int ds_pin = 4;
int stc_pin = 5;
int shc_pin = 2;

String data;
String a_1;
String a_2;
String a_3;
String a_4;

int a;
int b;
int c;
int d;

int i = 10;

int dec_digits[10] = {1,79,18,6,76,36,32,15,0,4};

void setup() {
  Serial.begin(115200);
  pinMode(ds_pin, OUTPUT);
  pinMode(stc_pin, OUTPUT);
  pinMode(shc_pin, OUTPUT);
}

void loop() {
  if(Serial.available()){
    data = Serial.readString();

    a_1 = data[0];
    a_2 = data[1];
    a_3 = data[2];
    a_4 = data[3];

    a = a_1.toInt();
    b = a_2.toInt();
    c = a_3.toInt();
    d = a_4.toInt();


    digitalWrite(stc_pin,LOW);
    shiftOut(ds_pin, shc_pin, LSBFIRST,dec_digits[d]);
    shiftOut(ds_pin, shc_pin, LSBFIRST,dec_digits[c]);
    shiftOut(ds_pin, shc_pin, LSBFIRST,dec_digits[b]);
    shiftOut(ds_pin, shc_pin, LSBFIRST,dec_digits[a]);
    digitalWrite(stc_pin,HIGH);
     
    // if(a == 1){
    //   digitalWrite(stc_pin,LOW);
    //   shiftOut(ds_pin, shc_pin, LSBFIRST,dec_digits[1]);
    //   digitalWrite(stc_pin,HIGH);
    //   Serial.println("blblbbl");
    // }

    
  }
   
}