ALGORITMA SWITCH CASE BERBASIS ARDUINO

Skematik Rangkaian 

Komponen yang dibutuhkan

1.  Arduino Uno

2.  Keypad

3. LM016L 16x2

4.  Power

5.  Remote 8 bit

Sketch Arduino

#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 20, 2);

#include <Keypad.h>
const byte ROWS = 4;
const byte COLS = 4;

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

Keypad myKeypad = Keypad(
makeKeymap(keys), rowPins, colPins,
ROWS, COLS );
float presentValue = false;
float next = false;float final = false;
String num1, num2; String answer = "0";
char op;

void setup(){
  lcd.init();
  lcd.backlight();
  lcd.setCursor(5,0);
  lcd.print("UNIT 5");
  lcd.setCursor(3,1);
  lcd.print("Calculator");
  delay(1000);
  lcd.clear();
}
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(0, 0);
      lcd.print(num1);
    }
    else{
      num2 = num2 + key;
      int numLength = num2.length();
      int numLength1 = num1.length();
      lcd.setCursor(1 + numLength1, 0);
      lcd.print(num2);
      final = true;
    }
  }
  else if (presentValue == false && key !=
  NO_KEY && (key == '/' || key == '*' || key
  == '-' || key == '+')){
    if (presentValue == false){
      int numLength = num1.length();
      presentValue = true;op = key;
      lcd.setCursor(0 + numLength, 0);
      lcd.print(op);
    }
  }
  else if (final == true && key != NO_KEY && key == '=') {
    switch (op){
      case '+':
        answer = num1.toFloat() + num2.toFloat();
        break;
      case'-' :
        answer = num1.toFloat() - num2.toFloat();
        break;
      case'*' :
      answer = num1.toFloat() * num2.toFloat();
      break;
      case'/':
      answer = num1.toFloat() / num2.toFloat();
      break;
    }
    lcd.clear();
    lcd.setCursor(16, 1);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 = ' ';
  }
}

Video Simulasi