Limit the crowd to prevent the spread of COVID-19

1// LIMIT THE CROWD TO PREVENT THE SPREAD OF COVID-19
2// ARDUINO PROJECTS  BY R
3// AUTHOR: RUCKSIKAA RAAJKUMAR
4#include <LiquidCrystal_I2C.h>
5#include  <Wire.h>
6#include <Servo.h>
7#define trig 4
8#define echo 3
9const int  out_sensor=5;
10int out_state;
11Servo servo;
12LiquidCrystal_I2C lcd(0x27,16,2);
13int  count; // Variable to store the number of people inside
14int limit = 15; // The  maximum occupancy 
15long duration;
16int distance;
17void setup() { // put your  setup code here, to run once:
18  pinMode(out_sensor, INPUT); // Configure the  pin of the IR tracking sensor as INPUT
19  pinMode(trig, OUTPUT); // Configure  the trig pin of the Ultrasonic sensor module as OUTPUT as it emits ultrasonic waves  (pulse)
20  pinMode(echo, INPUT); // Configure the echo pin of the echo pin as  INPUT
21  Serial.begin(9600);
22  servo.attach(9); // Servo motor is connected  to D9
23  servo.write(0); // Set the initial position of servo motor as 0 degrees.
24  lcd.begin();
25}
26void loop() { // put your main code here, to run repeatedly:
27  if(count==limit){ // If maximum occupancy is reached
28    lcd.clear();
29    lcd.setCursor(1,0);
30    lcd.print("Max. occupancy");
31    lcd.setCursor(5,1);
32    lcd.print("reached");
33  }else{ // If maximum occupancy is not reached
34    lcd.clear();
35    lcd.print("No.  of people=");
36    lcd.print(count);
37  }
38  digitalWrite(trig, LOW);
39  delayMicroseconds(5);
40  digitalWrite(trig, HIGH);
41  delayMicroseconds(10);
42  digitalWrite(trig, LOW);
43  duration = pulseIn(echo, HIGH); // Calculate time  taken (in microseconds) for the pulse emitted by the trigger pin to reach the echo  pin.
44  distance = (duration/2) * (331.3/10000); // Calculate the distance from  the sensor to the obstacle in cm, using the speed of sound in air(m/s) and the time  taken (stored in duration variable)
45  Serial.println(distance);
46  out_state=digitalRead(out_sensor);  
47  Serial.println(count);
48  if(out_state==LOW){ // If anyone hovers over the  IR sensor
49    count--; // Value stored in count variable will be decreased by  one as the person is exiting the building or vehicle
50    servo.write(90); 
51    delay(5000); // Door will remain open for 5 seconds
52    servo.write(0);
53    if(count<0){
54      count=0;
55    }
56  }
57  if(distance<5){
58    if(count>limit){  // If value stored in count variable is greater than maximum occupancy
59      lcd.clear();
60      lcd.print("You can't enter");
61      lcd.setCursor(6,1);
62      lcd.print("now");
63      delay(2000);
64    }else{
65      count++; // Count will increase by one  as a person is entering
66      servo.write(90);
67      delay(5000);
68      servo.write(0);
69    }
70  } 
71}

1// LIMIT THE CROWD TO PREVENT THE SPREAD OF COVID-19
2// ARDUINO PROJECTS
3  BY R
4// AUTHOR: RUCKSIKAA RAAJKUMAR
5#include <LiquidCrystal_I2C.h>
6#include
7  <Wire.h>
8#include <Servo.h>
9#define trig 4
10#define echo 3
11const int
12  out_sensor=5;
13int out_state;
14Servo servo;
15LiquidCrystal_I2C lcd(0x27,16,2);
16int
17  count; // Variable to store the number of people inside
18int limit = 15; // The
19  maximum occupancy 
20long duration;
21int distance;
22void setup() { // put your
23  setup code here, to run once:
24  pinMode(out_sensor, INPUT); // Configure the
25  pin of the IR tracking sensor as INPUT
26  pinMode(trig, OUTPUT); // Configure
27  the trig pin of the Ultrasonic sensor module as OUTPUT as it emits ultrasonic waves
28  (pulse)
29  pinMode(echo, INPUT); // Configure the echo pin of the echo pin as
30  INPUT
31  Serial.begin(9600);
32  servo.attach(9); // Servo motor is connected
33  to D9
34  servo.write(0); // Set the initial position of servo motor as 0 degrees.
35
36  lcd.begin();
37}
38void loop() { // put your main code here, to run repeatedly:
39
40  if(count==limit){ // If maximum occupancy is reached
41    lcd.clear();
42    lcd.setCursor(1,0);
43
44    lcd.print("Max. occupancy");
45    lcd.setCursor(5,1);
46    lcd.print("reached");
47
48  }else{ // If maximum occupancy is not reached
49    lcd.clear();
50    lcd.print("No.
51  of people=");
52    lcd.print(count);
53  }
54  digitalWrite(trig, LOW);
55
56  delayMicroseconds(5);
57  digitalWrite(trig, HIGH);
58  delayMicroseconds(10);
59
60  digitalWrite(trig, LOW);
61  duration = pulseIn(echo, HIGH); // Calculate time
62  taken (in microseconds) for the pulse emitted by the trigger pin to reach the echo
63  pin.
64  distance = (duration/2) * (331.3/10000); // Calculate the distance from
65  the sensor to the obstacle in cm, using the speed of sound in air(m/s) and the time
66  taken (stored in duration variable)
67  Serial.println(distance);
68  out_state=digitalRead(out_sensor);
69  
70  Serial.println(count);
71  if(out_state==LOW){ // If anyone hovers over the
72  IR sensor
73    count--; // Value stored in count variable will be decreased by
74  one as the person is exiting the building or vehicle
75    servo.write(90); 
76
77    delay(5000); // Door will remain open for 5 seconds
78    servo.write(0);
79
80    if(count<0){
81      count=0;
82    }
83  }
84  if(distance<5){
85    if(count>limit){
86  // If value stored in count variable is greater than maximum occupancy
87      lcd.clear();
88
89      lcd.print("You can't enter");
90      lcd.setCursor(6,1);
91      lcd.print("now");
92
93      delay(2000);
94    }else{
95      count++; // Count will increase by one
96  as a person is entering
97      servo.write(90);
98      delay(5000);
99      servo.write(0);
100
101    }
102  } 
103}