test بالوت حاسبة

#include <Keypad.h>

const byte ROWS = 4;
const byte COLS = 4;

char keys [ROWS] [COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', '+'},
  {'C', '0', '=', '-'}
};
byte rowPins[ROWS] = {9,8,7,6};
byte colPins[COLS] = {5,4,3,2};

Keypad myKeypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );

boolean presentValue = false;

boolean next = false;

boolean final = false;

String num1, num2;

int answer;
int AValue=0;
int BValue=0;
char op;

void setup()
{
  Serial.begin(9600);
  delay(3000);
}

void loop(){

  char key = myKeypad.getKey();

  if (key != NO_KEY && (key=='1'||key=='2'||key=='3'||key=='4'||key=='5'||key=='6'||key=='7'||key=='8'||key=='9'||key=='0'))
  {
    if (presentValue != true)
    {
      num1 = num1 + key;
      int numLength = num1.length();
      //lcd.setCursor(15 - numLength, 0); //to adjust one whitespace for operator
      //lcd.print(num1);
      Serial.print(num1);
    }
    else
    {
      num2 = num2 + key;
      int numLength = num2.length();
      //lcd.setCursor(15 - numLength, 1);
      //lcd.print(num2);
      Serial.print(num2);
      final = true;
    }
  }

  else if (presentValue == false && key != NO_KEY && (key == '-' || key == '+'))
  {
    if (presentValue == false)
    {
      presentValue = true;
      op = key;
      //lcd.setCursor(15,0);
      //lcd.print(op);
      Serial.print(op);
    }
  }

  else if (final == true && key != NO_KEY && (key == 'A' || key == 'B')){
    if (op == '+'){
      answer = num1.toInt() + num2.toInt();
      if(key == 'A'){
        AValue = AValue + answer;
      }
      else{
        BValue = BValue + answer;
      }
    }
    else if (op == '-'){
      answer = num1.toInt() - num2.toInt();
      if(key == 'A'){
        AValue = AValue - answer;
      }
      else{
        BValue = BValue - answer;
      }
    }

      //lcd.clear();
      //lcd.setCursor(15,0);
      //lcd.autoscroll();
      //lcd.print(answer);
      Serial.print(" = ");
      Serial.println(answer);
      Serial.print("A = ");
      Serial.println(AValue);
      Serial.print("B = ");
      Serial.println(BValue);
      presentValue = false;
      final = false;
      num1 = "";
      num2 = "";
      answer = 0;
      op = ' ';
      //lcd.noAutoscroll();
  }
  else if (key != NO_KEY && key == 'C'){
    //lcd.clear();
    Serial.println("--------------");
    presentValue = false;
    final = false;
    num1 = "";
    num2 = "";
    answer = 0;
    op = ' ';
  }
}