# GEMMA Hoop Earrings
## Overview
https://www.youtube.com/watch?v=FrwxI9GXKUU
GEMMA jewelry! The bitty board fits perfectly in the center of a NeoPixel ring for flashy hoop earrings or a charming pendant. Read on to build your own!
Before you get started, follow the [Introducing GEMMA guide](http://learn.adafruit.com/introducing-gemma) or [Introducing Gemma M0 guide](../../../../adafruit-gemma-m0/)
Info:
https://youtu.be/oUuGXWMr3sE
# GEMMA Hoop Earrings
## Tools & Supplies
Bill of materials (for one pendant-- double this for a pair of earrings):
- [Gemma M0](https://www.adafruit.com/product/3501) or [Original Gemma](http://www.adafruit.com/products/1222) (M0 type is recommended!)
- [NeoPixel ring](http://www.adafruit.com/products/1463 "Link: http://www.adafruit.com/products/1463")
- [tiny lipoly battery](http://www.adafruit.com/products/1317) with [charger](http://www.adafruit.com/products/1304)
- pendant hanger or ear wires/jump rings
- stranded wire
- clear thread
- double stick tape
- E6000 adhesive (if using glue-on pendant hanger)
Any entry level 'all-in-one' soldering iron that you might find at your local hardware store should work. As with most things in life, you get what you pay for.
Upgrading to a higher end soldering iron setup, like the [Hakko FX-888 that we stock in our store](http://adafruit.com/products/180 "Link: http://adafruit.com/products/180"), will make soldering fun and easy.
Do not use a "ColdHeat" soldering iron! They are not suitable for delicate electronics work and can damage the boards ([see here](http://www.epemag.wimborne.co.uk/cold-soldering2.htm "Link: http://www.epemag.wimborne.co.uk/cold-soldering2.htm")).
[Click here to buy our entry level adjustable 30W 110V soldering iron.](http://adafruit.com/products/180)
[Click here to upgrade to a Genuine Hakko FX-888 adjustable temperature soldering iron.](http://adafruit.com/products/303 "Link: http://adafruit.com/products/303")
[Learn how to solder with tons of tutorials!](http://learn.adafruit.com/adafruit-guide-excellent-soldering "Link: http://learn.adafruit.com/adafruit-guide-excellent-soldering")
You will want rosin core, 60/40 solder. Good solder is a good thing. Bad solder leads to bridging and cold solder joints which can be tough to find.
[Click here to buy a spool of leaded solder (recommended for beginners).](http://adafruit.com/products/145 "Link: http://adafruit.com/products/145")
[Click here to buy a spool of lead-free solder.](http://adafruit.com/products/734 "Link: http://adafruit.com/products/734")
You will need a good quality basic multimeter that can measure voltage and continuity.
[Click here to buy a basic multimeter.](http://adafruit.com/products/71)
[Click here to buy a top of the line multimeter.](http://adafruit.com/products/308)
[Click here to buy a pocket multimeter.](http://adafruit.com/products/850)
[Don't forget to learn how to use your multimeter too!](http://learn.adafruit.com/multimeters "Link: http://learn.adafruit.com/multimeters")
Sharp scissors are a must!
Don't forget your [wire strippers](https://www.adafruit.com/products/527), [pliers](https://www.adafruit.com/products/146), and [flush snips](https://www.adafruit.com/products/152)! [Tweezers](http://www.adafruit.com/products/421)can help manipulate the wires connecting components in your circuit.
Use [needles](http://www.adafruit.com/products/615) to secure threads to the circuit.
A helping third hand tool really makes this project a joy to build.
[Click here to buy a helping third hand tool.](https://www.adafruit.com/products/291 "Link: https://www.adafruit.com/products/291")
# GEMMA Hoop Earrings
## Circuit Diagram
Info:
The NeoPixel ring's Data In pin connects to D0 on GEMMA, GND to Gnd, and Vcc to Vout.
# GEMMA Hoop Earrings
## Solder Components
Solder stranded wires to three spots on the NeoPixel ring according to the circuit diagram: power, ground, and data input.
Arrange GEMMA in the center of the ring, holding everything in place with a pair of helping hands.
Cut to length and strip the ends of the wires in order to connect to GND, Vout, and D0~ on GEMMA (referencing the circuit diagram). Tweezers can help get tiny wires in position.
Flip the assembly over and solder the wires to the back of the GEMMA pads. Be careful not to fill in the hold with solder, so that you can still thread a needle through it later.
