Added arduino files

C++/Arduino/Serial_Keypad/Serial_Keypad.ino

@@ -0,0 +1,31 @@
+#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','#','D'}
+};
+
+byte rowPins[ROWS] = {5, 4, 3, 2};
+byte colPins[COLS] = {9, 8, 7, 6};
+
+const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
+LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
+
+Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );
+
+void setup(){
+   lcd.begin(16, 2);
+   Serial.begin(9600);
+}
+  
+void loop(){
+  char key = keypad.getKey();
+  
+  if (key){
+    Serial.println(key);
+  }
+}