May 2024
Graduation Cap
I had the idea to make this project after my art teacher in school gave us large square stickers
that could be drawn on and put on the top of a graduation cap. He said, "Decorate them however you like,"
and I took that statement literally.
Hardware
The circuit works by the 9V battery passing through a voltage converter, the light brown board,
which reduces the voltage to 5V. This travels up to the circuit that sends the instructions to the LEDs, the green circuit board.
The green circuit board contains a pre-programmed chip removed from an arduino, the ATMEGA328P chip.
It was rewired for a smaller, permanent, form so it could fit well on the cap.
The green circuit board was made by me using KiCad based on
schematics from this guide.
Software
The light pattern is based on a sine wave. The program simply loops and adds a small percentage of 2π every time it goes around.
once it reaches 2π, it resets back to 0. It uses that number to display the pattern on the LED array
by modifying the output of the sin() to match indexes on the array.
Unfortunately, I do not have the KiCad circuit board file or the code on the chip.
They were both stored on a school computer and were deleted soon after I finished the project.