#include <FastLED.h>

#define NUM_LEDS 16
#define DATA_PIN 1

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

void setup() {
	LEDS.addLeds<WS2812,DATA_PIN,RGB>(leds,NUM_LEDS);
	LEDS.setBrightness(255);
}

void fadeall() { for(int i = 0; i < NUM_LEDS; i++) { leds[i].nscale8(250); } }

void loop() {
	static uint8_t hue = 0;
	// First slide the led in one direction
	for(int i = 0; i < NUM_LEDS; i++) {
		// Set the i'th led to red
		leds[i] = CHSV(hue++, 255, 255);
		// Show the leds
		FastLED.show();
		// now that we've shown the leds, reset the i'th led to black
		// leds[i] = CRGB::Black;
		fadeall();
		// Wait a little bit before we loop around and do it again
		delay(40);
	}

	// Now go in the other direction.
	for(int i = (NUM_LEDS)-1; i >= 0; i--) {
		// Set the i'th led to red
		leds[i] = CHSV(hue++, 255, 255);
		// Show the leds
		FastLED.show();
		// now that we've shown the leds, reset the i'th led to black
		// leds[i] = CRGB::Black;
		fadeall();
		// Wait a little bit before we loop around and do it again
		delay(40);
	}
}