# GEMMA Hoop Earrings
## Arduino Code
Info:
If this is your first time using GEMMA, work through the [Introducing G](http://learn.adafruit.com/introducing-gemma)[EMMA](http://learn.adafruit.com/introducing-gemma) guide first; you need to customize some settings in the Arduino IDE. Once you have it up and running (test the 'blink' sketch), then follow the instructions on the following page for installing the NeoPixel library:
## **[NeoPixel Überguide: Arduino Library Installation](../../../../adafruit-neopixel-uberguide/arduino-library-installation)**
Plug in your circuit and load up the sketch below:
https://github.com/adafruit/Adafruit_Learning_System_Guides/blob/main/Gemma/Gemma_Hoop_Earrings/Gemma_Hoop_Earrings.ino
# GEMMA Hoop Earrings
## CircuitPython Code
**GEMMA M0** boards can run **CircuitPython** — a different approach to programming compared to Arduino sketches. In fact, **CircuitPython comes factory pre-loaded on GEMMA M0**. If you’ve overwritten it with an Arduino sketch, or just want to learn the basics of setting up and using CircuitPython, this is explained in the [**Adafruit GEMMA M0 guide**](../../../../adafruit-gemma-m0/circuitpython-setup-1).
Info:
Below is CircuitPython code that works similarly (though not exactly the same) as the Arduino sketch shown on a prior page. To use this, plug the GEMMA M0 into USB…it should show up on your computer as a small **flash drive** …then edit the file “ **code.py** ” with your text editor of choice. Select and copy the code below and paste it into that file, **entirely replacing its contents** (don’t mix it in with lingering bits of old code). When you save the file, the code should **start running almost immediately** (if not, see notes at the bottom of this page).
**This project is designed to work with RGB NeoPixel rings, not RGBW.** The code will not work with RGBW.
**If GEMMA M0 doesn’t show up as a drive, follow the GEMMA M0 guide link above to prepare the board for CircuitPython.**
https://github.com/adafruit/Adafruit_Learning_System_Guides/blob/main/Gemma/Gemma_Hoop_Earrings/code.py
This code requires the **neopixel.py** library. A factory-fresh board will have this already installed. If you’ve just reloaded the board with CircuitPython, create the “lib” directory and then [download neopixel.py from Github](https://github.com/adafruit/Adafruit_CircuitPython_NeoPixel).
# GEMMA Hoop Earrings
## Affix Jewelry Findings
You shouldn't rely solely on the wires to hold GEMMA in place. Secure it in four spots with clear thread-- we're using purple so you can see it better.
Thread a needle and pass it through a hole on GEMMA.
Tie the thread in a knot around the NeoPixel ring, aligning the thread between pixels. Do this in four spots around GEMMA to secure it in the center of the earring.
You can either glue a pendant hanger on the back with E6000 adhesive (hot glue is INSUFFICIENT), or attach an ear wire with a jump ring and two pairs of pliers.
Our tiny lipoly battery can be affixed to the back with double-stick tape. Secure it further with more clear thread if desired.
# GEMMA Hoop Earrings
## Wear 'em!
Enjoy your precious jewels! Each circuit weighs a measly 11.39 grams! Keep them out of the rain, and switch off when not in use.
The first version of the GEMMA board did not include a power switch — if using one of these, you’ll need to unplug the battery to switch the circuit off.
## Featured Products
### Adafruit GEMMA v2 - Miniature wearable electronic platform
[Adafruit GEMMA v2 - Miniature wearable electronic platform](https://www.adafruit.com/product/1222)
**Deprecation Warning: The Gemma bit-bang USB technique it uses doesn't work as well as it did in 2014, many modern computers won't work well. So while we still carry the Gemma so that people can maintain some older projects, we no longer recommend it.**
In Stock
[Buy Now](https://www.adafruit.com/product/1222)
[Related Guides to the Product](https://learn.adafruit.com/products/1222/guides)
### Adafruit GEMMA M0 - Miniature wearable electronic platform
[Adafruit GEMMA M0 - Miniature wearable electronic platform](https://www.adafruit.com/product/3501)
The **Adafruit Gemma M0** is a super small microcontroller board, with just enough built-in to create many simple projects. It may look small and cute: round, about the size of a quarter, with friendly alligator-clip sew pads. But do not be fooled! The Gemma M0 is incredibly...
In Stock
[Buy Now](https://www.adafruit.com/product/3501)
[Related Guides to the Product](https://learn.adafruit.com/products/3501/guides)
### NeoPixel Ring - 16 x 5050 RGB LED with Integrated Drivers
[NeoPixel Ring - 16 x 5050 RGB LED with Integrated Drivers](https://www.adafruit.com/product/1463)
Round and round and round they go! 16 ultra bright smart LED NeoPixels are arranged in a circle with 1.75" (44.5mm) outer diameter. The rings are 'chainable' - connect the output pin of one to the input pin of another. Use only one microcontroller pin to control as many as you can...
