Fairy LED Bracelet



Fairy LED Bracelet

Thanks to Sparkfun for this tutorial, we are now able to connect all needed components into the Blueprint.



In this project, we’ll create a wearable bracelet using Fairy LED String Lights and a rechargeable LiPo Battery cast in resin.

 Design and build time: 30 minutes — 1 hour
 Resin drying time: 24 hours

Step #1: Materials and Tools

The following shopping list includes the supplies from SparkFun that you’ll need to follow along at home.

You Will Also Need:


Product Name SKU Price Qty
NOK0.00 1
NOK0.00 1
NOK0.00 1
NOK0.00 1
NOK0.00 1
Solder Leaded - 100 gram TOL-09161 NOK53.60 1
SolderPro 50 Butane Soldering Iron Kit TOL-09450 NOK239.20 1
JST Right-Angle Connector - Through-Hole 2-Pin PRT-09749 NOK11.20 1
Polymer Lithium Ion Battery - 110mAh PRT-00731 NOK63.20 1
LiPo Charger Basic - Micro-USB PRT-10217 NOK71.20 1

Step #2: Understanding the Circuit

This project is an example of a basic circuit – an electrical loop that travels from a power source along a path (called a trace) to a component (or components) that uses the electricity to function and then back to the power source. For our project, we’ll use an LED (Light-Emitting Diode). When this loop is completed by connecting the battery to the LED leads, electricity from the power source is able to flow from the positive (+) side of the battery through to the LED (lighting it up) and back to the negative (–) side of the battery. This electric flow is called current.

LEDs, like many electronic components have polarity, meaning electric current can only flow through them in one direction. That means that it matters which LED lead is connected to the positive ( + ) side of the battery and which is connected to the negative ( - ) side. If hooked up incorrectly, they will not light up. The batteries are also polarized; they have a positive and negative side. Always check the to make sure your LED leads are correctly oriented before soldering together a circuit. You can test this by simply trying one side and then the other or by using a multimeter.

Step #3: Putting It Together

Start by sanding down the leads on the Fairy String LEDs. If you haven’t already, you will need to snip away any hardware that might have come with them to adapt to a wall or battery source.


Step #4: Silicone Mold

Place the LiPo Battery in the Silicone Mold, followed by the string of lights. Make sure you keep the sanded LED leads and LiPo connector out of the mold.

inserting 1

inserting 2

Step #5: Add Glitter

Fill the mold up with as much glitter as it will hold. (This is optional. If you don’t like or want glitter, skip this step!)


Step #6: Epoxy Mix

Following the instructions on the packaging, pour the Epoxy mix into the mixing cup and use a paper clip to mix it together. Mix slowly as to avoid making air bubbles.


Step #7: Pour Mixed Epoxy

Pour the mixed Epoxy into the bracelet mold, setting all your electronic parts and glitter inside of the bracelet.


Step #8: Wait... 24 hours

After 24 hours, remove the bracelet from the mold.


Step #9: Solder JST Connector

Find the + and - lead by using a multimeter or power source, and then solder on a JST connector accordingly.


Step #10: Connect LiPo

Finally, insert your LiPo connection into the soldered JST connector, and enjoy the light!


Step #11: Enjoy your Awesome Bracelet