// PORTA = D29, D28 ... D22 (msb -> lsb)
//              G        A

volatile int i = 0;
byte cifra[10] = {0b11000000, 0b11111001, 0b10100100, 0b10110000,
0b10011001, 0b10010010, 0b10000010, 0b11111000, 0b10000000, 0b10010000};
byte multiplexare[4] = {0B00000001, 0B00000010, 0B00000100, 0B00001000};

char th1 = A0, th2 = A1;
int read1 = 0;
volatile bool thCitit = true;

const float BETA = 3950; // should match the Beta Coefficient of the thermistor


void setup(){
  DDRA = 0B11111111;
  DDRD = 0B11111111;
  cli(); 
  TCCR1A = 0; 
  TCCR1B = 0;
  OCR1A = 2550;
  TCCR1B |= 0B00001101;
  TIMSK1 |= (1 << OCIE1A);

  TCCR2A = 0; 
  TCCR2B = 0;
  OCR2A = 255;
  TCCR2B |= 0B00000111;
  TCCR2A |= 0B10000010;
  TIMSK2 |= (1 << OCIE2A);

  sei(); 

  pinMode(th1, INPUT);
  pinMode(th2, INPUT);
}

void loop(){
  if(thCitit){
    read1 = getTemp(th2);
  }else{
    read1 = getTemp(th1);
  }
Serial.println(thCitit);
    afisare();
}

void afisare(){
    if(read1 < 0 || read1 > 100){
      PORTA = 0b10111111;
    }
    else{
      switch(i){
    case 0: PORTA = cifra[(read1 /1000) % 10];
    break;
    case 1: PORTA = cifra[(read1 /100) % 10];
    break;
    case 2: PORTA = cifra[(read1 /10) % 10];
    break;
    case 3: PORTA = cifra[read1 % 10];
  }
    }
  
  PORTD = multiplexare[i];
}

ISR(TIMER1_COMPA_vect){
  i = (i + 1) % 4;
}

int getTemp(int r){
  int analogValue = analogRead(r);
    float celsius = 1 / (log(1 / (1023. / analogValue - 1)) / BETA + 1.0 / 298.15) - 273.15;
    return round(celsius);
}

ISR(TIMER2_COMPA_vect){
  thCitit = !thCitit;
}