Lighting up the graduation

Graduation cap mod

Finally...

  4 years in Tech and I was finally graduating. I wanted to make this graduation ceremony special. Illuminating the graduation cap caught my interest after seeing numerous examples on the internet, especially from Jamison Go's project. I thought it would be a natural spotlight. Not too messy, but on point.


Goals for this project is to:

• learn and get familiar with using Arduino
• make color changing process gradient yet not abrupt (white to gold, gold to blue, blue to white, and so on)
• build a cool looking graduation cap

Parts I used for this build:

Plate	1/8 inch thick transparent clear acrylic plate
U-channel	Clear impact-resistant polycarbonate U-channel, 10mm inside width
LED lights	12V flexible SMD 5050 RGB LED strip lights
Controller	Arduino Pro Mini
Transistor	N channel TO-220
Switch	Rocker switch
Battery	3S 1550mah LiPo

SolidWorks model

  "hkim702" is the user ID I've been using on multiple occasions ever since I entered Georgia Tech as a freshmen. It was automatically given to me when I first made my account in Georgia Tech school website (buzzport ID). I thought it would be worth giving it some recognition. Also, I am a mechanical engineering major. Hence the "MECH. E". This plate will be laser cut out of 1/8 inch thick transparent clear acrylic plate.

Thanks Constantine Venizelos for helping out with the laser cutting!

  Laser cutting was done at the Invention Studio. The LED strip that surrounded this plate has 10mm width. Polycarbonate U-channel with 10mm inner width is used to surround the led strip and at the same time, clamp down the acrylic plate and the mortar board together. This makes everything look neat and clean.

Arduino code

  This was my first time using Arduino. It wasn't that bad. I actually regret not learning it earlier. PWM (Pulse Width Modulation) technique is used for controlling the power of each led (r,g,b).

All testings are done on breadboard before soldering

 Arduino Pro Mini was used for its cheap cost (just $2 each) and small form factor.

Final prototype for control board

  All these go into my left pocket during the graduation ceremony (Don't worry, my pocket didn't rip). Rocker switch is designed to slightly stick out of the pocket for easily switching between on/off even when the graduation gown is covering it. 3S LiPo battery that can be charged up to 12.6 volts was used as a power source. I was surprised how fragile arduino pro mini is when it failed with only 0.6V of over-volting (manufacturer states it can take max 12V). Luckily, I had another Arduino board for spare and step down 5V voltage regulator was used to power it this time.

White, Green Gold, Blue

  Color changes repeatedly to form Georgia Tech's primary and secondary colors. Theoretically red and green lights should make yellow(gold) lights. For me, that wasn't so easy and the color gold turned out to be slightly greenish...


Improvements for future iteration:

• correct color (greenish gold -> gold)
• or try another interesting idea for decoration

And yes, I will be continuing my graduate studies starting Fall 2019 at Georgia Tech!