#include <Adafruit_NeoPixel.h>
int dout = 9;
int a0 = A0;
int n = 16;
int intensity = 0;
Adafruit_NeoPixel ring = Adafruit_NeoPixel(n, dout);
void setup() {
  // put your setup code here, to run once:
  ring.begin();
  Serial.begin(9600);
}
int color (uint32_t col){
  for(int i = 0; i<n; i++){
    ring.setPixelColor(i, col);
    ring.show();
    delay(500);
  }
}
void loop() {
  // put your main code here, to run repeatedly:
  intensity = analogRead(a0);
  Serial.println(intensity);
  if(intensity>1000){
    Serial.println("red");
    color(ring.Color(255,0,0));
  }
  else if(intensity>500){
    Serial.println("yellow");
    color(ring.Color(255,255,0));
  }
  else{
    Serial.println("green");
    color(ring.Color(0,255,0));
  }
}