int led = 10;
int sensor = 3;
int state = LOW;
int val = 0;
int relayPin = 10;


void setup() {
  pinMode(led, OUTPUT);
  pinMode(sensor, INPUT);

  Serial.begin(9600);
  Serial.println("Setup-Start");
  pinMode(relayPin, OUTPUT);
}

void loop() {
  val = digitalRead(sensor);

  if (val == HIGH) {
    //Serial.println("val == HIGH");
    delay(100);

    if (state == LOW) {
      Serial.println("Motion detected!");
      state = HIGH;
      digitalWrite(relayPin, HIGH);

      Serial.println("start delay(1000)");
      delay(1000);
      Serial.println("delay(1000) finished");
    }
  }
  else {
    digitalWrite(led, LOW);
    delay(500);//500

    if (state == HIGH) {
      Serial.println("Motion stopped!");
      state = LOW;
      digitalWrite(relayPin, LOW);
      Serial.println("start delay(500)");
      delay(500);
      Serial.println("delay(500) finished");
    }
  }
}