Final Video:
The way that it works is that inside this is a mini microcontroller called a Trinket that contains code, an accelerometer that makes this bracelet motion sensored, and a 3volt battery to power this all. The accelerometer determines if the bracelet is shaken and determines the acceleration, how fast it’s going, and gives this information to the Trinket. The Trinket then tells the LEDs to light up according to the shakes and if it’s shaken twice it turns a solid color and if it’s shaken more than two times it sparkles. The Neopixels are individually controlled lights that light up based on how much of the three colors, red green and blue, are projecting. There is a 470µ capacitor between the BAT+ and ground pins, and a 470Ω resistor connecting the data The most challenging part of this project was making the code since I was new to the code software, Arduino. Also, a lot of my parts kept breaking so I had to keep replacing them, which was time consuming and the reason I didn’t have time for modifications. I had to replace my Trinket twice and my accelerometer once although I thought that I had broken the second one when I didn’t, which was really frustrating. I made the 3D design of this bracelet by myself using Onshape, which wasn’t as hard as it would’ve been if I used another designing software.
Check out my final video demonstrating my bracelet down below:
Milestone #1
I have reached my first milestone, where I tested all my components for my bracelet, including my accelerometer. I uploaded code that I wrote to Trinket which consists of various LED patterns along the individually controlled LED strip. The strip is powered through the power and ground wires which are soldered to the Trinket. I decided to used a switched JST breakout board to connect my battery to Trinket, which gives me a switch on the current as well as an extra ground terminal. The wires for the LED strip are soldered to the Trinket terminals with jumper wires that connect to the breakout board as well as with a 470µF capacitor. The capacitor was a suggestion by Adafruit to protect the LED strip, as was the 330Ω resistor that is soldered between the data input wire on the LED and the Trinket. The code is stored onto the Trinket and travels to the LED strip through the data input wire. This whole operation is powered by a 3.7volt battery. However, since the LED strip usually operates on 5volts, and since my LED strip had 60 LEDs, this proved to be a problem. I originally planned to cut the LED strip, however instead I modified the code so that it powered less LEDs which is why in my video only the first 10 LEDs are powered. I’m not precisely sure how many LEDs I need for my bracelet, and I probably won’t be until I print the model, so I won’t cut the LED strip yet. Other challenges were understanding how to write my code, since this was my first time working with Arduino although I had some experience with JavaScript. Patience eventually paid off, and I reached my first milestone without destroying anything. My last challenge was surprise surprise, the wires kept snapping, just as it did in my starter project. I did a lot of desoldering in this time period, but it was much easier than it was in my starter project and I became better at it. My next steps are to code for my accelerometer and then modify the 3D bracelet design so that I can fit all my components since I am using more parts than others who did this project used such as my breakout board and the button I plan to use in my modifications.
You can check out my milestone video and see how my LEDs work below:
(Sidebar: The LEDs seem glitchy, but it’s just because the battery was only slightly charged. Not to worry, I tested it later after charging the battery and the LEDs responded accordingly).
Milestone #2:
In this milestone, I completed my 3D Design and my code. I used Onshape to develop my own 3D Design for the bracelet instead of using the one provided, and I modified a previous bracelet code to create my own. However, the bootloader on my Trinket stopped working so I wasn’t able to test it. I should be getting another one soon. I also replaced my accelerometer in this time period. My 3D Design for the bracelet was printed in blue because their was no white fillet, so I drilled holes in the bracelet to make the LEDs visible. Right now I only have the bigger part of the bracelet because the others haven’t been printed yet. My challenges in reaching this milestone were for one thing I was new to Onshape, so it took me a while to make my design. Another challenge was that at first my code wasn’t compiling because of errors, and it turns out my formatting was wrong. I wasn’t able to check to see if the code worked now because my Trinket broke, but I should be able to find out soon.
Check out my second Milestone video down below:
Starter Project
My starter project was a MintyBoost phone charger, which can charge an iPod or iPhone. It is called a MintyBoost because not only can it boost the battery of a device, but also because it works as a boost current, which is a circuit in which the output voltage is greater than the input voltage. The project is powered with two double-A batteries, which is an input voltage of 3.0 volts. The energy flows from the battery into the current, where the capacitor smooths out the signal. The capacitor then directs the energy into the inductor, which stores magnetic energy. The IC chip, which is constantly opening and closing its switch, then tells the inductor to convert magnetic energy into electric energy until it reaches 5 volts. The energy then flows through the diode through a one way path to the USB port. The most important part of the current is the IC chip, which is basically a micro circuit that is crucial to the circuit as it directs the current’s activity. Another part of the MintyBoost is the resistor, which helps to improve the capability of the IC chip. My challenges with this project were for one thing when I first completed the current it was short circuited because of a loose connection between the batteries and the circuit board through the wires. Another challenge was the wires kept snapping, and I kept having to desolder and re-solder it’s terminal. My last challenge was that even when I had soldered all but one of my parts, I wasn’t getting the right voltages because of a broken part. My attempts to fix the circuit just made it worse, and eventually it got so bad that I had to start over. With my second circuit I was having the same issue with inaccurate voltages because of one loose connection. Finally, I was able to get the correct voltages and finish the project after 4 days.
You can view my starter project video down below:
