#include <Servo.h>

const int trigPin =  6;
const int echoPin =  5;
const int servPin = 12;

long duration;
int distance;
Servo myServo;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  myServo.attach(servPin);
}

void loop() {
  ping();
  myServo.write (map(distance, 2, 397, 0, 179));
  delay(15); // allow servo to catch up to code
}

void ping() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  distance = 0.017 * pulseIn(echoPin, HIGH); // (speed of sound) / 2
}