text: #include "input.h"
  #include <Key.h>
  #include <Keypad.h>
  
  namespace Input
  {
      const byte ROWS = 4; // four rows
      const byte COLS = 3; // three columns
      const char keys[ ROWS ][ COLS ] = {
          { '1', '2', '3' }, //
          { '4', '5', '6' }, //
          { '7', '8', '9' }, //
          { '#', '0', '*' }  //
      };
      const byte rowPins[ ROWS ] = { 5, 6, 9, 10 }; // connect to the row pinouts of the keypad
      const byte colPins[ COLS ] = { 11, 12, 13 };  // connect to the column pinouts of the keypad
  
      Keypad keypad = Keypad( makeKeymap( keys ), rowPins, colPins, ROWS, COLS );
  
  
      void Scan()
      {
          char key = keypad.getKey();
  
          if( key != NO_KEY )
          {
              Serial.println( key );
          }
      }
  }