Proximity Alarm and distance monitor Using Ultrasonic Sensor

1// Code by theriveroars
2// On 25-8-2020
3
4
5#include <Servo.h>
6#include  <NewPing.h>
7
8Servo myservo;  // create servo object to control a servo
9
10
11const  int trigPin = 9;   // Trigger Pin of Ultrasonic Sensor
12const int echoPin = 10;  // Echo Pin of Ultrasonic Sensor
13const int red = 11;      // led to pin 11
14const  int buzz = 12;     // buzzer to pin 12
15const int serv0 = 8;     // servo to pin  8
16
17NewPing sonar (trigPin, echoPin, 300);      //300 is max distance
18
19int  pos = 0;    // variable to store the servo position
20
21void setup() {
22  myservo.attach(serv0);  // attaches the servo on pin 9 to the servo object
23  Serial.begin(9600); //  Starting Serial Terminal
24  pinMode(red, OUTPUT); // setting led pin as output
25  pinMode(buzz, OUTPUT); //setting buzzer pin as output
26}
27
28void loop()  {
29  long duration, inches, cm;
30  for (pos = pos; pos <= 180; pos += 5) { //  goes from 0 degrees to 180 degrees        // in steps of 5 degree
31    myservo.write(pos);              // tell servo to go to position in variable 'pos' //pos varies from  0 to 180 in steps of 5
32    delay(10);
33    int cm = sonar.ping_cm();   // gets  the distance in cm from the ultrasonic sensor
34    Serial.print(cm);
35    Serial.print("cm");     //prints the distance
36    Serial.println();
37
38    delay(15);
39
40    if (cm < 20)
41    {
42      analogWrite(red, 125);          // if distance  to object is less than 150 light up the red led to half its brightness
43      if  (cm < 10)     {            // if distance is less than 100
44        digitalWrite(red,  HIGH);    //light up red led to full brightness
45        digitalWrite(buzz, HIGH);     //switch on the buzzer
46      }
47      else digitalWrite(buzz, LOW);
48
49    }
50    else
51    { digitalWrite(buzz, LOW);     //otherwise switch of the  buzzer and led
52      digitalWrite(red, LOW);
53    }
54  }
55
56  for (pos  = 180; pos >= 0; pos -= 5) { // same thing is repeated for the turn from 180 to  0
57    myservo.write(pos);
58    delay(10);
59    int cm = sonar.ping_cm();
60
61    Serial.print(cm);
62    Serial.print("cm");
63    Serial.println();
64
65    delay(15 );  // waits 15ms for the servo to reach the position
66    if (cm  < 20)
67    {
68      analogWrite(red, 125);
69      if (cm < 10)
70      {
71
72        digitalWrite(red, HIGH);
73        digitalWrite(buzz, HIGH);
74      }
75      else digitalWrite(buzz, LOW);
76
77    }
78    else
79    { digitalWrite(buzz,  LOW);
80      digitalWrite(red, LOW);
81    }
82  }
83
84
85  delay(100);
86}
87