#include "neopixel.h"
// IMPORTANT: Set pixel COUNT, PIN and TYPE
#define PIXEL_PIN D2
#define PIXEL_COUNT 16
#define PIXEL_TYPE WS2812

Adafruit_NeoPixel strip = Adafruit_NeoPixel(PIXEL_COUNT, PIXEL_PIN, PIXEL_TYPE);

void setup() {
    
    strip.begin();
    strip.show(); // Initialize all pixels to 'off'
}

void loop() {
    
    // here is to light up the pixel one by one
    
    uint16_t i;
    uint32_t c = strip.Color(0, 0, 255); //blue

    for(i=0; i < strip.numPixels(); i++) {
        strip.setPixelColor(i, c );
		strip.show();
		delay( 100 );
    }
	
	delay( 100 );
	
	// here is to turn off the pixel one by one
	
	for(i=strip.numPixels(); i > 0; i--) {
        strip.setPixelColor(i, 0 );
		strip.show();
		delay( 100 );
    }

	delay( 100 );

}