Double check that all your conductive thread tails have been trimmed and your skirt is laying flat on a nonconductive surface, and then connect your FLORA main board to your computer with a USB cable.

Open the Adafruit Arduino IDE, which you can download from the Getting Started with FLORA guide.

You will need the NeoPixel library for this project-- if you've never installed an Arduino library before, read our guide on the topic!

Open up the Library manager

Find the Adafruit NeoPixel library and install it...

First test out all six pixels by uploading the sketch in File >> Examples >> Adafruit_NeoPixel >> strandtest.

If all of your pixels light up and change color, you're good to continue to the back! Disconnect the USB cable before stitching more pixels on the back. For more tips on stitching up a line of NeoPixels, read the corresponding page in our LED Ampli-Tie guide.

When you have pixels on the front and back of the skirt, place a piece of scrap fabric in between them for testing (so they don't short each other out), or put the skirt on a dress form. When you're wearing the skirt, your body will keep the front and back from touching.

If your skirt has lots of folds, you may have trouble with your pixel connections shorting against each other. You can insulate them under a piece of ribbon, wear a slip under the skirt, and also add some wobble to your pixel line so when the skirt folds, traces aren't up against each other.

Next test out the accelerometer, install the Adafruit LSM303DLHC library using the library manager. Make sure you grab the one with DLHC in the name

Also, install the Adafruit Unified Sensor library

Now test by uploading the sketch in File >> Examples >> Adafruit_LSM303 >> Accel_Sensor.

Open up the serial monitor and watch for changing motion values. For more information, check out our FLORA Accelerometer guide.

Click the Download File button below to get the code.

The colors can be specified in the myFavoriteColors array, and the sensitivity to motion can be defined with MOVE_THRESHOLD.

// SPDX-FileCopyrightText: 2017 Limor Fried for Adafruit Industries
// SPDX-License-Identifier: MIT

#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_LSM303DLH_Mag.h>
#include <Adafruit_NeoPixel.h>

// Parameter 1 = number of pixels in strip
// Parameter 2 = pin number (most are valid)
// Parameter 3 = pixel type flags, add together as needed:
//   NEO_RGB     Pixels are wired for RGB bitstream
//   NEO_GRB     Pixels are wired for GRB bitstream
//   NEO_KHZ400  400 KHz bitstream (e.g. FLORA pixels)
//   NEO_KHZ800  800 KHz bitstream (e.g. High Density LED strip)
Adafruit_NeoPixel strip = Adafruit_NeoPixel(6, 6, NEO_GRB + NEO_KHZ800);
Adafruit_LSM303DLH_Mag_Unified accel = Adafruit_LSM303DLH_Mag_Unified(54321);

// Here is where you can put in your favorite colors that will appear!
// just add new {nnn, nnn, nnn}, lines. They will be picked out randomly
//                                  R   G   B
uint8_t myFavoriteColors[][3] = {{200,   0, 200},   // purple
                                 {200,   0,   0},   // red 
                                 {200, 200, 200},   // white
// don't edit the line below
#define FAVCOLORS sizeof(myFavoriteColors) / 3

// mess with this number to adjust TWINklitude :)
// lower number = more sensitive

void setup() 
  // Try to initialise and warn if we couldn't detect the chip
  if (!accel.begin())
    Serial.println("Oops ... unable to initialize the LSM303. Check your wiring!");
    while (1);
  strip.begin();; // Initialize all pixels to 'off'

void loop() 
  /* Get a new sensor event */ 
  sensors_event_t event; 
  Serial.print("Accel X: "); Serial.print(event.acceleration.x); Serial.print(" ");
  Serial.print("Y: "); Serial.print(event.acceleration.y);       Serial.print(" ");
  Serial.print("Z: "); Serial.print(event.acceleration.z);     Serial.print(" ");

  // Get the magnitude (length) of the 3 axis vector
  double storedVector = event.acceleration.x*event.acceleration.x;
  storedVector += event.acceleration.y*event.acceleration.y;
  storedVector += event.acceleration.z*event.acceleration.z;
  storedVector = sqrt(storedVector);
  Serial.print("Len: "); Serial.println(storedVector);
  // wait a bit
  // get new data!
  double newVector = event.acceleration.x*event.acceleration.x;
  newVector += event.acceleration.y*event.acceleration.y;
  newVector += event.acceleration.z*event.acceleration.z;
  newVector = sqrt(newVector);
  Serial.print("New Len: "); Serial.println(newVector);
  // are we moving 
  if (abs(newVector - storedVector) > MOVE_THRESHOLD) {
    flashRandom(5, 1);  // first number is 'wait' delay, shorter num == shorter twinkle
    flashRandom(5, 3);  // second number is how many neopixels to simultaneously light up
    flashRandom(5, 2);

void flashRandom(int wait, uint8_t howmany) {

  for(uint16_t i=0; i<howmany; i++) {
    // pick a random favorite color!
    int c = random(FAVCOLORS);
    int red = myFavoriteColors[c][0];
    int green = myFavoriteColors[c][1];
    int blue = myFavoriteColors[c][2]; 

    // get a random pixel from the list
    int j = random(strip.numPixels());
    //Serial.print("Lighting up "); Serial.println(j); 
    // now we will 'fade' it in 5 steps
    for (int x=0; x < 5; x++) {
      int r = red * (x+1); r /= 5;
      int g = green * (x+1); g /= 5;
      int b = blue * (x+1); b /= 5;
      strip.setPixelColor(j, strip.Color(r, g, b));;
    // & fade out in 5 steps
    for (int x=5; x >= 0; x--) {
      int r = red * x; r /= 5;
      int g = green * x; g /= 5;
      int b = blue * x; b /= 5;
      strip.setPixelColor(j, strip.Color(r, g, b));;
  // LEDs will be off when done (they are faded to 0)
Use a scrap piece of coordinating fabric to sew a small battery pouch. We doubled ours over, used the sewing machine to stitch in an L, then clipped the corner and turned the pouch right-side out.

Stitch the battery pouch to the skirt lining with regular thread in a place nearby the FLORA main board.

This guide was first published on Apr 24, 2013. It was last updated on Nov 15, 2023.

This page (Code & Battery) was last updated on Nov 15, 2023.

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