Ripple for FastLED Library

// Ripple
//
// Converted (but not optimized) from the Neopixel version https://gist.github.com/suhajdab/9716635
//
// Conversion by Andrew Tuline
//


#include <FastLED.h>        // FastLED library


#define LED_DT 13
#define NUM_LEDS 24

struct CRGB leds[NUM_LEDS];

int color;
int center = 0;
int step = -1;
int maxSteps = 16;
float fadeRate = 0.8;
int diff;

//background color
uint32_t currentBg = random(256);
uint32_t nextBg = currentBg;

void setup() {

  Serial.begin(9600);
  LEDS.addLeds<WS2811, LED_DT, GRB>(leds, NUM_LEDS);

}

void loop () {
  ripple();
}

void ripple() {

    if (currentBg == nextBg) {
      nextBg = random(256);
    }
    else if (nextBg > currentBg) {
      currentBg++;
    } else {
      currentBg--;
    }
    for(uint16_t l = 0; l < NUM_LEDS; l++) {
      leds[l] = CHSV(currentBg, 255, 50);         // strip.setPixelColor(l, Wheel(currentBg, 0.1));
    }

  if (step == -1) {
    center = random(NUM_LEDS);
    color = random(256);
    step = 0;
  }

  if (step == 0) {
    leds[center] = CHSV(color, 255, 255);         // strip.setPixelColor(center, Wheel(color, 1));
    step ++;
  }
  else {
    if (step < maxSteps) {
      Serial.println(pow(fadeRate,step));

      leds[wrap(center + step)] = CHSV(color, 255, pow(fadeRate, step)*255);       //   strip.setPixelColor(wrap(center + step), Wheel(color, pow(fadeRate, step)));
      leds[wrap(center - step)] = CHSV(color, 255, pow(fadeRate, step)*255);       //   strip.setPixelColor(wrap(center - step), Wheel(color, pow(fadeRate, step)));
      if (step > 3) {
        leds[wrap(center + step - 3)] = CHSV(color, 255, pow(fadeRate, step - 2)*255);     //   strip.setPixelColor(wrap(center + step - 3), Wheel(color, pow(fadeRate, step - 2)));
        leds[wrap(center - step + 3)] = CHSV(color, 255, pow(fadeRate, step - 2)*255);     //   strip.setPixelColor(wrap(center - step + 3), Wheel(color, pow(fadeRate, step - 2)));
      }
      step ++;
    }
    else {
      step = -1;
    }
  }

  LEDS.show();
  delay(50);
}


int wrap(int step) {
  if(step < 0) return NUM_LEDS + step;
  if(step > NUM_LEDS - 1) return step - NUM_LEDS;
  return step;
}


void one_color_allHSV(int ahue, int abright) {                // SET ALL LEDS TO ONE COLOR (HSV)
  for (int i = 0 ; i < NUM_LEDS; i++ ) {
    leds[i] = CHSV(ahue, 255, abright);
  }
}



// Input a value 0 to 255 to get a color value.
// The colours are a transition r - g - b - back to r.
/* uint32_t Wheel(byte WheelPos, float opacity) {

  if(WheelPos < 85) {
    return strip.Color((WheelPos * 3) * opacity, (255 - WheelPos * 3) * opacity, 0);
  }
  else if(WheelPos < 170) {
    WheelPos -= 85;
    return strip.Color((255 - WheelPos * 3) * opacity, 0, (WheelPos * 3) * opacity);
  }
  else {
    WheelPos -= 170;
    return strip.Color(0, (WheelPos * 3) * opacity, (255 - WheelPos * 3) * opacity);
  }
}
*/