debug code

src/mainclass.cpp

             return false;
           pifacedigital_write_reg(opt == 'u' ? up_pin(arg) : down_pin(arg),
             OUTPUT, get_current_device());
-          std::cout << get_pins() << std::endl;
+          std::cout << std::hex << (int)get_pins() << std::endl;
           return true;
           });
     }