/*
 Controlling a servo position using a potentiometer (variable resistor)
 by Michal Rinott <http://people.interaction-ivrea.it/m.rinott>

 modified on 8 Nov 2013
 by Scott Fitzgerald
 http://www.arduino.cc/en/Tutorial/Knob
*/



//set names for connection of HC-SR04 -> Arduino pins
#define trigPin 10  //digital pin (read input + perform calc) 
#define echoPin 13  //normal pin

#include <Servo.h>
Servo myservo;  // create servo object to control a servo

int val;    // variable to read the value from the analog pin
float duration, distance;



void setup() {
  pinMode(trigPin, OUTPUT); //sending pulses out from trigPin
  pinMode(echoPin, INPUT);  //recieving rebound pulse as I/P, to calc dist

  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
  myservo.write(0);  //specifying initial speed and direction of servo
}

void loop() {
  //manually sending 10us pulse
  digitalWrite(trigPin, LOW); //starting LOW
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);  //sending high part of pulse
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW); //ending pulse

  duration = pulseIn(echoPin, HIGH);  //measures duration in which the Pulse stays high
  distance = (duration/2) * 0.0343;   //0.0343 cm/us is speed of sound

  //val = map(val, 0, 1023, 0, 180);     // scale it to use it with the servo (value between 0 and 180)
  if(distance <= 10) {
      myservo.write(180); //position of servo motor in degrees
      delay(550);  // waits for the servo to get there (1000us = 1s)
      myservo.write(0);
      delay(550);  // waits for the servo to get there
  }
                     
}