int six = 6;

void setup() {
pinMode(6, OUTPUT);
Serial.begin(9600);
}

void loop() {
analogWrite(six, 5);
int s1 = analogRead(six);
Serial.println(s1);
delay(2000);

analogWrite(six, 20);
int s2 = analogRead(six);
Serial.println(s2);
delay(2000);

analogWrite(six, 40);
int s3 = analogRead(six);
Serial.println(s3);
delay(2000);
}