Question

好吧，我已经参加了这个计划大概四个小时了。我一直试图创建一个小程序来读取我的arduino Uno通过串口吐出的内容。

我觉得奇怪的是，该程序仅在我推出了arduino IDE的内置串行监视器之后才能工作。也许这是正确初始化端口的问题？

如果有人可以帮助我，我会非常感激。该程序似乎在ReadFile期间挂起，所以可能存在权限问题......

 

#include Windows.h>
    #include stdio.h>
    #include tchar.h>//Removed to allow for stackoverflow format
    void printCommState(DCB d);

int main() {
    DCB dcb = { 0 };
    HANDLE hPort;
    BOOL success;
    TCHAR *commPort = TEXT("COM3");
    char buffer[40] = { 0 };
    DWORD dwBytesRead = 0;
    DWORD dwBytesWrite = 0;
    int l;
    /*COMMTIMEOUTS cTimeOut;
    cTimeOut.ReadIntervalTimeout = 50;
    cTimeOut.ReadTotalTimeoutConstant = 50;
    cTimeOut.ReadTotalTimeoutMultiplier = 10;
    cTimeOut.WriteTotalTimeoutConstant = 50;
    cTimeOut.WriteTotalTimeoutMultiplier = 10;*/
    dcb.DCBlength = sizeof(DCB);
    dcb.BaudRate = CBR_9600;//Found on microsofts website
    dcb.ByteSize = DATABITS_8;// standardized number?
    dcb.Parity = NOPARITY;// found in comp management
    dcb.StopBits = 1;
    /*dcb.fBinary = 1;
    dcb.fDtrControl = 1;
    dcb.fTXContinueOnXoff = 1;
    dcb.fRtsControl = 1;
    dcb.XonLim = 2048;
    dcb.XoffLim = 512;
    dcb.XoffChar = 2;*/
    //dcb.fDtrControl = DTR_CONTROL_DISABLE;//maybe unnecessary?

    printCommState(dcb);

    hPort = CreateFile(commPort, // This comm port is defined by TCHAR so that we can use TEXT() LPFILENAME
        GENERIC_READ | GENERIC_WRITE,//DesiredAccess
        0,//dwShareMode
        NULL,//LPSecurity
        CREATE_NEW| OPEN_EXISTING,//dwCreationDisposition
        0,//Flags and attributes
        NULL);//hTemplateFile

    if (hPort == INVALID_HANDLE_VALUE) {
        printf("CreateFile failed with the error %d.\n", GetLastError());
        scanf_s("%d", &l);
        return 1;
    }


    success = GetCommState(hPort, &dcb);

    if (!success) {
        printf("GetCommState failed with the error %d.\n ", GetLastError());
        scanf_s("%d", &l);
        return 2;
    }

    success = SetCommState(hPort, &dcb);
    if (!success) {
        printf("SetCommState failed with error %d.\n", GetLastError());
        scanf_s("%d", &l);
        return 3;
    }
    /*TIME TO READ STUFF*/
        while (GetCommState(hPort, &dcb)) {
        printf("We're in the while statement\n");
         //+=+=+=+=+=+POSSIBLE PROBLEM?
                 if (ReadFile(hPort, buffer, 39, &dwBytesRead, NULL))     {
    //hFile,lpBuffer,NumberofBytesToRead,LPnumberofbytestoread,lpOverlapped
                printf("We're in the ifReadFile Statement!\n");
                for (int j = 0; j < sizeof(buffer); j++) {
                printf("in the for loop!\n");
                printf("%c", buffer[j]);

            }
            printf("\n");
        }
        if (!ReadFile(hPort, &buffer, 39, &dwBytesRead, NULL)) {
            printf("Error with ReadFile %d\n.", GetLastError());
        }

    }

    scanf_s("%d", &l);
    CloseHandle(hPort);


    return 0;
    }
    void printCommState(DCB d) {
        printf("\nBaudRate:  %d\tByteSize:  %d\tParity:  %d\tStopBits:  %d\n",
            d.BaudRate,
            d.ByteSize,
            d.Parity,
            d.StopBits);
    }

Answer 1

问题在于代码的GetCommState行

GetCommState code function

这里我们将DCB设置为该函数返回的设置，因此通过添加另一个DCB（例如dcbRecieving，例如）作为一个错误捕获设备并让GetCommState指向其他DCB，我们可以保持我们的错误捕获DCB并将我们的原始设置为另一个，或在if语句后设置新参数。

无论如何，非常感谢！

从C中的串口读取，有ReadFile问题可能吗？

1 个答案: