LED strip group

// LED strip group

#include "FastLED.h"
#define NUM_LEDS 39 // Number of LEDs
#define COLOR_ORDER RGB  // Define color order for your strip
#define DATA_PIN 6  // Data pin for led comunication



CRGB leds[NUM_LEDS]; // Define LEDs strip

uint32_t ledColor = 0x0FF000; // Color used (in hex)
uint32_t ledOff = 0x000000; // LED "off" color used (in hex)


void setup() {

  LEDS.addLeds<WS2812, DATA_PIN, COLOR_ORDER>(leds, NUM_LEDS); // Set LED strip type
  LEDS.setBrightness(64); // Set initial brightness

}

void loop(){

  // One at a time
  for (byte b=0;b<9;b++){

    //set LEDs
    groupout(b,ledColor);

     FastLED.show(); // Display leds array
     delay(800);// wait a bit

     // blank the same ones
    groupout(b,ledOff);
  }

// all on
    for (byte b=0;b<9;b++){
    groupout(b,ledColor);
  }
     FastLED.show(); // Display leds array
     delay(800);// you get the drill

   for (byte b=0;b<9;b++){
    groupout(b,ledOff);
  }

}

// set group of 4 LEDs
void groupout(byte position,uint32_t color) {

  for (byte i = 0; i < 4; i++) {
   leds[(4*position)+i] = color;
  }// close for i loop
}