#include <FastLED.h>

#define BRIGHTNESS    64
#define NUM_LEDS      32
#define LED_PIN       5
#define CHIPSET       WS2812B
#define COLOR_ORDER   GRB


CRGB leds[NUM_LEDS];

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


int offset = 0;

void loop() {
  for(int i = 0; i < NUM_LEDS; ++i) {
    leds[i%NUM_LEDS] = ColorFromPalette(RainbowColors_p, (i + offset) * 255 / NUM_LEDS % 255);
  }

  offset++;
  offset %= NUM_LEDS;

  FastLED.show(); 
  delay(30); 
}