#include <FastLED.h>
//https://github.com/FastLED/FastLED/wiki/Controlling-leds
#define NUM_LEDS  12
#define LED_PIN   3

CRGB leds[NUM_LEDS];

void setup() {
  FastLED.addLeds<WS2812B, LED_PIN, GRB>(leds, NUM_LEDS);
  FastLED.setBrightness(255);
  
  leds[0].red = leds[0].green = leds[0].blue = 255;
  FastLED.show();
  delay(2500);

  Serial.begin(115200); Serial.println("Start"); 
  leds[0] = leds[3] = leds[6] = leds[9] = CRGB::Red;
  FastLED.show();
  delay(500);
  
  leds[1] = leds[4] = leds[7] = leds[10] = CRGB::Green;
  FastLED.show();
  delay(500);

  leds[2] = leds[5] = leds[8] = leds[11]  = CRGB::Blue;
  FastLED.show();
  delay(500);
}

int dt=50;
byte rot = 128; byte gruen = 64; byte blau = 160;	
void loop() {
  for (byte nr=0; nr<NUM_LEDS; nr++) {	
    leds[nr].setRGB(rot, gruen, blau);
    FastLED.show();
    delay(dt);
    rot = rot + 32;
    gruen = gruen + 32;
    blau=blau+16; 
	}
  String txt = String(rot) + " " +String(gruen) + " " + String(blau);
  Serial.println(txt); 
}