Create calc

Author: Akul-Verma

calc

@@ -0,0 +1,212 @@
+
+// calculator
+
+#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] = {13,12,11,10};
+
+byte colPins[COLS] = {9,8,7,6};
+
+
+
+Keypad myKeypad = 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(" AKUL VERMA JI");
+
+  lcd.setCursor(0,1);
+
+  lcd.print("   Calculator");
+
+  delay(3000);
+
+  lcd.clear();
+
+  lcd.setCursor(0,0);
+
+  lcd.print("       by     ");
+
+  lcd.setCursor(0,1);
+
+  lcd.print("  AKUL VERMA JI"    );
+
+  delay(3000);
+
+  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(15 - numLength, 0); //to adjust one whitespace for operator
+
+      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 = ' ';
+
+  }
+
+}