sketch aurora borealis

#include "FastLED.h"


#if FASTLED_VERSION < 3001000
#error "Requires FastLED 3.1 or later; check github for latest code."
#endif

#define DATA_PIN    3
//#define CLK_PIN   4
#define LED_TYPE    WS2811
#define COLOR_ORDER GRB
#define NUM_LEDS    9

#define BRIGHTNESS  255

CRGB leds[NUM_LEDS];

// ten seconds per color palette makes a good demo
// 20-120 is better for deployment
#define SECONDS_PER_PALETTE 33






void setup() {
  delay(9000); // 3 second delay for recovery

  // tell FastLED about the LED strip configuration
  FastLED.addLeds<LED_TYPE,DATA_PIN,COLOR_ORDER>(leds, NUM_LEDS)
    //.setCorrection(TypicalLEDStrip) // cpt-city palettes have different color balance
    .setDither(BRIGHTNESS < 255);

  // set master brightness control
  FastLED.setBrightness(BRIGHTNESS);
}






// Forward declarations of an array of cpt-city gradient palettes, and
// a count of how many there are.  The actual color palette definitions
// are at the bottom of this file.
extern const TProgmemRGBGradientPalettePtr gGradientPalettes[];
extern const uint8_t gGradientPaletteCount;

// Current palette number from the 'playlist' of color palettes
uint8_t gCurrentPaletteNumber = 0;

CRGBPalette16 gCurrentPalette( CRGB::Black);
CRGBPalette16 gTargetPalette( gGradientPalettes[0] );









void loop()
{
  EVERY_N_SECONDS( SECONDS_PER_PALETTE ) {
    gCurrentPaletteNumber = addmod8( gCurrentPaletteNumber, 1, gGradientPaletteCount);
    gTargetPalette = gGradientPalettes[ gCurrentPaletteNumber ];
  }

  EVERY_N_MILLISECONDS(40) {
    nblendPaletteTowardPalette( gCurrentPalette, gTargetPalette, 16);
  }

  colorwaves( leds, NUM_LEDS, gCurrentPalette);

  FastLED.show();
  FastLED.delay(20);
}




// This function draws color waves with an ever-changing,
// widely-varying set of parameters, using a color palette.
void colorwaves( CRGB* ledarray, uint16_t numleds, CRGBPalette16& palette)
{
  static uint16_t sPseudotime = 0;
  static uint16_t sLastMillis = 0;
  static uint16_t sHue16 = 0;

  uint8_t sat8 = beatsin88( 87, 220, 250);
  uint8_t brightdepth = beatsin88( 341, 96, 224);
  uint16_t brightnessthetainc16 = beatsin88( 203, (25 * 256), (40 * 256));
  uint8_t msmultiplier = beatsin88(147, 23, 60);

  uint16_t hue16 = sHue16;//gHue * 256;
  uint16_t hueinc16 = beatsin88(113, 300, 1500);

  uint16_t ms = millis();
  uint16_t deltams = ms - sLastMillis ;
  sLastMillis  = ms;
  sPseudotime += deltams * msmultiplier;
  sHue16 += deltams * beatsin88( 400, 5,9);
  uint16_t brightnesstheta16 = sPseudotime;

  for( uint16_t i = 0 ; i < numleds; i++) {
    hue16 += hueinc16;
    uint8_t hue8 = hue16 / 256;
    uint16_t h16_128 = hue16 >> 7;
    if( h16_128 & 0x100) {
      hue8 = 255 - (h16_128 >> 1);
    } else {
      hue8 = h16_128 >> 1;
    }

    brightnesstheta16  += brightnessthetainc16;
    uint16_t b16 = sin16( brightnesstheta16  ) + 32768;

    uint16_t bri16 = (uint32_t)((uint32_t)b16 * (uint32_t)b16) / 65536;
    uint8_t bri8 = (uint32_t)(((uint32_t)bri16) * brightdepth) / 65536;
    bri8 += (255 - brightdepth);

    uint8_t index = hue8;
    //index = triwave8( index);
    index = scale8( index, 240);

    CRGB newcolor = ColorFromPalette( palette, index, bri8);

    uint16_t pixelnumber = i;
    pixelnumber = (numleds-1) - pixelnumber;

    nblend( ledarray[pixelnumber], newcolor, 128);
  }
}



// Alternate rendering function just scrolls the current palette
// across the defined LED strip.
void palettetest( CRGB* ledarray, uint16_t numleds, const CRGBPalette16& gCurrentPalette)
{
  static uint8_t startindex = 0;
  startindex--;
  fill_palette( ledarray, numleds, startindex, (256 / NUM_LEDS) + 1, gCurrentPalette, 255, LINEARBLEND);
}

// erst ab hier die palette knife ???   //


// Gradient Color Palette definitions for 33 different cpt-city color palettes.
//    956 bytes of PROGMEM for all of the palettes together,
//   +618 bytes of PROGMEM for gradient palette code (AVR).
//  1,494 bytes total for all 34 color palettes and associated code.


// Gradient palette "bar_sinestre_gp", originally from
// http://soliton.vm.bytemark.co.uk/pub/cpt-city/pj/1/tn/bar-sinestre.png.index.html
// converted for FastLED with gammas (2.6, 2.2, 2.5)
// Size: 60 bytes of program space.

DEFINE_GRADIENT_PALETTE( bar_sinestre_gp ) {
    0,  46, 37,  5,
    0,  46, 37,  5,
   12,  27, 26,  3,
   30,   1,  8,  4,
   43,   1, 15,  9,
   73,   7, 68, 29,
   94,  22, 87, 15,
  119,   1, 37, 29,
  137,   1, 50, 62,
  163,   4, 68,153,
  181,   4, 68,153,
  198,   1, 29, 34,
  224,  18, 45,  5,
  237,   1, 17, 19,
  255,  46, 37,  5};



// This list of color palettes acts as a "playlist"; you can
// add or delete, or re-arrange as you wish.
const TProgmemRGBGradientPalettePtr gGradientPalettes[] = {
bar_sinestre_gp,
   };

// Count of how many cpt-city gradients are defined:
const uint8_t gGradientPaletteCount =
  sizeof( gGradientPalettes) / sizeof( TProgmemRGBGradientPalettePtr );