#include <Adafruit_NeoPixel.h>

#define PIN      6
#define N_LEDS 9
//int ledPin = 13;                // choose the pin for the LED
int inputPin = A0;               // choose the input pin (for PIR sensor)
int pirState = LOW;             // we start, assuming no motion detected
int val = LOW;                    // variable for reading the pin status

Adafruit_NeoPixel strip = Adafruit_NeoPixel(N_LEDS, PIN, NEO_GRB + NEO_KHZ800);

void setup() {
  strip.begin();
  pinMode(inputPin, INPUT);     // declare sensor as input
  Serial.begin(9600);
}

void loop() {

  val = digitalRead(inputPin);  // read input value
  if (val == HIGH) {            // check if the input is HIGH
    chase(strip.Color(0, 0, 255)); // Blue
    // digitalWrite(ledPin, HIGH);  // turn LED ON
    //if (pirState == LOW) {
      // we have just turned on
      Serial.println(“Motion detected!”);
      // We only want to print on the output change, not state
    //  pirState = HIGH;
  //  }
  } else {
    // digitalWrite(ledPin, LOW); // turn LED OFF
   // if (pirState == HIGH) {
      // we have just turned of
      Serial.println(“Motion ended!”);
      // We only want to print on the output change, not state
    //  pirState = LOW;
  //  }
  }
  //chase(strip.Color(255, 0, 0)); // Red
  //chase(strip.Color(0, 255, 0)); // Green
 // chase(strip.Color(0, 0, 255)); // Blue
}

static void chase(uint32_t c) {
  for (uint16_t i = 0; i < strip.numPixels() + 4; i++) {
    strip.setPixelColor(i  , c); // Draw new pixel
    strip.setPixelColor(i – 4, 0); // Erase pixel a few steps back
    strip.show();
    delay(200);
  }
}