11.18.ino

#include <Adafruit_NeoPixel.h>

#define PIN            13
#define NUMPIXELS      8
Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);
int sensorValue;

void setup() {
  // put your setup code here, to run once:
  pinMode(11, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(13, OUTPUT);
  pinMode(A0, INPUT);
  
  digitalWrite(11, LOW);
  digitalWrite(12, HIGH);
  digitalWrite(13, HIGH);

  Serial.begin(9600);
  
  pixels.begin();
  pixels.setBrightness(30);
}

void loop() {
  // For a set of NeoPixels the first NeoPixel is 0, second is 1, all the way up to the count of pixels minus one.
  
  sensorValue = analogRead(A0);

  Serial.println(sensorValue);
  if (sensorValue > 600) {
    for(int i=0;i<NUMPIXELS;i++){
      // pixels.Color takes RGB values, from 0,0,0 up to 255,255,255
      pixels.setPixelColor(i, pixels.Color(0,150,0)); // Moderately bright green color.
    }
    pixels.show(); // This sends the updated pixel color to the hardware.
    delay(500); // Delay for a period of time (in milliseconds).
  } else {
    for(int i=0;i<NUMPIXELS;i++){
      // pixels.Color takes RGB values, from 0,0,0 up to 255,255,255
      pixels.setPixelColor(i, pixels.Color(0,0,0)); // Moderately bright green color.
    }
    pixels.show(); // This sends the updated pixel color to the hardware.
    delay(500); // Delay for a period of time (in milliseconds).
  }
}