#define FASTLED_ALLOW_INTERRUPTS 0
#include <FastLED.h>
FASTLED_USING_NAMESPACE

#define DATA_PIN            3
#define WIDTH               18
#define HEIGHT              7
#define NUM_LEDS            WIDTH * HEIGHT //126
#define MAX_POWER_MILLIAMPS 500
#define LED_TYPE            WS2812B
#define COLOR_ORDER         GRB
#define BRIGHTNESS          255

CRGB leds[NUM_LEDS];

void setup() {
  Serial.begin(9600);

  FastLED.addLeds<LED_TYPE,DATA_PIN,COLOR_ORDER>(leds, NUM_LEDS).setCorrection( TypicalLEDStrip );
  FastLED.setMaxPowerInVoltsAndMilliamps( 5, MAX_POWER_MILLIAMPS);
  FastLED.setBrightness(BRIGHTNESS);
  FastLED.clear();
  FastLED.show();

  leds[0] = CRGB::Red;
  FastLED.show();
}

void loop() {
  EVERY_N_MILLISECONDS(500) {
    Serial.println( "ok" );
    FastLED.show();
  }
}