void setup() {
  Serial.begin(115200);
  pinMode(12, OUTPUT);
  pinMode(11, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(8, OUTPUT);
}

void loop() {
  int sensor = analogRead(A0);
  Serial.println(sensor);
  delay(1000);
  if (sensor < 200) {
    digitalWrite(12, HIGH);
    digitalWrite(11, LOW);
    digitalWrite(10, LOW);
    digitalWrite(9, LOW);
    digitalWrite(8, LOW);
  }
  else if (sensor >= 200 && sensor < 400) {
    digitalWrite(12, LOW);
    digitalWrite(11, HIGH);
    digitalWrite(10, LOW);
    digitalWrite(9, LOW);
    digitalWrite(8, LOW);
  }
  else if (sensor >= 400 && sensor < 600) {
    digitalWrite(12, LOW);
    digitalWrite(11, LOW);
    digitalWrite(10, HIGH);
    digitalWrite(9, LOW);
    digitalWrite(8, LOW);
  }
  else if (sensor >= 600 && sensor < 800) {
    digitalWrite(12, LOW);
    digitalWrite(11, LOW);
    digitalWrite(10, LOW);
    digitalWrite(9, HIGH);
    digitalWrite(8, LOW);
  }
  else {
    digitalWrite(12, LOW);
    digitalWrite(11, LOW);
    digitalWrite(10, LOW);
    digitalWrite(9, LOW);
    digitalWrite(8, HIGH);
  }
}