calculadora.ino

#include <LiquidCrystal.h>
#include <Keypad.h>

LiquidCrystal lcd(0,1,2,3,4,5);
const byte ROWS = 4;
const byte COLS = 4;

char keys [ROWS] [COLS] = {
    {'1','2','3','+'},
    {'4','5','6','-'},
    {'7','8','9','*'},
    {'C','0','=','/'}
};

byte rowPins[ROWS] = {A0,A1,11,10};
byte colPins[COLS] = {9,8,7,6};

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

boolean presentValue = false;
boolean next = false;
boolean final = false;
String num1, num2;
int answer;
char op;

void setup(){
    lcd.begin(16,2);
    lcd.setCursor(0,0);
    lcd.print("   Circuitos   ");
    lcd.setCursor(0,1);
    lcd.print("  Calculadora  ");
    delay(3000);
    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("   Hecho Por   ");
    lcd.setCursor(0,1);
    lcd.print("  Carlos Osuna ");
    delay(3000);
    lcd.clear();
} 

void loop(){
    char key = Teclado.getKey();
    if (key){

        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);
                lcd.print(num1);
            }else{
                num2 = num2 + key;
                int numLength = num2.length();
                lcd.setCursor(15-numLength,1);
                lcd.print(num2);
                final = true;
            }
        }
        else if (presentValue == false && key != NO_KEY && (key =='/'||key=='*'||key=='+'||key == '-')){
            if (presentValue == false){
                presentValue = true;
                op=key;
                lcd.setCursor(15,0);
                lcd.print(op);
            }
        }
        else if (final== true && key != NO_KEY && key=='='){
            if (op =='+'){
                answer = num1.toInt() + num2.toInt();
            }
            else if (op =='-'){
                answer = num1.toInt() - num2.toInt();
            }
            else if (op =='*'){
                answer = num1.toInt() * num2.toInt();
            }
            else if (op =='/'){
                answer = num1.toInt() / num2.toInt();
            }
            lcd.clear();
            lcd.setCursor(15,0);
            lcd.autoscroll();
            lcd.print(answer);
            lcd.noAutoscroll();
        }
        else if (key != NO_KEY && key == 'C'){
            lcd.clear();
            presentValue = false;
            final = false; 
            num1 =' ';
            num2 =' ';
            answer = 0;
            op = ' ';
        }
    }
}