#include <Adafruit_NeoPixel.h>

#define LED_PIN     6
#define LED_COUNT  160

Adafruit_NeoPixel strip(LED_COUNT, LED_PIN, NEO_GRB + NEO_KHZ800);

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

void loop() {
  rainbow(20); // delay between color transitions (ms)
}

void rainbow(uint8_t wait) {
  uint16_t i, j;

  for(j=0; j<256; j++) {
    for(i=0; i<strip.numPixels(); i++) {
      strip.setPixelColor(i, Wheel((i+j) & 255, true)); // true means only use green
    }
    strip.show();
    delay(wait);
  }
}

uint32_t Wheel(byte WheelPos, bool greenOnly) {
  byte r, g, b;
  if (WheelPos < 85) {
    g = WheelPos * 3;
    r = 0;
    b = 0;
  } else if (WheelPos < 170) {
    if (greenOnly) {
      g = WheelPos * 3;
      r = 0;
      b = 0;
    } else {
      WheelPos -= 85;
      r = WheelPos * 3;
      g = 255 - r;
      b = 0;
    }
  } else {
    if (greenOnly) {
      g = (255 - WheelPos) * 3;
      r = 0;
      b = 0;
    } else {
      WheelPos -= 170;
      b = WheelPos * 3;
      g = 255 - b;
      r = 0;
    }
  }
  return strip.Color(r,g,b);
}