Smart Car Parkcing system | Created NJ

#include <SoftwareSerial.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);


#define trig 3
#define echo 5

#define trig1 2
#define echo1 4

#define tri 9
#define ech 8

int timer = 0;
int timer2 = 0;
int timer3 = 0;

SoftwareSerial BT(10, 11);  //tx ,rx
void setup() {

  lcd.init();
  BT.begin(9600);
  pinMode(2, OUTPUT);  //1red
  pinMode(12, OUTPUT);  //1gre
  pinMode(16, OUTPUT);  //2gre
  pinMode(7, OUTPUT);   //2red
  pinMode(18, OUTPUT);  //3gre
  pinMode(19, OUTPUT);  //3red
  pinMode(trig,OUTPUT);
  pinMode(echo,INPUT);
  pinMode(trig1, OUTPUT);
  pinMode(echo1, INPUT);
  pinMode(tri, OUTPUT);
  pinMode(ech, INPUT);
  Serial.begin(9600);
}

void loop() {
  
  digitalWrite(trig, LOW);
  delayMicroseconds(2);
  digitalWrite(trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig, LOW);

  long z = pulseIn(echo, HIGH);

  long inches = z / 74 / 2;
  long cm = z / 29 / 2;

  Serial.print(inches);  //6 in    15cm
  Serial.print("in \z ");
  Serial.print(cm);
  Serial.println("cm");
  delay(100);

  lcd.begin(16, 2);
  lcd.setCursor(1, 0);
  lcd.print("All part is free");
  lcd.backlight();

  digitalWrite(2, HIGH);

  if (cm < 10 && timer==5) {
    
    digitalWrite(2, LOW);
    digitalWrite(12, HIGH);
    lcd.setCursor(1, 0);
    lcd.print("Part 1 is sold");
    BT.println("Part 1 is sold");
    timer = timer + 1;
    delay(1000);

    if (timer == 15) {
      BT.println("Part 1 car cost");
      BT.println("You charge is Rs 20.00");
      lcd.setCursor(1, 0);
      lcd.print("Part1 car cost");
      lcd.print("Your charge is Rs 20.20");
      lcd.clear();
    }
  timer=0;
  }


  else if (cm > 10){
    digitalWrite(2, HIGH);
    digitalWrite(12, LOW);
    lcd.print("Part 1 is empty");  // part 01
    BT.println("Part 1 is empty");

  }
  digitalWrite(trig1, LOW);
  delayMicroseconds(2);
  digitalWrite(trig1, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig1, LOW);

  long t = pulseIn(echo1, HIGH);

  long inche = t / 74 / 2;
  long cmm = t / 29 / 2;

  Serial.print(inche);  //6 in    15cm
  Serial.print("in1 \t ");
  Serial.print(cmm);
  Serial.println("cm1");
  delay(1000);

  digitalWrite(16, HIGH);

  if (cmm < 10) {
    
    digitalWrite(16, LOW);
    digitalWrite(7, HIGH);
    lcd.setCursor(1, 1);
    lcd.print("Part 2 is sold");
    BT.println("Part 2 is sold");
   
    timer2 = timer2 + 1;
    delay(1000);
    

       if (timer2 == 15) {
      lcd.setCursor(1,0);
      lcd.print("Part 2 car cost");
      lcd.setCursor(1,1);
      lcd.print("Part 2 cost is Rs 20.00");
      BT.print("Part 2 car cost");
      BT.print("Part 2 cost is Rs 20.00");
      lcd.clear();
      
    }
  timer2=0;
  }

  else if (cmm > 10) {
      digitalWrite(7, LOW);
      digitalWrite(16, HIGH);
      lcd.setCursor(1, 0);
      lcd.print("Part 2 is empty");  //part 02
      BT.println("Part 2 is empty");
      lcd.clear();
 
  }
  digitalWrite(tri, LOW);
  delayMicroseconds(2);
  digitalWrite(tri, HIGH);
  delayMicroseconds(10);
  digitalWrite(tri, LOW);

  long e = pulseIn(ech, HIGH);

  long inc = e / 74 / 2;
  long cmt = e / 29 / 2;

  Serial.print(inc);  //6 in    15cm
  Serial.print("in2 \e ");
  Serial.print(cmt);
  Serial.println("cm2");
  delay(100);

  digitalWrite(18, HIGH);

  if (cmt < 10) {
    
    digitalWrite(18, LOW);
    digitalWrite(19, HIGH);
    lcd.setCursor(1, 0);
    lcd.print("part 3 is full");
    BT.println("part 3 is full");
    timer3 = timer3 + 1;
    delay(1000);
    if (timer3 == 15) {
      lcd.setCursor(1, 0);
      lcd.print("Part 3 part cost");
      lcd.setCursor(1,1);
      lcd.print("part 3 cost is Rs 20.00");
    }
  timer3=0;
  }

  else if (cmt > 10) {
    digitalWrite(18, HIGH);
    digitalWrite(19, LOW);
    lcd.setCursor(1, 0);
    lcd.print("Part 3 is empty");  //part 03
    BT.println("Part 3 is empty");

  }
}