#include <LiquidCrystal.h>

LiquidCrystal lcd(7, 6, 5, 4, 3, 2);

volatile int buttonVariable;

void setup() {
  buttonVariable = 0;
  lcd.begin(16, 2);
  lcd.print("A inceput");
  lcd.setCursor(0, 1);
  lcd.print("din nou");
  delay(1000);

  // The 2 interrupt pins 21 and 20 declared as inputs with
  // pull-up resistors activated
  pinMode(20 , INPUT);
  pinMode(21 , INPUT);
  digitalWrite(20, HIGH);
  digitalWrite(21, HIGH);

  // Attach ISRs to the interrupts corresponding to pins 21
  // and 20 (INT0 and INT1 respectively)
  attachInterrupt(digitalPinToInterrupt(20), functieUnu,
                  RISING);
  attachInterrupt(digitalPinToInterrupt(21), functieDoi,
                  CHANGE);
}

void loop() {
  // Insert here task for normal program flow ….
  lcd.print("Programul principal");
  delay(1000);
}

// First ISR function
void functieUnu() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Functia Unu");
}

// Second ISR function
void functieDoi() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Functia Doi");
}