//This sketch fades all LEDS in and out and changes colors after each cycle
//This was used for the Christmas star Dec 2018

#include "FastLED.h"

#define NUM_LEDS 50        //How many leds in your strip?
#define DATA_PIN 5         //Arduino board pin used for led strip data

CRGB leds[NUM_LEDS];      // Define the array of leds

int howBright, clr;      // Declare variables: howBright determines LED brightness, clr determines LED color
bool up;                 //A bool(ean) variable can only be true or false

void setup() { 
  LEDS.addLeds<WS2811,DATA_PIN,RGB>(leds,NUM_LEDS);  //Set up the LED string
  howBright=2;                                       //Initialize the howBright variable
  fill_solid( leds, NUM_LEDS, CRGB:: DarkKhaki );   //Begin with all LEDs set to an off white color
  up = true;                                        // When up is true, LEDs get brighter, otherwise they get dimmer
  clr=0;                                            //Initialize the clr variable
}

void loop() {                         //This is the main program loop

  LEDS.setBrightness (howBright);     //Set LED brightness value passed from the goUp and goDown subroutines
  FastLED.show();                     //Show the LEDS
  delay (100);                        //Delay 100 msec (0.1 sec)
  if (up) { goUp(); }                 //If up varialbe is true, call the goUp subroutine
  else { goDown(); }                  //Otherwise, call the goDown subroutine
 
} //====================== END void loop =================================

//This subroutine makes the LEDs get brighter
void goUp() {
  howBright = howBright +1;
  if (howBright >= 36) {      //Max brightness is 36, so if value is reached, change the value of the up variable
    up = !up;
   }
}

// This subroutine makes the LEDs get dimmer
void goDown() {
  howBright = howBright - 1;
  if (howBright == 0) {       //If brightness = zero, it's time to switch colors
    FastLED.clear();          //Turn all the LEDs off
    FastLED.show();           //Show the LEDS
    delay (300);  
    if (clr==0){fill_solid(leds, NUM_LEDS, CRGB:: DarkKhaki    );}          //Choose the next color based on the
      else if (clr==1) {fill_solid(leds, NUM_LEDS, CRGB:: Blue );}          //value of the clr variable
      else if (clr==2) {fill_solid(leds, NUM_LEDS, CRGB:: DarkGoldenrod );}
      else {fill_solid(leds, NUM_LEDS, CRGB:: Red );}
      up = !up;                                             //Change value of the up variable
      clr=clr+1;                                            //Increment the clr variable to change the color
      if (clr > 3){clr=0;}                                  //If clr is > 3, go back to zero
  }
}