#include <Servo.h>

int echoPin = 2;
int initPin = 3;
unsigned long pulseTime = 0;
unsigned long distance = 0;

Servo myServo;
int servoPin = 9;
int pos = 0;

void setup() {
  // put your setup code here, to run once:
  myServo.attach(servoPin);
  pinMode(initPin,OUTPUT);
  pinMode(echoPin,INPUT);
  Serial.begin(9600);
}

void cal(){
    digitalWrite(initPin,LOW);
    delayMicroseconds(50);
    digitalWrite(initPin,HIGH);
    delayMicroseconds(50);
    digitalWrite(initPin,LOW);

    pulseTime = pulseIn(echoPin,HIGH);
    distance = pulseTime/58;
    Serial.print(distance);
    Serial.println();
}

int cnt = 0;

void loop() {
  // put your main code here, to run repeatedly:
    cnt += 1;

    Serial.println("one");

    for ( pos = 0 ; pos < 180 ; pos += 1 ){

      myServo.write(pos);
      cal();
      delay(15);
    }

    Serial.println("two");

    for ( pos = 180 ; pos > 0 ; pos -= 1 ){
      myServo.write(pos);
      cal();
      delay(15);
    }

  delay(100);
  if (cnt == 2) return;
}