#define TRIG 4
#define MOTOR 6

boolean trigger = LOW;

void setup() {
  Serial.begin(9600);
  pinMode(TRIG, INPUT);
  pinMode(MOTOR, OUTPUT);
}

void loop() {
  
  trigger = digitalRead(TRIG);

  
  if(!trigger) {

    for(int i=0; i<25; i++) {
      analogWrite(MOTOR, i*10);
      delay(20);
    }
    delay(1000);
    for(int i=25; i>=0; i--) {
      analogWrite(MOTOR, i*10);
      delay(200);
    }

    delay(1000);
      
  } else {
    digitalWrite(MOTOR, LOW);
  }
}