#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Keypad.h>
LiquidCrystal_I2C lcd(0x27,16,2);
const int echoPin=3;
const int triggerPin=2;
long duration;
int distence=0;
const byte ROWS = 4;
const byte COLS = 4;
char keys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};
byte rowPins[ROWS] = {11, 10, 9, 8};
byte colPins[COLS] = {7, 6, 5, 4};
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

// variables to store the two numbers
int R = 0;
int H  = 0;
float S=0;
float U=0;
float Q=0;
float volume=0;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(triggerPin,OUTPUT);
  pinMode(echoPin, INPUT);
  lcd.begin(16,2);
  lcd.setCursor(0,0);
  lcd.print("welcom  ");
  lcd.setCursor(0,1);
  lcd.print("TO MY PROJECT ");
  delay(2000);
  lcd.clear();
   lcd.clear();
  lcd.print("enter radius:");
  
  // get the first number from the keypad
  lcd.setCursor(0,1);
  char key = keypad.waitForKey();
  while (key != '#') {
    if (key >= '0' && key <= '9') {
      R = R * 10 + (key - '0');
      
      lcd.print(key);
    }
    key = keypad.waitForKey();
  }
  
  // clear the LCD and display message for the second number
  lcd.clear();
  lcd.print("enter Height:");
  
  // get the second number from the keypad
  lcd.setCursor(0,1);
  key = keypad.waitForKey();
  while (key != '#') {
    if (key >= '0' && key <= '9') {
      H = H * 10 + (key - '0');
     
      lcd.print(key);
    }
    key = keypad.waitForKey();
  }
  

}

void loop() {
  // put your main code here, to run repeatedly:lcd.clear();
 
  
  // clear the LCD and display the two numbers
  lcd.clear();

  delay(300);
  digitalWrite(triggerPin, LOW);
  delayMicroseconds(2);
  digitalWrite(triggerPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(triggerPin, LOW);
  duration=pulseIn(echoPin,HIGH);
  distence=duration*0.034/2;
  S=R*R*3.14;
  U=distence*S;
  Q=S*H;
  volume =(Q-U)/1000;
  lcd.setCursor(0,0);
  lcd.print("volume (l); ");
  lcd.setCursor(0,1);
  lcd.print(volume);
  lcd.setCursor(11,1);
  lcd.print("litre");
  delay(3000);
 


}