Light-up costumes using LEDs are delicate. Wires break, connectors, fail, and dust or water can get into the tiniest cracks in your enclosure, causing short circuits or rust.

And yet, most of our LED costumes are dreamed up, built, and created to be taken into harsh environments. We want to wear them to festivals in the desert and have them glow all night. We want to dress our wiggling, squirming kids up in lights so they can trick-or-treat on Halloween Night.

We need our costumes or art cars to stand up to assault by excited bystanders who can't resist poking, touching, and tugging on our beautiful creations. They need to be able to weather windstorms and rainstorms, long hugs from strangers in the dark, immersion in cuddle puddles, or pole dances on a moving art car, deep in the playa. They need to work every time we turn them on, without an hour's worth of repairs needed after every appearance.

This tutorial will give tips and tricks on design, build, and maintenance for costumes that Will Not Break. I'm using my favorite example: my light-up swimming mermaid tail.

You think the playa is a challenge? Try wearing your LED costume in the ocean. 


I'll be honest.. this guide goes a bit overboard in terms of durability. Most readers don't actually plan to submerse their costume in salt water, and you, gentle readers, are wiser than me. Making a swimmable light-up mermaid tail is a pie-in-the-sea project, and even with all these precautions, my Mermaid Glimmer tail is still a nightmare to keep running. LED projects are salty beasts.

Wearing batteries underwater is dangerous. Doing professional performances is very stressful when I'm never 100% sure the tail is going to light up at all, or stay lit in the water for even half an hour. I've spent countless hours repairing and replacing wires and lights and controllers that got wet because I didn't close my case properly, or simply wore out because salt water is very hard on electronics. 

This guide will impart some of the knowledge I've gained from years of trying to do the impossible: swim around in the sea with lights on. But all of it will translate into very robust and durable land-based costumes.


Since this guide focuses on durability, I'm keeping the wiring and coding as simple as possible. You will need rock-solid soldering skills, and a good healthy dollop of patience. A little extra time and care during the build process will save you hours of repair time down the road.

Your project can be as simple or complex as you make it, but remember: the more fancy elements you add, the more potential failure points you have. 


I'm using a tiny QT Py ESP32 Pico for my project. It doesn't have a lot of extraneous bits or sensors, and it's really small and affordable, so if it gets fried, I can replace it fairly easily. It works with WLED software, which is really easy to install and use to create complex light animations, even if you're not a coder.

If you want to add sensors or interactivity, check out the Adafruit line of Feather boards

Angled shot of purple square-shaped microcontroller.
This dev board is like when you're watching a super-hero movie and the protagonist shows up in a totally amazing costume in the third act and you're like 'OMG! That's...
1 x USB C cable
USB C Cable for Programming

If your project is using NeoPixel strips, Adafruit carries this handy BFF "backpack" that attaches to the QT Py with headers, and gives you a handy port for plugging in your lights.

Video of a driver board lighting up an RGBW half-meter long LED strip.
Our QT Py boards are a great way to make very small microcontroller projects that pack a ton of power - and now we have a way for you to quickly add a


I'm using NeoPixel Dots for my project. The dots come in 2" or 4" spacing, and come 20 to a strand. 

You could also use NeoPixel strips, rings, or any of the huge variety of NeoPixel formats Adafruit carries in your costume. But in my experience, strips break. They are flexible in one direction but very delicate in every other direction.  Rings are sturdy but the connections are tiny, and tend to break also.

These NeoPixel dots are potted in resin and wired up with very strong silicone-coated wire. They are very hard to break. It's possible, but you really have to work at it.

Adafruit NeoPixel LED Dots Strand - 20 LEDs at 2 inch Pitch
Attaching NeoPixel strips to your costume can be a struggle as the flexible PCBs can crack when bent too much. So how to add little dots of color? Use these stranded NeoPixel dots!...
Adafruit NeoPixel LED Dots Strand - 20 LEDs at 4 inch Pitch
Attaching NeoPixel strips to your costume can be a struggle as the flexible PCBs can crack when bent too much. So how to add little dots of color? Use these stranded NeoPixel dots!...

Battery Power

I'm using a 2000mAh lithium battery to power my project. This battery fits perfectly inside a GoPro Hero 4 case and will power lots of lights for several hours. 

Get a second or third one to keep on-hand if you want to run your costume all night.

2 x Battery
Lithium Ion Battery - 3.7V 2000mAh
1 x Battery Connector
JST PH 2-Pin Cable – Male Header 200mm
1 x Battery Charger
Adafruit Micro Lipo - USB LiIon/LiPoly charger - v1
Warning: Lithium Batteries are Dangerous

If your project is meant to be worn by kids, or if you plan to get it soaking wet, you may want to consider using AAA batteries instead. Lithium batteries can be dangerous things. If they get punctured and wet, they can catch fire or explode. I'm an adult, I've been making LED costumes for years, and I know the risks, so I'm using a less-safe option so that I can use a smaller enclosure box. 

1 x AAA Battery Box
3 x AAA Battery Holder with On/Off Switch and 2-Pin JST


To keep our microcontroller and battery safe from the elements, we need a good dust-proof enclosure. I'm using a repurposed GoPro Hero 4 camera case. It's rated IP68 (waterproof down to 147 feet). 

In order to get the power, ground, and data wires through the case I'll use a cable gland. These are purpose-made to create waterproof wire pass-throughs. 

I'll also use a waterproof connector to attach the controller box to the costume.

1 x Cable Gland
Cable Gland PG-7 size - 0.118" to 0.169" Cable Diameter - PG-7
1 x Waterproof Connector
Waterproof Polarized 4-Wire Cable Set

Sealing Wire Connections

We have sturdy light strands, but they still need to connect to our microcontroller and to each other. The solder joints tend to be the weak point in most projects. Here are some products that will help keep your joints rock-solid.

3 x Silicone Stranded Wire
Silicone Cover Stranded-Core Wire - 2m 26AWG
1 x Standard Heat Shrink
Heat Shrink Tubing in various sizes
1 x Clear Heat Shrink
3/4" Clear Heat Shrink Tubing
1 x Ribbon Cable Wire
Silicone Cover Stranded-Core Ribbon Cable - 4 Wires 1 Meter Long - 26AWG Black

Tools & Accessories

  • Heat Gun
  • Hot Glue Gun
  • Soldering iron & accessories
  • Cable ties
  • Power drill with a 15/32 (12mm) drill bit for the cable gland install

This guide was first published on Nov 02, 2022. It was last updated on Mar 08, 2024.

This page (Overview) was last updated on Mar 08, 2024.

Text editor powered by tinymce.