#include <FastLED.h>

// How many leds in your strip?
#define NUM_LEDS 25
#define LED_SMOOTHING_DELAY 20  // mS

#define DATA_PIN 5
#define CLOCK_PIN 13

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

void setup() 
{

    FastLED.addLeds<NEOPIXEL, DATA_PIN>(leds, NUM_LEDS);  // GRB ordering is assumed
}


void loop() 
{
  int i;

  // Turn the LED on, then pause
 for (i=0;i<25;i++)
 {
  leds[i] = CRGB::Blue;
  FastLED.show();
  delay(LED_SMOOTHING_DELAY);
 }
  
  for (i=24;i>=0;i--)
 {
  leds[i] = CRGB::Black;
  FastLED.show();
  delay(LED_SMOOTHING_DELAY);
 }


}