This was my first year at BlueStamp. My counselor introduced me to the program, saying it was not only a good way to experience engineering, but also a great way to see how a competitive summer camp works. Throughout my three weeks at BlueStamp, I grew the most in the electrical aspect of engineering. My main project required the use of an Arduino, so I learned how to code in Arduino, a “basic” version of C / C++. The Arduino IDE included a serial monitor, which could be effectively used to debug code whenever necessary. There were also many components to my project as well, so I had to experiment with different circuits using breadboards and PCB’s, or printed circuit boards. Every circuit had its own issues, which I solved through troubleshooting, whether it be with a simple multimeter, or by using a remote power supply. Other times, adding solder to fix connections was the key. My background in coding and robotics definitely helped, but even still I gained a lot of knowledge, which I can apply moving forward.

After 3 weeks, I have finished my main project – the fingerprint scanner and keypad safe. The most difficult part was probably moving everything to a PCB. At first, the circuit didn’t work, and I spent hours using a multimeter, testing voltages around the circuit, trying to find out where a faulty connection existed. After fixing the circuit, I cut out a hole in the corner of the box, and turned it into a flap so I could remove the battery. The safe stays locked by default, and can only be unlocked if connected to power. I lined up the two L-brackets so they would function as a lock, then put all the components to their corresponding spots on my safe. And when I thought I was done, I connected the power, flipped the on switch, and … nothing worked. I took the Arduino and PCB off, went through another round of troubleshooting, and re-soldered some suspicious looking joints. I then re-applied everything to the safe, tested the circuit, and it worked! I secured all the components down with bolts or glue, and finally, I was done. So with 3 weeks of hard work in the bag, I conclude my time at Bluestamp 2018, and proudly present, the fingerprint scanner and keypad safe.

Getting to my second milestone was surprisingly a lot more difficult compared to my first, despite only adding a fingerprint scanner and some few code changes. I struggled with getting the fingerprint scanner to work, trying out multiple circuits before realizing that it was the connector that was broken. After getting a new one, it worked instantly. The next issue I faced was current draw. The Arduino could only supply up to 500 mA (milli-amps), and I had just too many components, drawing too much current. Because of this, my servo would start erratically twitching. This was solved by adding capacitors, diodes, and resistors, to smooth out the AC (alternating current) current. The servo barely twitches now. However after testing, I discovered that I only needed a diode, saving a lot of space on the breadboard, as well as reducing the number of components one would need to recreate my project. Despite all the challenges, I am now done with the software and circuitry part of my project.

Besides the fingerprint scanner, I also added a three try fail safe. If someone fails to enter the correct password three times in a row, the system exits and a loud alarm goes off. Same falls for if the fingerprint is incorrect three times in a row. I also changed the battery input. Originally I used the USB port on the USB to provide power from my Anker. Now, I’m using a micro USB breakout board that’s connected to the breadboard.

For my next milestone, I plan on moving the whole circuit onto a PCB, then integrating everything into the tool box. If possible, I will also make a hole so you can remove / change the battery.