#include <LiquidCrystal_I2C.h>      // liquidcrystal i2c
LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C address 0x27, 16 column and 2 rows
#include <math.h>

int distance[6];
float Volume = 0.0;

void setup() {
   Serial.begin(115200);

  lcd.init();                   // initialize the lcd
  lcd.backlight();              // Turn LCD light ON
  lcd.clear();                  // clear display
  lcd.setCursor(0, 1);          // move cursor to   (0, 0)
  if(Volume == 0.0){
      lcd.print("Calculating ... ");// print message at (0, 0)
  }
  else{
  lcd.print("Volume=");// print message at (0, 0)
  }
  for (int i=15; i<=17; i++) {
    pinMode(i, INPUT);        // Set Pin2 as Input Pin  (connected to ECHO Pin)
  }
  pinMode(A0, OUTPUT);        // Set Pin3 as Output Pin (connected to TRIG Pin)
}

void loop() {
  if(Volume != 0.0){
    lcd.setCursor(0, 1);          // move cursor to   (0, 0)
    lcd.print("Volume=");// print message at (0, 0)
    lcd.print(Volume);// print message at (0, 0)
    lcd.print(" m^3");// print message at (0, 0)
  }
  int j = 2;
    // Start a new measurement:

  for (int i=15; i<=17; i++) {
    digitalWrite(A0, HIGH);          // Start sending the UltraSound Sound
    delayMicroseconds(10);          // Sending Duration 10uSec.
    digitalWrite(A0, LOW);           // End sending the UltraSound Sound

    // Read the result:
    distance[i] = pulseIn(i, HIGH) / 58; 
    lcd.setCursor(0, 0);          // move cursor to      (2, 1)
    if(i == 15) {
      lcd.print("LENGTH= ");    // Clear The Screen at (2, 1)
    }

    else if(i == 16) {
      lcd.print("HEIGHT= ");    // Clear The Screen at (2, 1)
    }

    else if(i == 17) {
      lcd.print("WIDTH = ");    // Clear The Screen at (2, 1)
    }

    lcd.print(distance[i] / 100.0);          // print message at    (2, 1)
    lcd.print(" m");          // print message at    (2, 1)

    delay(2000); 
  }
    Volume = (distance[15] / 100.0) * (distance[16] / 100.0) * (distance[17] / 100.0);

    delay(500);      
}