int led_pin = 4;
int pir_pin = 3;
int ldr_pin = A0;

int pir_value, ldr_value;

void setup() {
 pinMode(led_pin, OUTPUT);
 pinMode(pir_pin, INPUT);

 Serial.begin(9600);

}

void loop() {
  ldr_value = analogRead(ldr_pin);
  pir_value = digitalRead(pir_pin);

  Serial.print(ldr_value);
  Serial.print(" - ");
  Serial.println(pir_value);

  if(ldr_value > 500) {
    if (pir_value == 1) {
      digitalWrite(led_pin, HIGH);
    }
    else {
      digitalWrite(led_pin, LOW);
    }
  }


}