Ultrasonic sweep for objects with serial communication

1#include <Servo.h>
2
3Servo scanner;
4
5const int out = 12;
6const  int in = 13;
7int pos = 0;
8long dur;
9long dis;
10long tocm;
11bool returningToZero;
12
13void  setup() {
14  Serial.begin(9600);
15  pinMode(in, INPUT);
16  pinMode(out, OUTPUT);
17  scanner.attach(9);
18  scanner.write(0);
19}
20
21bool objectDetected(long  tocm)
22{
23  if (tocm < 20)
24  {
25    return true;
26  } else {
27    return  false;
28  }
29}
30
31void loop()
32{
33  digitalWrite(out, LOW);
34  delayMicroseconds(2);
35  digitalWrite(out, HIGH);
36  delayMicroseconds(10);
37  digitalWrite(out, LOW);
38  dur = pulseIn(in, HIGH);
39  tocm = microsecondsToCentimeters(dur);
40  if (objectDetected(tocm))
41  {
42    Serial.print("Object detected. Object's distance: ");
43    Serial.print(tocm);
44    Serial.print(". Servo's angle: ");
45    Serial.println(pos);
46  } else  {
47    if (pos < 180 && returningToZero == false)
48    {
49      scanner.write(pos);
50      pos += 10;
51      Serial.print("Searching for object. Servo's angle: ");
52      Serial.println(pos);
53      if (pos == 180)
54        returningToZero =  true;
55    } else if (returningToZero == true) {
56      pos -= 10;
57      Serial.print("Searching  for object. Servo's angle: ");
58      Serial.println(pos);
59      scanner.write(pos);
60      if (pos == 0)
61        returningToZero = false;
62    }
63  }
64  delay(200);
65}
66
67long  microsecondsToCentimeters(long microseconds)
68{
69  return microseconds / 29.155  / 2;
70}