Josh Y.

Hi, my name is Josh and I am a rising junior at York Preparatory School. For my main-project I decided to build a refillable dog water-dish based on this web page. I chose this project because has a very practical use in helping my dog, as well as because it includes sensors and is almost fully automatic which really interests me.

Throughout the 6-week program I learned so many things from how to be independent and persistent, to how to de-solder properly. Before coming to Bluestamp, i was very interested in the world of electrical engineering and coding, but i really did not have enough knowledge to get anywhere with that interest. Now with the experience I’ve gained through Bluestamp, I’m able to start doing projects at home, with a full ability to understand them and make modifications on my own.


Josh Y

Area of Interest

in Business


York Preperatory School


Incoming Junior

Final Milestone

For my third and final milestone, I finalized the code and completed testing with my project. There were a few delays in my code that were not really necessary and could be removed. I also continued to tamper with my project until it was working exactly how i imagined. One problem i kept running into was leaking. Pretty much the only solution I found to this was adding more and more hot glue, but in an actual application of this project the cups would be completely eliminated and the pump would be connected to a refrigerator. I also discarded my buzzer because in all my testing it began to get kind of annoying, but in a regular use of this project without substantial testing, the buzzer would definitely be a must. My greatest challenge however, was definitely getting the relay to switch. The 5V from the Arduino was not sufficient enough to switch the relay, so instead, I have the 5V allowing 9V to flow through the transistor, therefore activating the relay and allowing 12V from my transformer to flow to the pump, turning it on.

Second Milestone

For my second milestone, I finally got a pump, and mainly just cleaned up my project. I built the new pump into a cup, since the pump had to be in contact with water to work. I also deconstructed my breadboard and rebuilt my circuit onto a PCB board where I could solder everything to ensure better, permanent connections. I then fit everything into a cardboard box, with an opening for the sensor wires, the power wire, a USB, a wall plug, a 9 volt battery connector, as well as the pump. I also have two flaps, one vertical and one horizontal, to be able to see the internals in case of an issue.

First Milestone

For the first milestone of my main project, the Refillable Dog-Dish, I can show the basics of my hardware along with my mostly completed code. The two copper sensor wires stemming from the breadboard sense a 5V current, provided by my “power wire”, to detect whether or not there is water in the bowl, or in this case, cup. If a current is detected, nothing happens aside from the serial monitor notifying me. However, if no current is detected, the Arduino can know that the bowl is empty, and switch the relay which turns on the pump. Although at this time I do not have a pump, it is represented with a solenoid switch, which clicks in place of the pump turning on.

Starter project

For my starter project I built the Mintyboost portable USB charger. It includes a variety of different resistors and capacitors, as well as one diode, a power inductor, and a boost converter chip. The multiple resistors all help restrict the flow of electrons throughout the circuit, limiting the current. The electrolytic capacitors are used as a bank for voltage, as they can store a lot of charge in its strong electromagnetic field. The ceramic capacitors on the other hand, are much smaller, and are used to help smooth out the current as the voltage changes. The diode in the circuit is mainly just used to make sure the current only flows in one direction and does not end up flowing back into the batteries. The power inductor can store current as well as voltage in its coils, allowing for a safety, incase not enough volts were able to come from the batteries. Last, the boost converter chip helps convert the 3V from the 2 AA batteries into the 5V needed to charge a USB-powered device. It also helps to read what kind of device is plugged into the female USB adaptor. Even though this was just a “starter-project” it still taught me a ton. I learned how to solder more efficiently, de-solder, and I even learned almost all of that information on electrical components I just explained.
  • Ronnie Fiebach

    Congrats to Josh! He selected interesting and practical projects. He did a great job of explaining each of them.
    Hopefully this will lead him to an interest in studying and applying electronics, coding, and problem-solving in his future studies.
    What a great experience!!

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