// LDR Sensor with nano
#define ldr 2;
#define led 11;
void setup() {
pinMode(2,INPUT);
pinMode(11,OUTPUT);
}

void loop() {
  int val = digitalRead(2);
  
  if (val == 0) {
    digitalWrite(11,HIGH);
  }
  else {
    digitalWrite(11,LOW);
  }

}