#define led_pin 6
#define low_brightness 64
#define normal_brightness 128
#define high_brightness 255
#define no_brightness 0
const int duration=1000;

void setup() {
  // put your setup code here, to run once:
  pinMode(led_pin,OUTPUT);
  Serial.begin(9600);
  }

void loop() {
  // put your main code here, to run repeatedly:
  analogWrite(led_pin,no_brightness);
  Serial.println(no_brightness);
  delay(duration);
  analogWrite(led_pin,low_brightness);
  Serial.println(low_brightness);
  delay(duration);
  analogWrite(led_pin,normal_brightness);
  Serial.println(normal_brightness);
  delay(duration);
  analogWrite(led_pin,high_brightness);
  Serial.println(high_brightness);
  delay(duration);
  }