Add Mic & FLORA

Once your NeoPixels are hooked up nicely, it's time to add the rest of the circuit. If your FLORA is going on the outside of your hat, solder those wires up directly.

If you want to hide FLORA on the inside of your hat, cut a small hole near the NeoPixel strip and slide the wires through before soldering them to FLORA.

Refer to the circuit diagram to be sure you're wiring everything up correctly!
Wrap your battery in gaffers tape to provide a bit of strain relief to the wires and protect it from light wear.

You can hide this battery in the band of the hat, and run the wire to the outside (if that's where your FLORA is), or along the inside of the band to FLORA.

Test that your NeoPixel sample code is still working on battery power and now that you've soldered FLORA.
To add the microphone, first prep a three-channel ribbon wire (or three pieces of plain stranded wire) by stripping and tinning the ends.

Set up the wire and the mic in a third hand tool to make it easier to solder the wires to the holes on the breakout board. Trim the excess wire short with flush diagonal cutters.

On the outside, it's easy to just solder the wires according to the circuit diagram and stitch the mic down.
If you want to hide the mic inside the hat, mark where you'd like it to go with a pencil.

Carefully trim a mic-sized circle at the mark using very sharp scissors.

Optional step! If your hat is mostly synthetic (acrylic/polyester), you can singe the edge of the cut hole with a lighter to make it tidier. This hat is part wool, so doing this smells like burned hair. Hey, it's optional!
Arrange FLORA and the mic board inside the hat as you'd like them, then solder the connections to the mic according to the circuit diagram.
Then stitch the FLORA and mic board to the inside of the hat.

Plug FLORA in via USB (make sure the battery switch is OFF) and load with the following sound-sensitive code (very barely modified from the Ampli-Tie sketch):

Download: file
LED VU meter for Arduino and Adafruit NeoPixel LEDs.

Hardware requirements:
 - Most Arduino or Arduino-compatible boards (ATmega 328P or better).
 - Adafruit Electret Microphone Amplifier (ID: 1063)
 - Adafruit Flora RGB Smart Pixels (ID: 1260)
 - Adafruit NeoPixel Digital LED strip (ID: 1138)
 - Optional: battery for portable use (else power through USB or adapter)
Software requirements:
 - Adafruit NeoPixel library

 - 3.3V to mic amp +
 - GND to mic amp -
 - Analog pin to microphone output (configurable below)
 - Digital pin to LED data input (configurable below)
 See notes in setup() regarding 5V vs. 3.3V boards - there may be an
 extra connection to make and one line of code to enable or disable.

Written by Adafruit Industries.  Distributed under the BSD license.
This paragraph must be included in any redistribution.

#include <Adafruit_NeoPixel.h>

#define N_PIXELS  76  // Number of pixels in strand
#define MIC_PIN   A9  // Microphone is attached to this analog pin
#define LED_PIN    6  // NeoPixel LED strand is connected to this pin
#define NOISE     10  // Noise/hum/interference in mic signal
#define TOP       (N_PIXELS + 2) // Allow dot to go slightly off scale
#define PEAK_FALL 4  // Rate of peak falling dot

  peak      = 0,      // Used for falling dot
  dotCount  = 0,      // Frame counter for delaying dot-falling speed
  volCount  = 0;      // Frame counter for storing past volume data
  vol[SAMPLES],       // Collection of prior volume samples
  lvl       = 10,      // Current "dampened" audio level
  minLvlAvg = 0,      // For dynamic adjustment of graph low & high
  maxLvlAvg = 512;

void setup() {

  // This is only needed on 5V Arduinos (Uno, Leonardo, etc.).
  // Connect 3.3V to mic AND TO AREF ON ARDUINO and enable this
  // line.  Audio samples are 'cleaner' at 3.3V.
//  analogReference(EXTERNAL);

  memset(vol, 0, sizeof(vol));

void loop() {
  uint8_t  i;
  uint16_t minLvl, maxLvl;
  int      n, height;


  n   = analogRead(MIC_PIN);                        // Raw reading from mic 
  n   = abs(n - 512 - DC_OFFSET); // Center on zero
  n   = (n <= NOISE) ? 0 : (n - NOISE);             // Remove noise/hum
  lvl = ((lvl * 7) + n) >> 3;    // "Dampened" reading (else looks twitchy)

  // Calculate bar height based on dynamic min/max levels (fixed point):
  height = TOP * (lvl - minLvlAvg) / (long)(maxLvlAvg - minLvlAvg);

  if(height < 0L)       height = 0;      // Clip output
  else if(height > TOP) height = TOP;
  if(height > peak)     peak   = height; // Keep 'peak' dot at top

  // Color pixels based on rainbow gradient
  for(i=0; i<N_PIXELS; i++) {
    if(i >= height)               strip.setPixelColor(i,   0,   0, 0);
    else strip.setPixelColor(i,Wheel(map(i,0,strip.numPixels()-1,30,150)));

  // Draw peak dot  
  if(peak > 0 && peak <= N_PIXELS-1) strip.setPixelColor(peak,Wheel(map(peak,0,strip.numPixels()-1,30,150)));; // Update strip

// Every few frames, make the peak pixel drop by 1:

    if(++dotCount >= PEAK_FALL) { //fall rate 
      if(peak > 0) peak--;
      dotCount = 0;

  vol[volCount] = n;                      // Save sample for dynamic leveling
  if(++volCount >= SAMPLES) volCount = 0; // Advance/rollover sample counter

  // Get volume range of prior frames
  minLvl = maxLvl = vol[0];
  for(i=1; i<SAMPLES; i++) {
    if(vol[i] < minLvl)      minLvl = vol[i];
    else if(vol[i] > maxLvl) maxLvl = vol[i];
  // minLvl and maxLvl indicate the volume range over prior frames, used
  // for vertically scaling the output graph (so it looks interesting
  // regardless of volume level).  If they're too close together though
  // (e.g. at very low volume levels) the graph becomes super coarse
  // and 'jumpy' keep some minimum distance between them (this
  // also lets the graph go to zero when no sound is playing):
  if((maxLvl - minLvl) < TOP) maxLvl = minLvl + TOP;
  minLvlAvg = (minLvlAvg * 63 + minLvl) >> 6; // Dampen min/max levels
  maxLvlAvg = (maxLvlAvg * 63 + maxLvl) >> 6; // (fake rolling average)


// The colors are a transition r - g - b - back to r.
uint32_t Wheel(byte WheelPos) {
  if(WheelPos < 85) {
  } else if(WheelPos < 170) {
   WheelPos -= 85;
  } else {
   WheelPos -= 170;
This guide was first published on Jun 11, 2014. It was last updated on Jun 11, 2014. This page (Add Mic & FLORA) was last updated on Nov 13, 2019.