Работа с СОМ-портом

WriteFile(hComPort, buff, buffSize, &bytesWritten, NULL);

PurgeComm(hComPort, PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR | PURGE_RXCLEAR);

COMMTIMEOUTS timeOuts;
 
GetCommTimeouts(hPort, &timeOuts);
 
timeOuts.ReadIntervalTimeout = MAXDWORD;
timeOuts.ReadTotalTimeoutMultiplier = 0;
timeOuts.ReadTotalTimeoutConstant = 0;
timeOuts.WriteTotalTimeoutMultiplier = 0;
timeOuts.WriteTotalTimeoutConstant = 0;
 
if (!SetCommTimeouts(hPort, &timeOuts))

WaitCommEvent(hPort, &dwMask, NULL);
ClearCommError(hPort, &dwError, &comstat);
        
dwRead = comstat.cbInQue;
 
if (dwRead > 0)
{
    ReadFile(hPort, buf, dwRead, &dwRead, NULL);
 
    PurgeComm(hPort, PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR | PURGE_RXCLEAR);
        
    for (int i = 0; i < (int)dwRead; i++)
        printf_s("Byte read #%d: %u\n", i, buf[i]);
}

BOOL WINAPI ReadFile(
  _In_         HANDLE hFile,
  _Out_        LPVOID lpBuffer,
  _In_         DWORD nNumberOfBytesToRead,
  _Out_opt_    LPDWORD lpNumberOfBytesRead,
  _Inout_opt_  LPOVERLAPPED lpOverlapped
);

DWORD dwRead = comstat.cbInQue, dwGot = 0;
ReadFile(hPort, buf, dwRead, &dwGot, NULL);

DWORD dwGot = 0;
 
Sleep(5000);
ReadFile(hPort, buf, 60, &dwGot, NULL);

BYTE* buf = 0;
 
while (!terminated)
{
    if (!buf) buf = new BYTE[bufferSize];
    else
    {
        delete[] buf;
        buf = new BYTE[bufferSize];
    }
 
    // ...
}