SMI_LAB6_EX1

#include <util/delay.h>
#include <LiquidCrystal.h>
LiquidCrystal lcd(12, NULL, 11, 9, 8, 7, 6);
volatile int nr_secunde = 50;
volatile int minutes = 59;
volatile int hours = 0;

void setup() {
  TIMSK1 = (1 << TOIE1);  // activare timer overflow
  TCCR1A = 0;
  TCCR1B = 0;  // timer stop
  //activare INT0, INT1, PCINT20
  EIMSK = (1 << INT0);
  EIMSK |= (1 << INT1);
  //activare PCI2 (buton 3 - PCINT20 - PCI2)
  PCICR |= (1 << PCIE2);
  PCMSK2 |= (1 << PCINT20);
  //configurare LCD
  lcd.begin(16, 2);
  lcd.noCursor();
}

void loop() {
  lcd.setCursor(0, 1);

  if (hours < 10) lcd.print("0");
  lcd.print(hours);
  lcd.print("h");

  if (minutes < 10) lcd.print("0");
  lcd.print(minutes);
  lcd.print("m");

  if (nr_secunde < 10) lcd.print("0");
  lcd.print(nr_secunde);
  lcd.print("s");
}

ISR(TIMER1_OVF_vect) {
  TCNT1 = 0x0BDC;
  nr_secunde++;
  if (nr_secunde == 60) {
    nr_secunde = 0;
    minutes++;
  }

  if (minutes == 60) {
    minutes = 0;
    hours++;
  }
}

ISR(INT0_vect) {
  TCNT1 = 0x0BDC;
  TCCR1A = 0;
  TCCR1B = (1 << CS12);  // timer start
  _delay_ms(400);
}
ISR(INT1_vect) {
  TCCR1A = 0;
  TCCR1B = 0;  // timer stop
  _delay_ms(400);
}

ISR(PCINT2_vect) {
  nr_secunde = 0;  //reset cronometru
  minutes = 0;
  hours = 0;
  _delay_ms(400);
}