int ldr = A0;

void setup() {
  Serial.begin(9600);
  pinMode(3, OUTPUT);

}

void loop() {
int ldrnilai = analogRead(ldr);
Serial.print("Nilai cahaya: ");
if (ldrnilai <= 500){
  Serial.println("terang");
  digitalWrite(3, LOW);
delay(600);
}
else{
  Serial.println("gelap");
  digitalWrite(3, HIGH);
delay(600);
}

}