#include <FastLED.h>

// Move a white dot along the strip of leds.  This program simply shows how to configure the leds,
// and then how to turn a single pixel white and then off, moving down the line of pixels.
#define NUM_LEDS 300

#define DATA_PIN 5

// This is an array of leds.  One item for each led in your strip.
CRGB leds[NUM_LEDS];

void setup() {
    delay(2000);
    FastLED.addLeds<WS2812B, DATA_PIN, RGB>(leds, NUM_LEDS);  // GRB ordering is typical

void loop() {
   // Move a single white led
   for(int whiteLed = 0; whiteLed < NUM_LEDS; whiteLed = whiteLed + 1) {
      // Turn our current led on to white, then show the leds
      leds[whiteLed] = CRGB::White;

      // Show the leds (only one of which is set to white, from above)
      FastLED.show();

      // Wait a little bit
      delay(100);

      // Turn our current led back to black for the next loop around
      leds[whiteLed] = CRGB::Black;
   }
}