#include <Adafruit_NeoPixel.h>

#define N_PIXELS  22  // Number of pixels you are using
#define MIC_PIN    1  // Microphone is attached to Trinket GPIO #2/Gemma D2 (A1)
#define LED_PIN    6  // NeoPixel LED strand is connected to GPIO #0 / D0
#define DC_OFFSET  0  // DC offset in mic signal - if unusure, leave 0
#define NOISE     80  // Noise/hum/interference in mic signal
#define SAMPLES   60  // Length of buffer for dynamic level adjustment
#define TOP       (N_PIXELS +1) // Allow dot to go slightly off scale
// Comment out the next line if you do not want brightness control or have a Gemma
#define POT_PIN    1  // if defined, a potentiometer is on GPIO #3 (A3, Trinket only)

byte
  peak      = 0,      // Used for falling dot
  dotCount  = 0,      // Frame counter for delaying dot-falling speed
  volCount  = 0;      // Frame counter for storing past volume data

int
  vol[SAMPLES],       // Collection of prior volume samples
  lvl       = 10,     // Current "dampened" audio level
  minLvlAvg = 0,      // For dynamic adjustment of graph low & high
  maxLvlAvg = 512;

long previousMillis = 0;        // will store last time LED was updated

long interval = 3;           // interval at which to blink in minutes

Adafruit_NeoPixel  strip = Adafruit_NeoPixel(N_PIXELS, LED_PIN, NEO_GRB + NEO_KHZ800);

void setup() {
  memset(vol, 0, sizeof(vol));

  strip.setBrightness(10);
  strip.begin();
  strip.show();

}

void loop()
{
          dropdown(10);
}

void dropdown(uint8_t wait)
{
  long ledcolor=255/(strip.numPixels());

  for (int cnt = 0; cnt<strip.numPixels(); cnt++)
  {
   for (int i=strip.numPixels(); i>=cnt;i--)
      {
       strip.setPixelColor(i, Wheel(((ledcolor)*(cnt)) & 255));
       strip.setPixelColor(i+1, 0);
       strip.show();
       delay(wait);

      }
}
}

// Input a value 0 to 255 to get a color value.
// The colors are a transition r - g - b - back to r.
uint32_t Wheel(byte WheelPos) {
  if(WheelPos < 85) {
   return strip.Color(WheelPos * 3, 255 - WheelPos * 3, 0);
  } else if(WheelPos < 170) {
   WheelPos -= 85;
   return strip.Color(255 - WheelPos * 3, 0, WheelPos * 3);
  } else {
   WheelPos -= 170;
   return strip.Color(0, WheelPos * 3, 255 - WheelPos * 3);
  }
}