LED Earring PCB
Custom 20mm PCB with TTP223 touch IC for capacitive-touch LED earrings
20mm PCB diameter
~40hrs Battery life
~$3 Unit cost
KiCadTTP223CR2032SMD LEDs
View on GitHub →
The Problem
Wanted to create wearable LED earrings that could be toggled on/off with a touch — no visible buttons or switches. This meant designing a custom PCB small enough to wear as jewelry.
Architecture
Architecture diagram coming soon.
What I Learned
PCB design at this scale is a puzzle — every millimeter matters. The biggest lesson was that the capacitive touch sensitivity needed careful tuning based on the actual ear’s capacitance. Prototyped five revisions before the touch felt reliable.
Results
| Metric | Value |
|---|---|
| Final PCB size | 20mm diameter |
| Battery life | ~40 hours continuous |
| Touch reliability | 98% activation rate |
| Unit cost (10 units) | ~$3 each |