Project Overview

For this piece, I took a different approach to wearable electronic art by creating a Victorian-style ornate mirror with LEDs that shine directly through the PCB itself. Unlike my skull design which used surface-mounted LEDs, this project explores the PCB as both structure and diffusion medium.

256 APA102 LEDs shine through a white PCB with a pixellated, gaussian-blurred skull in an inner copper layer.

The field appears a completely blank white when the animation is not activated.

The result is a blurry shadow of a skull in that looks like it’s floating inside of a fire simulation.

I used the Fire2012 algorithm as basis for the animation algorithm

Design Concept

I was inspired by antique Victorian mirrors and the concept of “portals” or gateways in folklore. The ornate frame with decorative figures creates a classical aesthetic, while the illuminated center produces an ethereal, otherworldly effect—as if gazing into another realm. The contrast between the traditional frame design and modern electronic illumination creates an intriguing juxtaposition.

I was interested in doing impossible things with LEDs. I came up with the idea of having LEDs shine through the substrate using copper as masking layers to create a surprising effect, displaying a hidden image.

I was also thinking for a long time about why you couldn’t make a gray LED. It’s impossible. Gray is just a contrasting brightness. It just means something else is brighter near it, and LEDs are always going to be brighter than anything near them, sort of by definition. The LEDs shining through the white soldermask makes the surrounding white areas look unmistakably gray. It looks exactly like smoke coming out of the fire. It was a spectactular effect. So, in a sense, you could make LEDs produce gray.

Technical Implementation

PCB Construction

• PCB with ornate frame design
• Copper layers designed around central “mirror” portion to allow light transmission
• Black solder mask on the front for the frame details
• RGB LED panels positioned to shine through the semi-transparent regions

Lighting Technique

Unlike traditional PCB designs where components are mounted on the surface, this piece uses a technique where:

1. LEDs are mounted behind the PCB
2. The central oval region of the PCB is designed as a light guide, with copper as a masking effect
3. Light from the LEDs penetrates through the FR4 substrate, creating a diffused glowing effect that doesn’t look pixellated.

Hardware

• 256 APA102-2020 LEDs
• ATmega328p microcontroller

Algorithm

I based the fire algorithm on the Fire2012 algorithm originally from Mark Kriegsman/FastLED. However, it’s nominally a 1D algorithm intended for LED strips. Instead of having the columns blend warmth across them or making the columns independent I made the sparking rate per column a function of Perlin noise, and the result was really fantastic.

Learnings

This “Haunted Mirror” represents my exploration of PCBs as both functional electronics and artistic medium, using the material properties of the board itself to create ethereal lighting effects.