CSerialPort

More often than not, the CserialPort class relies on C++ exceptions to indicate errors and hence, can help determine whether a certain hardware is malfunctioning or the issue is mostly software-related. After all, serial ports provide an easy way to communicate with many types of hardware and your main machine and are very simple to use among peripherals, especially in the do-it-yourself projects.
For instance, if you were to setup Arduino or a similar platform with a built-in serial communication, you are unlikely to have any problems. In this case, you need your platform to communicate with the computer so that you can access the interactive output. Then again, depending on the operating system on your machine, you may be in the unpleasant situation of having the ports busy or inaccessible due to various reasons.
The CSerialPort was designed to be an MFC class to support access to the Win32 APIs dealing with serial ports. The library is Unicode enabled and hence, you are unlikely to have any issues integrating with the MFC class using a CSERIALPORT_MFC_EXTENSIONS preprocessor value. Moreover, according to the developer, the code compiles cleanly at warning level 4 and supports a wide variety of serial ports, including the overlapped, call-back and blocking usage models.