Callie’s Page


This is my blog from my first semester at ITP. I have since switched to a Notion blog which you can view here.


Fall 2024


Intro to Physical Comp:



Intro to Comp Media:



Hypercinema:






Week 7 → Midterm Project


 Project idea:

My original midterm idea was a lamp that would dim/brighten and/or change colors when the user rotates the shade. This more tactile input would hopefully be a more satisfying and effortless interaction than the typical lightswitch setup inside the lampshade. 

Based on advice from pcomp resident Kai, I decided to make my own “DIY lightbulb” using an Adafruit Neopixel LED strip connected to a rotary encoder. 




First steps: Lighting up the LED strip, wiring the rotary encoder, and connecting them both

I used the Adafruit NeoPixel Uberguide to help me connect the RGB strip and run their test code.
I was able to follow this lab for connecting a rotary encoder to start using it as an input.
I connected the rotary encoder to the RGB LED strip. I used this code from the YouTube channel Greg’s Guide to Geekdom which was immensely helpful

Fabrication:

With the basic functionality working, I wanted to think about how this project should be fabricated. 

I went to the Big Reuse in Gowanus, a secondhand store with lots of homegoods and got some materials for the base of the lamp.  
On my way to Ikea to find a bowl I could repurpose as a lampshade, I happened to find the exact kind of lampshade I wanted!  
I needed something transparent to house the LED strip, and ideally something I could open and close for easy access. Unfortunately I had to eat all this gelato to use the container. 
I liked the “mushroom” shape of this lamp. The ceramic base is sturdy and wide enough to house an Arduino and breadboard, and the enclosed shade can hide a DIY-looking lightbulb. 



Ian helped me sauter wires to the rotary encoder so that I could attach it to the top of the “lightbulb” and thread them through to the Arduino
I modeled a knob on TinkerCAD to fit over the top of the rotary encoder 
After the first print turned out medicore (top), Ian helped me reprint the knob on the Bambu printer so that it would look more polished (bottom). 
Noah helped me laser cut a base for the lamp that would help enclose the breadboard and microcontroller 






You can see the basic setup for the inside of the lamp in this picture. The “lightbulb” is secured to the base with sticky tack, and the rotary encoder is secured to the top of the jar. 

At this point I started to rethink my original design. I still like the idea of using the shade itself as a knob, and could have easily accomplished this by securing the 3D printed knob to the shade. 

However, I felt like using the smaller knob at the top was a much more obvious and satisfying input for the design of this particular lamp (maybe because this lampshade is pretty low to the ground and the shade curves inward). But I would be interested to hear the class feedback 



I had a functional prototype at this point, but I still wasn’t super happy with the quality of the light. The rainbow RGB strip looks very “gamer” in a way that makes the product less versatile, but the pure white light created by the RGB strip is a very unpleasant blue/white color. 

I decided to increase the complexity by adding a second warm white strip, and wanted pressing the knob to allow the user to switch between these two modes. 





Lighting up the white strip with Adafruit test code
Adding a second strip:

This lab helped me understand how to set up the breadboard with a 12V power supply and a microcontroller, however I modified it a bit for my purposes with help from pcomp resident Kay. I ended up dividing the power between the 2 rails, with one side of the breadboard being supplied 12V from the power source, and the other source being supplied 5V from the regulator. The warm white strip was powered on the 12V side, and the microcontroller and 5V RGB strip on the 5V side. 

This Adafruit LED guide was a little confusing to modify for my particular model of LED (it only had two wires instead of 4), but the basic circuitry still worked to light up the LED with the Adafruit test code. 




Circuit diagram:
With this setup, we found that the 5V regulator was getting very hot very fast, so we added a heatsink which has helped the problem. We wondered if in the lab setup shown, the Arduino is helping to regulate the voltage to avoid overheating the 5V regulator? The heatsink fix was workable for now, but in order to make this a viable product it’s a problem I would want to address this more in depth.  




Code:

With the wiring done, adjusting the code took some time. ChatGPT helped me combine the Adafruit test code and the code for the RGB strip. I learned that rotary encoders are pretty finnicky to work with, so it helped a lot to use AI to deal with the math. See the final working code here: https://github.com/cpage275/pcomp-midterm/tree/main



The final project:




Materials list:

  • 220 ohm resistor 
  • 470 ohm resistor
  • 1000 uF capacitor
  • 5V regulator 
  • TIP120 transistor 
  • wire
  • 3D printed knob
  • thrifted ceramic base 
  • lampshade from a garbage can on the street
  • repurposed clear Talenti gelato container 
  • sticky tack
  • laser cut scrap wood base



Things to improve:

  • Ideally it would not be a fire hazard 
  • Use a real lightbulb, or at least think of a better enclosure for the strips so that the light doesn’t look uneven
  • Secure the components in a more permanent & more aesthetic way 
  • Return to the “lampshade as knob” idea - I think it would work better with a lamp that is shaped differently for a better affordance
Reflections

I’m happy with how this project turned out! I’m glad I challenged myself to increase the complexity, and I feel like I got a good taste of different fabrication techniques (3D printing, sautering, laser cutting).