RGB LED earrings for festivals, parties, raves, hacker events, etc. Each earring weighs about 1.8g, or 2.8g including the battery. This is comparable to most earrings.

WARNING: these earrings come without a battery. See "What's in the box" below where you can buy them.

Patterns

These earrings can be run with various patterns! Using a button on the back you can cycle through the different patterns:

1. Rotating colors, cycling through all rainbow colors with the two sides having opposite colors.
2. Red and blue ("fire and ice") rotating in a similar fashion.
3. Noise effect, using the same pattern as the "PartyColors" pattern of FastLED.
4. Fire-like animation (in red).
5. Fire-like animation but now with green fire.
6. Fire-like animation but now with blue fire.
7. Pride flag 🏳️‍🌈 colors.
8. Trans flag 🏳️‍⚧️ colors.

You can also power them down (and turn them back on again) by long pressing the button.

How to use

Insert the battery with the flat side (with markings) to the outside. The rounded side goes to the inside, pressed to the PCB. Inserting them the wrong way around won't harm the earrings, but the battery might drain quickly so check the polarity. The earring should light up immediately after inserting the battery.

You can select the mode using the button on the back. For a list of modes, see above.

Afterwards, it's best to remove the batteries and put them in separate plastic bags (included with the earrings). You can use the included wooden stick to remove them by pushing from the top - they're really hard to remove otherwise!

The batteries will typically last for over 24 hours, depending on the mode, and the type and quality of the battery. So you can use them for multiple nights at a festival. The blue color will fade first when the batteries run out.

What's in the box

• A pair of earrings. The earring hooks are made of silver.
• A protective case, to store the earrings.
• Some documentation on paper.
• Two small plastic bags to store the batteries safely.
• A small wooden stick to easily push out the batteries for storage.

Unfortunately, batteries are not included since shipping these batteries comes with various restrictions. Luckily, they're easy to find online on your local Amazon/eBay/Bol/etc under the name CR1225 (usually in a pack of 5 for a few euros). There's another type that you can use (CR1220) but be careful since these might fall out more easily.

How they are built

These earrings use an STM32L031 microcontroller to control the 36 RGB LEDs with Charlieplexing. By using Charlieplexing, it is possible to control all 36 RGB LEDs with just 12 GPIO pins - many more pins would have been needed with traditional multiplexing.

These earrings are assembled by JLCPCB. Since it's all open source, you can do this yourself if you want.

Open Source

These earrings are open source! The design files and the code is on GitHub, see the documentation link below.

The firmware on the earrings is written in the Go programming language (yes, really) using TinyGo. Controlling the LEDs is done directly in assembly due to the tight timings, but the animations are all done in Go. See the documentation link below for the source code. So if you feel like it, you can even program your own LED animations! Of course, they come pre-programmed so you don't need to do anything special.

I got inspiration from the really cool earrings made by California STEAM, also here on Lectronz. Check them out!

It may take a few days for me to send the package.

Currently, all packages are sent via normal mail and and will fit in a standard letterbox. You don't need to be home to receive the package. If you want other options (or no shipping option is available), please message me.

Import fees outside the EU are the buyer's responsibility. Check your customs for more information.

I'll be at 39C3 in Hamburg. If you want to buy something, you can also get something there (but please message me so I know to take enough earrings with me!).