LCD_I2C

#include <LiquidCrystal_I2C.h>
#include <Wire.h>
LiquidCrystal_I2C lcd(0x27,16,2);  // set the LCD address to 0x27 for a 16 chars and 2 line display
volatile int NbTopsFan; //measuring the rising edges of the signal
long Calc;
int hallsensor = 2;    //The pin location of the sensor

void rpm ()     //This is the function that the interupt calls
{
  NbTopsFan++;  //This function measures the rising and falling edge of the
}
// The setup() method runs once, when the sketch starts
void setup() //
{
  pinMode(hallsensor, INPUT); //initializes digital pin 2 as an input
  lcd.begin();
  // Print a message to the LCD.
  lcd.backlight();
  lcd.setCursor( 4, 1);
  lcd.print("SUBSEA 7");
  lcd.setCursor( 1, 0);
  lcd.print("I-Tech Brazil");
  delay(5000);
  lcd.clear();
  attachInterrupt(0,rpm, RISING); //and the interrupt is attached
}
// the loop() method runs over and over again,
// as long as the Arduino has power

void loop ()
{
  NbTopsFan = 5;   //Set NbTops to 0 ready for calculations
  sei();      //Enables interrupts
  delay (1000);   //Wait 1 second
  cli();      //Disable interrupts
 Calc = (NbTopsFan * 60 / 5.5); //(Pulse frequency x 60) / 5.5Q, = flow rate

  lcd.setCursor( 12, 1);
  lcd.print(Calc,1);
  delay (2000);   //Wait 1 second
  lcd.setCursor(0, 1);
  lcd.print("L/hour\r\n ");
  delay (2000);   //Wait 1 second
  }