int pin = 9;
int data = 0;
int count = 0;

void setup() {
  Serial.begin(9600);     // opens serial port, sets data rate to 9600 bps
}

void loop() {
  count ++;
  if (count < 30){
    data = analogRead(pin);
    Serial.println(data);
  }else{

    Serial.println("End");
    Serial.end();
  }

}