new fireworks

#include "FastLED.h"

#define stripPin 6
#define LED_TYPE    WS2811
#define COLOR_ORDER GRB
#define stripLength    88
#define BRIGHTNESS  128

byte shell1 = 1;
byte shell2 = 0;
int shell1pos = 0;
int shell2pos = 0;
uint8_t shell1start = random(10,80);
uint8_t shell2start = random(10,80);
uint8_t shell1hue = random(255);
uint8_t shell2hue = random(255);
uint8_t tailLength = 8;

CRGB leds[stripLength];

void setup() {
  Serial.begin(9600);
  randomSeed(analogRead(0));
  delay(3000); // 3 second delay for recovery
  FastLED.setMaxPowerInVoltsAndMilliamps(5, 1500);

  // tell FastLED about the LED strip configurations
  FastLED.addLeds<LED_TYPE, stripPin, COLOR_ORDER>(leds, stripLength);

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

void loop() {
  fireworks();
}

void fireworks(){

  //shell 1
    if(shell1==1){

      //light master shells in opposite directions at position if greater than 0 and less than total length
      if((shell1start+shell1pos)<stripLength) leds[(shell1start+shell1pos)] = CHSV(shell1hue, 255,255);
      if((shell1start-shell1pos)>0) leds[(shell1start-shell1pos)] = CHSV(shell1hue, 255,255);

      //lights secondary shell at halfway point
      int halfWay1 = stripLength-shell1start;
      if((shell1start+shell1pos)>halfWay1) shell2=1;

      //creates tail
      for (int t=1; t<=tailLength; t++){
        int front = shell1start+shell1pos-t;
        int back = shell1start-shell1pos+t;

        //if tail positions would overlap initial start position, don't show
        if(front>shell1start && front<stripLength) leds[front] = CHSV(shell1hue-40,255,random(40));
        if(back<shell1start && back>0) leds[back] = CHSV(shell1hue-40,255,random(40));
      }

      //if shell has reached the end of BOTH sides of strip, reset color and pick new position
      if((shell1start+shell1pos)+tailLength>=stripLength && (shell1start-shell1pos)-tailLength<=0){
        shell1start = random(10,80);
        shell1pos = 0;
        shell1hue = random(255);
        shell1=0;
      }else{
        //increase position
      shell1pos++;
      }
    }

  //shell2
    if(shell2==1){

      //light master shells in opposite directions at position if greater than 0 and less than total length
      if((shell2start+shell2pos)<stripLength) leds[(shell2start+shell2pos)] = CHSV(shell2hue, 255,255);
      if((shell2start-shell2pos)>0) leds[(shell2start-shell2pos)] = CHSV(shell2hue, 255,255);

      //lights secondary shell at halfway point
      int halfWay2 = stripLength-shell2start;
      if((shell2start+shell1pos)>halfWay2) shell1=1;

      //creates tail
      for (int t=1; t<=tailLength; t++){
        int front = shell2start+shell2pos-t;
        int back = shell2start-shell2pos+t;

        //if tail positions would overlap initial start position, don't show
        if(front>shell2start && front<stripLength) leds[front] = CHSV(shell2hue-40,255,random(40));
        if(back<shell2start && back>0) leds[back] = CHSV(shell2hue-40,255,random(40));
      }

      //if shell has reached the end of BOTH sides of strip, reset color and pick new position
      if((shell2start+shell2pos)+tailLength>=stripLength && (shell2start-shell2pos)-tailLength<=0){
        shell2start = random(10,80);
        shell2pos = 0;
        shell2hue = random(255);
        shell2=0;
      }else{
        //increase position
      shell2pos++;
      }
    }

    //display everything
    FastLED.show();
    FastLED.delay(30);

    //reset everything to black to prep for next position
    for(int j=0;j<stripLength;j++){leds[j] = CRGB::Black;}

    //sometimes there's a kink where not enough time is given to reset any given shell. this is a slam fix
    if(shell2==0 && shell1==0)shell1=1;
}