1.流动彩虹

void rainbow(int wait) {

  for(long firstPixelHue = 0; firstPixelHue < 3*65536; firstPixelHue += 256) {

    for(int i=0; i<strip.numPixels(); i++) {

      int pixelHue = firstPixelHue + (i * 65536L / strip.numPixels());

      strip.setPixelColor(i, strip.gamma32(strip.ColorHSV(pixelHue)));

    }

    strip.show(); // Update strip with new contents

    delay(wait);  // Pause for a moment

  }

}