#include <Arduino.h>
#include <FastLED.h>

#define LED_PIN     11
#define COLOR_ORDER GRB
#define CHIPSET     WS2811
#define NUM_LEDS    1

CRGB leds[NUM_LEDS];

void setup() 
{
  FastLED.addLeds<CHIPSET, LED_PIN, COLOR_ORDER>(leds, NUM_LEDS).setCorrection( TypicalLEDStrip );
}

uint8_t i=0;
uint8_t upp=1;
void loop() 
{
  if (upp)
  {
    if (i<255)
    {
      i++;
    }
    else
    {
      upp = 0;
    }
  }
  else
  {
    if (i>0)
    {
      i--;
    }
    else
    {
      upp = 1;
    }
  }
  
  leds[0].r = i; 
  leds[0].g = i; 
  leds[0].b = i; 
  FastLED.show(); 
  delay(4);
}