void setup()
{
pinMode(4, INPUT);
pinMode(16, OUTPUT);
Serial.begin(9600);
}
void loop()
{
  int motion=0;
  motion=digitalRead(4);
  if (motion==HIGH)
  {
    digitalWrite(16, HIGH);
    Serial.println(motion);
    Serial.println("motion detected");
  }
  else
  {
  digitalWrite(16, LOW);
  Serial.println(motion );
  Serial.println("motion not detected");
}
delay(1000);
}