Detecting Obstacles and Warn using Arduino-Ultrasonic

1int ledPIN = 7;
2int speakerPIN = 9;
3int trigPIN = 13;
4int echoPIN
5  = 11;
6boolean buttonOn = false;
7void setup() {
8  // put your setup code
9  here, to run once:
10  pinMode(ledPIN, OUTPUT);
11  pinMode(echoPIN, INPUT);
12
13  pinMode(trigPIN, OUTPUT);
14  Serial.begin(9600);
15}
16
17void loop() {
18
19
20  long duration, distance;
21  digitalWrite(trigPIN,HIGH);
22  delayMicroseconds(1000);
23
24  digitalWrite(trigPIN,LOW);
25  duration = pulseIn(echoPIN,HIGH);
26  distance
27  = (duration/2)/29.1;
28  Serial.print(distance);
29  Serial.println("CM");
30
31  delay(10);
32 
33  if (distance < 10) {
34    digitalWrite(ledPIN, HIGH);
35
36    tone(speakerPIN,1000);
37  }
38  else {
39    digitalWrite(ledPIN, LOW);
40
41    noTone(speakerPIN);
42  }
43}

1int ledPIN = 7;
2int speakerPIN = 9;
3int trigPIN = 13;
4int echoPIN  = 11;
5boolean buttonOn = false;
6void setup() {
7  // put your setup code  here, to run once:
8  pinMode(ledPIN, OUTPUT);
9  pinMode(echoPIN, INPUT);
10  pinMode(trigPIN, OUTPUT);
11  Serial.begin(9600);
12}
13
14void loop() {
15
16  long duration, distance;
17  digitalWrite(trigPIN,HIGH);
18  delayMicroseconds(1000);
19  digitalWrite(trigPIN,LOW);
20  duration = pulseIn(echoPIN,HIGH);
21  distance  = (duration/2)/29.1;
22  Serial.print(distance);
23  Serial.println("CM");
24  delay(10);
25 
26  if (distance < 10) {
27    digitalWrite(ledPIN, HIGH);
28    tone(speakerPIN,1000);
29  }
30  else {
31    digitalWrite(ledPIN, LOW);
32    noTone(speakerPIN);
33  }
34}