Linnett B.

Linnett B is my name. I am a rising sophomore at Promise Academy 1. My main project is  the Arduino Laser Detector with Keypad which is a laser based security system. I honestly chose this because I think its really cool.  My starter project is the MintyBoost which is a small battery powered USB charger. I picked the minty boost because I think a portable charger might really come in handy for when I need it.


Before BlueStamp, I didn’t know much about engineering in general. I can now say I know the basics of coding and understand the concept of engineering. I learned that not only can I come up with ideas, I can create these ideas as well. Overall, it was a great experience that helped me get grasp of general engineering and help me in my potential career path.

Linnett B
Area of Interest
Electrical and Mechanical Engineering
Promise Academy 1 HS
Rising Sophomore

Final Milestone

My final milestone is about getting my keypad and laser to both function together using my code. What I did was I coded my keypad to have a code that functions with a password after pressing pound. I used pound to enter my password after typed in. When the wrong password is typed in the red LED lights up and the serial monitor displays Access Denied. And when the right password is typed in the green LED lights up and the serial monitor displays Access Granted.  After I got this to work I coded the lasers to turn off. I had to learn about for loops and character arrays to be  able to type a string of characters together to make the password.

My code

My Bill of Materials

Second Milestone

My second milestone is me coding the photocell to read the laser values to have the buzzer beep if the beam is broken. First I put in the buzzer and spent my time coding it so that when I press 0 the buzzer makes a sound. Next I put in the photocell but I didn’t know how to use the photocell so I had to research the purpose of it. I learned that the photocell acts as a light detector and the purpose for it is the laser. I then put my laser in and then realized that the laser I had could not make a straight beam so I had to get a different laser to use for my project. Once I got this laser I started to code. But when I tried to code it wouldn’t work so I had to use a different method to program it. I used analogread which reads values of analog pins, but I also had to learn about voltage dividers, ohm’s law and about mapping values. I then used the photocell to read the values of the laser when its on, off, or broken.  After learning this I came to class and coded the lasers to buzz if the values were lower than a certain number and it worked. Next I will code it so that my laser will turn off when the code on the keypad is put in.

First Milestone

   My first milestone is about the keypad in my arduino laser detector. The keypad functions as the place where the code is typed in when the laser beam is broken. First to get started I had to see the schematic of the keypad and the connections of which pin should go to header on the arduino. After researching and comparing to other projects like mine I had to draw out the whole schematic of my keypad and arduino connecting. I connected the pins of the keypad onto the headers of the arduino based off of the project link. Since I had the connections I started on the the code. I didn’t know much about coding so I just used the code from the project link. But I soon realised that the person from the project link used a different keypad from me and I had to make my own code from scratch. I knew nothing about code so I had to research the language of coding. I learned things such as setup and loop and that they are the structure for functions such as pinmode, digitalread, and digitalwrite. I also learned how to use data types such as char and int to create variables. I wrote ‘if’ statements that help connect each button on the keypad to its correct number. I finished my coding and then uploaded it to my arduino but the numbers were all over the place so I had to use a breadboard to make twelve different connections that allowed 5V to flow to the pin then touch the resistor and go to ground. After making the connections I upload the code and type into the serial monitor to see if the keypad works and it does.

Starter Project

For my starter project I built a small battery powered USB charger. The first part are the resistors. Resistors are able to stop and slow down the electric current. The capacitors are used to store an electrical charge. Next is the diode which allows current to only flow in only one direction. The diode presented a challenge when I soldered it backwards and had trouble removing it. Then I placed the IC socket which helps hold the chip. So then power inductor stores current and converts low voltages to high. Lastly i insert the boost converter chip. Then I plugged up my phone to see if it would charge and it did so this project was successful.

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