Matthew W.


I’m Matthew and I am a rising sophomore at Glen Ridge High School. For my final Project I decided to build and program a solar-powered USB charger based on this idea by user cdvalenti. I chose this project for furtherment of my passionate interest in renewable and environmentally friendly resources. I also want to help develop my skills in engineering and programming, all in a subject that can only be beneficial to everyone.


The reasoning behind my enrollment in the Blue Stamp program was the hope for a great outlet or exposure to engineering, mechanical and software based. Not only did the program exceed my expectations, but I feel as if my life and views have changed after leaving Blue Stamp. Previous to this program, I have had little-to-no experience with code and the basic engineering. Not only did I develop as a person by strengthening critical thinking and troubleshooting skills, I also met great mentors and people, and made new friends that I shared great times with throughout my 6 weeks here. Pushing through problems led to skills I never once thought I could possess but never did I think that I could design, code, and engineer for something I created like I did in this program. In sum, Blue Stamp engineering has been the highlight of my engineering career so far, and has helped my interests in engineering blossom into ideals I will use for the rest of my life.


Matthew W.

Area of Interest

Environmental and Civil Engineering


Glen Ridge High School


Rising Sophomore

Final Milestone

My third and final milestone was the development and coding for a Arduino Pro Mini and the construction of a 3D printed, CAD designed case, and the final production of a case filled with my battery, solar panel, and components from modifications. This process began with the realization that to code my project’s components with an arduino, the system had to be switched to the Arduino Pro Mini. This was because I did not want my project to be powered externally, and my Arduino UNO needed 5V to be powered. But my battery can only supply 3.7V so the Arduino Pro Mini could be powered by it. This process took a good amount of time but with the completion of uploading that code onto the Pro Mini, I can now power and have my project operate completely independently without any external powersource (obviously as long as the battery is charged). To tie my whole project togethers I designed a CAD model case for all of my components. This required me how to use and learn the program AutoDesk Fusion 360. All together, I created a portable USB charger that requires no external power source besides just the sun’s energy.



Second Milestone

My second milestone was the development and the coding of the LCD display and battery babysitter  to (1) work with code made from scratch and (2) then work  together to read the state of charge of the battery (SOC) and then taking specific information gained to then display the current charge of the LiPo battery on the LCD display. This process began with the process of research and educating myself on how to use Arduino program and how to code within it. This took me some time but I did get through it and successfully constructed a code that does everything I need it to do. This code begins with the Battery Babysitter chip beginning to read different statistics about the LiPo battery like the overall charge, the voltage of the charge, and the full capacity of charge of the LiPo battery. The code then reads to take the SOC of the battery and use it as an ‘x’ variable. This ‘x’ is plugged into a part of the code which displays the percent of battery, making the LCD Display update constantly, then display “Charge Level: x%”. Throughout this process I had to learn a lot! Arduino as whole was completely uncharted territory for me in regards to coding. As well as coding, the LCD display was hard to learn first but had many features that makes my overall project that much better and efficient. But once I picked up the basics on both of these concepts the process became more simple. But now any device that can be charged by a USB cable can now be charged efficiently with almost no trouble. My third and final milestone will be the designing of a case to hold all of the chips and wires and battery and have the display and solar panel on the outside.this will require me to learn a CAD software (Sketchup) and then correctly print it to fit all the components (ports, panel, display).

First Milestone

My first milestone is the completion of the circuit from solar powered energy directly into the USB compatible port using a Sparkfun Battery Babysitter chip and an Adafruit USB Power Booster chip. This involved learning how to solder, wire circuits, and discovering different ways to troubleshoot different types of problems. I had to research and learn about the different chip’s traits of which I was using. This involved finding the right connections for wires to help create a solid connection from the battery to the solar panel, then the battery to the USB charger chip. In the end, all problems and small discrepancies were resolved, solidifying a great connection and flow of power through the circuit, which is able to charge a USB connected device, for example, my iPhone 5S. This process began with the soldering of two ports that my Battery Babysitter chip and Power Booster chip needed to connect to the battery and solar panel. The solar panel that was provided had a plug connection that wasn’t anywhere close to the connection that my JST port needed on my battery babysitter chip. So this meant that I had to strip the end of the solar panel’s wire and pull out each individual positive and negative wire. I then inserted each wire and screwed them down to create a stable connection so the battery could be charged. Another problem I faced was the task of connecting the two chips. I had to solder on wire pins to each chip, research each male pins job and connection with the circuit and then connect them to finally get the solar power straight into the USB charger. I’m thankful that I learned more about how solar panels work and how to work with small chips that have very specific tasks and how to make them work together with just some wires, research, and critical thinking! For my next milestone I will be using Arduino to program a display to show the current charge of the battery of the charger. This will include totally learning how to code with the Arduino software and using the Arduino UNO chip.

Starter Project

For my starter project I assembled a mini-voice changer. This circuit uses components like a microphone, capacitors (electrolytic and ceramic), resistors, buttons switches, (2) IC hubs and chips, LEDs indicating power status and circuit activity, and a 9 volt battery to power the whole thing. In sum, how it works is the microphone takes sound waves and converts it into digital signal. These signals are sent to the this modulating IC chip, and the current is modulated based on the switch buttons activated in order to change your voice. After those electric currents are ‘changed’ they are sent to the the amplifier chip, and the modulated voice will have its volume and pitch will be determined by the switches. These signals are then sent to the speaker to play the modulated voice. This process was also ran in part by the resistors, which slow the energy flow, and the ceramic and electrolytic capacitors help absorb and distribute spikes of energy within the circuit, between the different IC chips and modulating components creating a smooth flow of energy and overall perfecting the process. A problem I ran into is the discovery of a faulty microphone sensitivity peripheral, which seemed to be disconnected from the entire circuit. This was eventually fixed by the resoldering of the solder joints, which finally connected it to the rest of the components. In this project I learned and was introduced to concepts and functions like soldering and resoldering, understanding engineering instructions and open versus closed circuits, while also learning how capacitors and resistors work within my project and how they can be integrated into any other circuit board task.

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