Sew a little sparkle into your wearable project with an Adafruit LED Sequin. These are the kid-sister to our popular Flora NeoPixel-- they only show a single color and they aren't addressable, but they are our smallest sewable LEDs ever and very easy to use!
This guide was written for the 'original' Gemma board, but can be done with either the original or M0 Gemma. We recommend the Gemma M0 as it is easier to use and is more compatible with modern computers!
They come in packs of five with breakaway tabs-- you can separate them one at a time as you build your project.
Simply connect 3 to 6VDC to the + pin and ground to the - pin, and the LED on the board will light up. In the photo above we've soldered alligator clips to a 2x2032 coincell battery holder (~6V). You could also use a single CR2032 sewable coincell holder-- you do not need a microcontroller to drive these sequins, unless you want them to blink or fade.
When powered from 3.3V they draw about 5mA so you can put up to 4 or 5 in parallel on a single microcontroller pin. We currently have these sequins in warm white, emerald green, ruby red, and royal blue.
You can make the LEDs fade and twinkle by using the PWM (a.k.a. analogWrite) functionality of your Gemma or Flora, or just connect directly to a digital I/O pin of a microcontroller to turn on and off (digitalWrite).