Overview
The first big project in my Internet of Things course in spring 2024 was built to be creative on purpose: practice IoT skills by making art. I made a motion activated sign for the ALIC lab, the campus lab where we built everything that semester. Clear laser cut acrylic letters spell out ALIC, and when someone walks by, hidden RGB LEDs light the letters up from below.
The proposal sketch says it all: pretty glowing letters on top, a base labeled hidden components, and an arrow pointing to a super secret IR sensor. That was the whole design philosophy. The art on the outside, and the Arduino, battery, and ugly wires on the inside.
How It Works
Each acrylic letter sits in its own slot on a laser cut plywood box, edge lit from underneath by RGB LEDs, five of them across the four letters in my final schematic. A PIR motion sensor peeks through a small hole in the front of the box, and its signal runs through a 4093 logic chip before it reaches the microcontroller. No motion, clear glassy letters. Motion, and the sign glows.
Building It
It went breadboard first: one RGB LED under a single acrylic letter to prove the edge lighting would actually carry, then the motion sensor wired in so waving a hand flipped the lights, then the box build to hide every wire. My brainstorm page is full of honest unknowns, like whether to laser cut or 3D print the letters, an admission that I did not know the laser cutter's properties yet, and the extremely important question: is there an official ALIC lab font? Even my source list hedged its bets, with an Arduino pinout chart next to a MicroPython RGB LED example.
The course asked for goals up front, a pinout diagram and pseudocode before building, weekly progress notes with photos and videos along the way, and a reflection on every goal at the end, achieved or not. You earned credit by documenting honest progress, which made experimenting feel safe. It is also why this project left behind a camera roll full of glowing breadboards.