Serial Port (RS -232) Connection in C++

iammurtaza picture iammurtaza · Apr 3, 2013 · Viewed 144.8k times · Source

I have done serial port RS-232 connection in C++ using 16-bit compiler (I was using Turbo C++ IDE). It included header file bios.h which contain all the required functions for reading values from the port. Now I want to read value from serial port using C++ 32-bit Mingw compiler. I am using Dev CPP as my IDE. Here I could not find bios.h. Are there any special header files available for this purpose in Mingw? I am using 32-bit compiler now because in my college project I got to use Exception handling which I guess is not supported in Turbo C. Please help me out.

Answer

ollo picture ollo · Apr 3, 2013

Please take a look here:

1) You can use this with Windows (incl. MinGW) as well as Linux. Alternative you can only use the code as an example.

2) Step-by-step tutorial how to use serial ports on windows

3) You can use this literally on MinGW

Here's some very, very simple code (without any error handling or settings):

#include <windows.h>

/* ... */


// Open serial port
HANDLE serialHandle;

serialHandle = CreateFile("\\\\.\\COM1", GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);

// Do some basic settings
DCB serialParams = { 0 };
serialParams.DCBlength = sizeof(serialParams);

GetCommState(serialHandle, &serialParams);
serialParams.BaudRate = baudrate;
serialParams.ByteSize = byteSize;
serialParams.StopBits = stopBits;
serialParams.Parity = parity;
SetCommState(serialHandle, &serialParams);

// Set timeouts
COMMTIMEOUTS timeout = { 0 };
timeout.ReadIntervalTimeout = 50;
timeout.ReadTotalTimeoutConstant = 50;
timeout.ReadTotalTimeoutMultiplier = 50;
timeout.WriteTotalTimeoutConstant = 50;
timeout.WriteTotalTimeoutMultiplier = 10;

SetCommTimeouts(serialHandle, &timeout);

Now you can use WriteFile() / ReadFile() to write / read bytes. Don't forget to close your connection:

CloseHandle(serialHandle);