Out of Stock
[Buy Now](https://www.adafruit.com/product/1463)
[Related Guides to the Product](https://learn.adafruit.com/products/1463/guides)
### Lithium Ion Polymer Battery - 3.7v 150mAh
[Lithium Ion Polymer Battery - 3.7v 150mAh](https://www.adafruit.com/product/1317)
Lithium-ion polymer (also known as 'lipo' or 'lipoly') batteries are thin, light, and powerful. The output ranges from 4.2V when completely charged to 3.7V. This battery has a capacity of 150mAh for a total of about 0.6 Wh. If you need a larger battery,
Out of Stock
[Buy Now](https://www.adafruit.com/product/1317)
[Related Guides to the Product](https://learn.adafruit.com/products/1317/guides)
### Adafruit Micro Lipo - USB LiIon/LiPoly charger
[Adafruit Micro Lipo - USB LiIon/LiPoly charger](https://www.adafruit.com/product/1304)
Oh so adorable, this is the tiniest little lipo charger, so handy you can keep it any project box! Its also easy to use. Simply plug in the gold plated contacts into any USB port and a 3.7V/4.2V lithium polymer or lithium ion rechargeable battery into the JST plug on the other end. There are...
In Stock
[Buy Now](https://www.adafruit.com/product/1304)
[Related Guides to the Product](https://learn.adafruit.com/products/1304/guides)
### Gemma M0 Starter Pack
[Gemma M0 Starter Pack](https://www.adafruit.com/product/1657)
Get started with Adafruit GEMMA with this lovely starter kit! Included is everything you need to make a basic project. There's a GEMMA M0, four sewable bright RGB pixels, a battery holder (coin cell batteries not included), 2-ply conductive thread, alligator clips to help you test...
In Stock
[Buy Now](https://www.adafruit.com/product/1657)
[Related Guides to the Product](https://learn.adafruit.com/products/1657/guides)
### Adafruit Gemma Sensor Starter Pack
[Adafruit Gemma Sensor Starter Pack](https://www.adafruit.com/product/1849)
Go interactive with sensors and Adafruit GEMMA with this lovely starter kit! Included is everything you need to make a basic sensing project (or two). There's a GEMMA board, four sewable bright RGB pixels, a motion sensor, a switch, a light sensor, a piezo, a rechargeable battery and...
In Stock
[Buy Now](https://www.adafruit.com/product/1849)
[Related Guides to the Product](https://learn.adafruit.com/products/1849/guides)
### Adafruit Gemma Sequin Starter Pack
[Adafruit Gemma Sequin Starter Pack](https://www.adafruit.com/product/1850)
Make your wearables glow with the **GEMMA sequin pack**! This GEMMA parts pack makes it easy to add light to your wearables. It comes with thread, needles, a holder for 2 x CR2032 coin cell batteries, a GEMMA sewable microcontroller, and warm white Adafruit LED Sequins. This pack...
Out of Stock
[Buy Now](https://www.adafruit.com/product/1850)
[Related Guides to the Product](https://learn.adafruit.com/products/1850/guides)
## Related Guides
- [Neopixel Jewel 10 Minute Necklace](https://learn.adafruit.com/10-minute-neopixel-necklace.md)
- [Hidden Ink UV Message Reader](https://learn.adafruit.com/hidden-ink-uv-message-reader.md)
- [NeoPixel Basketball Hoop](https://learn.adafruit.com/neopixel-mini-basketball-hoop.md)
- [Glowing Fascinator Hat with Gemma M0 and MakeCode](https://learn.adafruit.com/glowing-fascinator-hat-gemma-m0-makecode.md)
- [Techno-Tiki RGB LED Torch](https://learn.adafruit.com/techno-tiki-rgb-led-torch.md)
- [FLORA and GEMMA ICSP](https://learn.adafruit.com/flora-and-gemma-isp.md)
- [Adafruit Arduino IDE Setup](https://learn.adafruit.com/adafruit-arduino-ide-setup.md)
- [Trinket / Gemma Space Invader Pendant](https://learn.adafruit.com/trinket-slash-gemma-space-invader-pendant.md)
- [CircuitPython Basics: Analog Inputs & Outputs](https://learn.adafruit.com/circuitpython-basics-analog-inputs-and-outputs.md)
- [Han Solo Blaster Cosplay](https://learn.adafruit.com/han-solo-blaster-cosplay.md)
- [3D Printed Unicorn Horn](https://learn.adafruit.com/3d-printed-unicorn-horn.md)
- [3D Printed LED Fire Horns](https://learn.adafruit.com/3d-printed-led-fire-horns.md)
- [3D Printed NeoPixel LED Gas Mask](https://learn.adafruit.com/3d-printed-el-wire-laser-neopixel-led-gas-mask.md)
- [Color Balancing Video Camera Light feat. DotStars](https://learn.adafruit.com/color-balancing-light-box-with-dotstar-cool-warm-white-leds.md)
- [Fitbit Force Teardown](https://learn.adafruit.com/fitbit-force-teardown.md)