#define LDR 5
#define LED 13
int ldr_val  = 0;
void setup()  
{
pinMode(LDR, INPUT);
pinMode(LED, OUTPUT);
Serial.begin(9600);
}
void loop () 
{
ldr_val = digitalRead(LDR);
Serial.println(ldr_val);
delay(2000);
if (ldr_val==1)
{
digitalWrite(LED, HIGH);
delay(5000);
}
else{
digitalWrite(LED, LOW);
delay(5000);
}
}