Ultrasonic security system

1//Security Alarm with Ultrasonic Sensor//
2
3#define trigPin 6  
4#define  echoPin 5
5#define buzzer 2
6float new_delay; 
7
8
9void setup() 
10{
11  Serial.begin (9600); 
12  pinMode(trigPin, OUTPUT); 
13  pinMode(echoPin, INPUT);
14  pinMode(buzzer,OUTPUT);
15  
16}
17
18
19void loop() 
20{
21  long duration,  distance;
22  digitalWrite(trigPin, LOW);        
23  delayMicroseconds(2);              
24  digitalWrite(trigPin, HIGH);
25  delayMicroseconds(10);           
26  digitalWrite(trigPin,  LOW);
27  duration = pulseIn(echoPin, HIGH);
28  distance = (duration/2) / 29.1;
29  new_delay= (distance *3) +30;
30  Serial.print(distance);
31  Serial.println("  cm");
32  if (distance < 50)
33  {
34   digitalWrite(buzzer,HIGH);
35   delay(new_delay);
36   digitalWrite(buzzer,LOW);
37 
38  }
39  else
40  {
41    digitalWrite(buzzer,LOW);
42
43  }
44  
45 delay(200);
46}
47

1//Security Alarm with Ultrasonic Sensor//
2
3#define trigPin 6  
4#define
5  echoPin 5
6#define buzzer 2
7float new_delay; 
8
9
10void setup() 
11{
12
13  Serial.begin (9600); 
14  pinMode(trigPin, OUTPUT); 
15  pinMode(echoPin, INPUT);
16
17  pinMode(buzzer,OUTPUT);
18  
19}
20
21
22void loop() 
23{
24  long duration,
25  distance;
26  digitalWrite(trigPin, LOW);        
27  delayMicroseconds(2);              
28
29  digitalWrite(trigPin, HIGH);
30  delayMicroseconds(10);           
31  digitalWrite(trigPin,
32  LOW);
33  duration = pulseIn(echoPin, HIGH);
34  distance = (duration/2) / 29.1;
35
36  new_delay= (distance *3) +30;
37  Serial.print(distance);
38  Serial.println("
39  cm");
40  if (distance < 50)
41  {
42   digitalWrite(buzzer,HIGH);
43   delay(new_delay);
44
45   digitalWrite(buzzer,LOW);
46 
47  }
48  else
49  {
50    digitalWrite(buzzer,LOW);
51
52
53  }
54  
55 delay(200);
56}
57