#define pinldr 36
#define pinled 21

int lightVal;
int lightInit;  

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("LDR readings..");
  pinMode(pinldr, INPUT);
  pinMode(pinled, OUTPUT);  
  lightInit = analogRead(pinldr);
}

void loop() {
  lightVal = analogRead(pinldr);
  if(lightVal - lightInit >  50)
  {
      digitalWrite (pinled, HIGH); // turn on light
      Serial.println("Keadaan gelap, lampu menyala");
  }
  else
  {
    digitalWrite (pinled, LOW); // turn off light
    Serial.println("Keadaan terang, lampu mati");
  }  
  Serial.println("Ligth Value :");
  Serial.println(lightVal);
  delay(500); // this speeds up the simulation
}