Side-Emitting LEDs: Light That Glows From the Edge of Your Wearable

Most LEDs shine up at you. That's great for a status light on a breadboard, but on a garment it can feel a bit like wearing a row of tiny flashlights. This week's spotlight is the opposite: a slim strip that shines sideways, so the light hugs an edge instead of blasting you in the eyes.

Meet the side-emitting RGB strip

The Side-Emitting RGB LED Strip is a 10-pixel strip of WS2812B-style addressable LEDs (SK6812 chip, 4020 size). Each pixel is individually addressable on a single data line, runs on 5V, and works with FastLED and NeoPixel-style libraries on Arduino and ESP32. The strip is about 5 mm wide and roughly 70 mm long, and it's $4.95 CAD. It comes in a black or white circuit base. Right now the white is in stock; the black has sold out, so if you want black, check back soon.

Because the light comes out of the long edge, it works beautifully for things like:

• Straps and cuffs. Run a strip along the edge of a bag strap or wristband and the glow wraps around the edge.
• Hems and seams. Tuck it in a seam so only a line of colour peeks out. Subtle, and a lot more "fashion" than "gadget".
• Display rims. Frame a small screen or a pendant with a ring of colour.
• Model and costume details. Sword edges, visor trim, armour seams.

Things I want you to know before you buy

I like to be upfront about the quirks. This is a bare strip with no wires attached, so you'll solder on your own. The pads are small, which makes it trickier than a standard NeoPixel strip. If you're newer to soldering, practise on a spare scrap first, use flux, and tin your wire ends before you touch the pads. It also has no weather protection. I often slip them into heat shrink, which diffuses the light nicely and protects the pads from flexing.

How you'd use it: a glowing wrist strap in about an hour

Here's a quick way to try it on an ESP32 project:

1. Cut a strip of felt or ribbon to fit your wrist, and mark where the LED strip will sit along the edge.
2. Solder three short stranded wires to the strip: 5V, GND and data (follow the arrows printed on the strip so you connect to the input end).
3. Cover the joints with heat shrink so the pads can't flex and lift.
4. Stitch the strip along the edge with a few loose tacking stitches. Don't pull tight over the LEDs.
5. Wire to your ESP32: 5V and GND to power (a small USB power bank works well), and data to a GPIO through a 330 ohm resistor.
6. Load a simple rainbow or chase effect and watch the edge glow.

If you want code without the headache, the CMozGlow code generator lets you preview effects and copy a ready-to-run PlatformIO or Arduino sketch. There's more about the CMozGlow library on its product page, and it's free.

Not sure side-emitting is right? Pair it with these

If you need something rounder, the new 3-LED RGB Circuit Ring is a tiny circle of three pixels, small enough for badges, pendants and earrings, at $2.95. For longer runs, the Ultra-Narrow WS2812 strip is only 2.7 mm wide.

Want to see a build with lights like these?

My Sparkle Up Your Fashion with Neopixels video walks through wiring and programming WS2812B pixels with an ESP32, and it's a good warm-up before you tackle the smaller pads on this strip.

Grab the strip here: Side-Emitting RGB LED Strip. Quantities are small, so if you've got a project in mind, don't wait too long. And if you make something glowy with it, tag me. I love seeing what you build.