I made these sound sensitive earrings as something blinky to wear while volunteering at the New York City Girls Computer Science and Engineering Conference. These earrings are a fun example of something interesting you can make with some basic computer science and electronics skills. This project is a mash-up of two Adafruit projects: the Gemma hoop earrings and the LED Ampli-Tie. They can easily be assembled in a few hours.
To start, you will need two Gemma microcontrollers, two NeoPixel 16 pixel rings, two microphones, two small rechargeable batteries, some wire, some jewelry findings, double stick tape, electrical tape and soldering tools. Make sure that you also have a charger for the rechargeable batteries. It’s also a good idea to paint the front of the microphone board black so that it blends in better with the electronics.
These earrings are assembled similarly to the Gemma hoop earrings with the additional step of attaching the microphone. First, start by attaching the LED ring to the Gemma. Connect the IN pin on the LED ring to the Gemma’s D0 pin and connect the LED ring’s V+ and G pins to their respective 3Vo and Gnd pins on the Gemma. Next, attach the microphone. It’s a good idea to place black electrical tape on the back of the microphone board before assembly to help prevent any shorts. Connect the microphone’s OUT pin to the Gemma’s D2 pin and connect the microphone’s VCC and GND pins to their respective 3Vo and Gnd pins on the Gemma. Be sure to run the microphone’s GND wire under the microphone so that the wire is concealed. Solder everything in place.Once the earrings are soldered together, it’s time to program them! I used a modified version of the Ampli-Tie sketch (available on the Adafruit site). I made a few minor modifications, such as changing the pins, removing the tracer dot, and adding a reverse mode so that the earrings can light up in opposite directions.
Next, attach the battery to the back of the Gemma with double stick tape. I also used a permanent marker to color the red battery wires black. Black electrical tape can be used to secure the battery and battery wires to the back of the LED ring and microcontroller.
Finally, attach the earring hooks to the LED ring. I simply attached small O-rings to the OUT pin of the LED ring and then attached the earring hooks with another small O-ring. And that’s it – turn on the Gemma and you are good to go! I found that my 150 mAh battery lasts for about four hours 🙂