const int Infraredpin=2;
const int LED=13;
void setup()
{ 
pinMode(LED,OUTPUT);
pinMode(Infraredpin, INPUT);
Serial.begin(9600);
}
void loop()
{
if(digitalRead(Infraredpin)==HIGH)
{ digitalWrite(LED,HIGH);
Serial.println("anything move in!");
}
else{ digitalWrite(LED,LOW);
Serial.println("this is nothing!");
}
delay(1000);
}