int pot1 = A0;
int lamp = 8;

int value1 = 0;

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

void loop() {
  value1 = analogRead(pot1);
  if(value1 > 551) {
    digitalWrite(lamp, HIGH);
  } else if (value1 < 551) {
    digitalWrite(lamp, LOW);
  }
}