Up Down Counter Circuit

const int dispA = 2;
const int dispB = 3;
const int dispC = 4;
const int dispD = 5;
const int dispE = 6;
const int dispF = 7;
const int dispG = 8;

const int com1 = 9;
const int com10 = 10;
const int com100 = 11;

const int buzzer = 12;

const int btnUp = A0;
const int btnDown = A1;


void setup() {
  showNumber(0);

  pinMode(dispA, OUTPUT);
  pinMode(dispB, OUTPUT);
  pinMode(dispC, OUTPUT);
  pinMode(dispD, OUTPUT);
  pinMode(dispE, OUTPUT);
  pinMode(dispF, OUTPUT);
  pinMode(dispG, OUTPUT);

  pinMode(buzzer, OUTPUT);
  
  pinMode(com1, OUTPUT);
  pinMode(com10, OUTPUT);
  pinMode(com100, OUTPUT);

  pinMode(btnUp, INPUT_PULLUP);
  pinMode(btnDown, INPUT_PULLUP);
}

int numberValue = 0;
char statusBtnUp = '1';
char statusBtnDown = '1';

void loop() {

  if (statusBtnUp == '1' && digitalRead(btnUp) == LOW) { 
    statusBtnUp = '0';
    digitalWrite(buzzer, HIGH);
    delay(100);
    digitalWrite(buzzer, LOW);
    if (numberValue < 100) {
      numberValue++;
    }
  } else if (statusBtnUp == '0' && digitalRead(btnUp) == HIGH) { 
    statusBtnUp = '1';
  }

  if (statusBtnDown == '1' && digitalRead(btnDown) == LOW) { 
    statusBtnDown = '0';
    digitalWrite(buzzer, HIGH);
    delay(100);
    digitalWrite(buzzer, LOW);
    if (numberValue > 0)numberValue--;
  } else if (statusBtnDown == '0' && digitalRead(btnDown) == HIGH) { 
    statusBtnDown = '1';
  }
  showNumber(numberValue);
}

void showNumber(int number) {
  int ones = number % 10;
  selectDigit(1);
  showDigit(ones);
  delay(1);

  int tens = number / 10;
  selectDigit(10);
  showDigit(tens);
  delay(1);

  int hundreds = number / 100;
  selectDigit(100);
  showDigit(hundreds);
  delay(1);
}

 

void selectDigit(int selectedDigit) {
  showDigit(-1);
  delay(1);
  switch (selectedDigit) {
    case 1:
      digitalWrite(com1, HIGH);
      digitalWrite(com10, LOW);
      digitalWrite(com100, LOW);
      break;
    case 10:
      digitalWrite(com1, LOW);
      digitalWrite(com10, HIGH);
      digitalWrite(com100, LOW);
      break;
    case 100:
      digitalWrite(com1, LOW);
      digitalWrite(com10, LOW);
      digitalWrite(com100, HIGH);
      break;
    default:
      digitalWrite(com1, LOW);
      digitalWrite(com10, LOW);
      digitalWrite(com100, LOW);
  }
}

void showDigit(int digit) {
  switch (digit) {
    case 0:
      digitalWrite(dispA, HIGH);
      digitalWrite(dispB, HIGH);
      digitalWrite(dispC, HIGH);
      digitalWrite(dispD, HIGH);
      digitalWrite(dispE, HIGH);
      digitalWrite(dispF, HIGH);
      digitalWrite(dispG, LOW);
      break;
    case 1:
      digitalWrite(dispA, LOW);
      digitalWrite(dispB, HIGH);
      digitalWrite(dispC, HIGH);
      digitalWrite(dispD, LOW);
      digitalWrite(dispE, LOW);
      digitalWrite(dispF, LOW);
      digitalWrite(dispG, LOW);
      break;
    case 2:
      digitalWrite(dispA, HIGH);
      digitalWrite(dispB, HIGH);
      digitalWrite(dispC, LOW);
      digitalWrite(dispD, HIGH);
      digitalWrite(dispE, HIGH);
      digitalWrite(dispF, LOW);
      digitalWrite(dispG, HIGH);
      break;
    case 3:
      digitalWrite(dispA, HIGH);
      digitalWrite(dispB, HIGH);
      digitalWrite(dispC, HIGH);
      digitalWrite(dispD, HIGH);
      digitalWrite(dispE, LOW);
      digitalWrite(dispF, LOW);
      digitalWrite(dispG, HIGH);
      break;
    case 4:
      digitalWrite(dispA, LOW);
      digitalWrite(dispB, HIGH);
      digitalWrite(dispC, HIGH);
      digitalWrite(dispD, LOW);
      digitalWrite(dispE, LOW);
      digitalWrite(dispF, HIGH);
      digitalWrite(dispG, HIGH);
      break;
    case 5:
      digitalWrite(dispA, HIGH);
      digitalWrite(dispB, LOW);
      digitalWrite(dispC, HIGH);
      digitalWrite(dispD, HIGH);
      digitalWrite(dispE, LOW);
      digitalWrite(dispF, HIGH);
      digitalWrite(dispG, HIGH);
      break;
    case 6:
      digitalWrite(dispA, HIGH);
      digitalWrite(dispB, LOW);
      digitalWrite(dispC, HIGH);
      digitalWrite(dispD, HIGH);
      digitalWrite(dispE, HIGH);
      digitalWrite(dispF, HIGH);
      digitalWrite(dispG, HIGH);
      break;
    case 7:
      digitalWrite(dispA, HIGH);
      digitalWrite(dispB, HIGH);
      digitalWrite(dispC, HIGH);
      digitalWrite(dispD, LOW);
      digitalWrite(dispE, LOW);
      digitalWrite(dispF, LOW);
      digitalWrite(dispG, LOW);
      break;
    case 8:
      digitalWrite(dispA, HIGH);
      digitalWrite(dispB, HIGH);
      digitalWrite(dispC, HIGH);
      digitalWrite(dispD, HIGH);
      digitalWrite(dispE, HIGH);
      digitalWrite(dispF, HIGH);
      digitalWrite(dispG, HIGH);
      break;
    case 9:
      digitalWrite(dispA, HIGH);
      digitalWrite(dispB, HIGH);
      digitalWrite(dispC, HIGH);
      digitalWrite(dispD, HIGH);
      digitalWrite(dispE, LOW);
      digitalWrite(dispF, HIGH);
      digitalWrite(dispG, HIGH);
      break;
    case 10:
      digitalWrite(dispA, HIGH);
      digitalWrite(dispB, HIGH);
      digitalWrite(dispC, HIGH);
      digitalWrite(dispD, HIGH);
      digitalWrite(dispE, HIGH);
      digitalWrite(dispF, HIGH);
      digitalWrite(dispG, LOW);
      break;
    default:
      digitalWrite(dispA, LOW);
      digitalWrite(dispB, LOW);
      digitalWrite(dispC, LOW);
      digitalWrite(dispD, LOW);
      digitalWrite(dispE, LOW);
      digitalWrite(dispF, LOW);
      digitalWrite(dispG, LOW);
  }
}