C++:与 Arduino 的串行接口(interface)

Question

我一直在尝试通过串行端口和下面的 C++ 代码与 Arduino 通信。

唯一的问题是:它总是返回一个invalid_handle_value。

我到处都看了，所有人都在使用某种相同的代码......除了它对他们有用。

P.S:Arduino 在 COM15 上。此代码适用于端口 COM4(蓝牙)。

代码

#include "SerialClass.h"

Serial::Serial(char *portName)
{
    //We're not yet connected
    this->connected = false;

    //Try to connect to the given port throuh CreateFile
    this->hSerial = CreateFile(portName,
        /*GENERIC_READ | GENERIC_WRITE,
        0,
        NULL,
        OPEN_EXISTING,
        FILE_ATTRIBUTE_NORMAL,
        NULL);*/

        GENERIC_READ | GENERIC_WRITE,
        0,
        0,
        OPEN_EXISTING,
        FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED,
        0);

    //Check if the connection was successful.
    if (this->hSerial==INVALID_HANDLE_VALUE)
    {
        //If not success full display an Error.
        if (GetLastError()==ERROR_FILE_NOT_FOUND){

            //Print Error if neccessary
            printf("ERROR: Handle was not attached. Reason: %s not available.\n", portName);

        }
        else
        {
            printf("ERROR!!!");
        }
    }
    else
    {
        //If connected we try to set the comm parameters
        DCB dcbSerialParams = {0};

        //Try to get the current
        if (!GetCommState(this->hSerial, &dcbSerialParams))
        {
            //If impossible, show an error
            printf("failed to get current serial parameters!");
        }
        else
        {
            //Define serial connection parameters for the arduino board
            dcbSerialParams.BaudRate=CBR_9600;
            dcbSerialParams.ByteSize=8;
            dcbSerialParams.StopBits=ONESTOPBIT;
            dcbSerialParams.Parity=NOPARITY;

            //Set the parameters and check for their proper application
            if (!SetCommState(hSerial, &dcbSerialParams))
            {
               printf("ALERT: Could not set Serial Port parameters");
            }
            else
            {
                //If everything went fine we're connected
                this->connected = true;
                //We wait 2s as the arduino board will be reseting
                Sleep(ARDUINO_WAIT_TIME);
            }
        }
    }
}

Serial::~Serial()
{
    //Check if we are connected before trying to disconnect
    if (this->connected)
    {
        //We're no longer connected
        this->connected = false;
        //Close the serial handler
        CloseHandle(this->hSerial);
    }
}

int Serial::ReadData(char *buffer, unsigned int nbChar)
{
    //Number of bytes we'll have read
    DWORD bytesRead;
    //Number of bytes we'll really ask to read
    unsigned int toRead;

    //Use the ClearCommError function to get status info on the Serial port
    ClearCommError(this->hSerial, &this->errors, &this->status);

    //Check if there is something to read
    if (this->status.cbInQue>0)
    {
        //If there is we check if there is enough data to read the required number
        //of characters, if not we'll read only the available characters to prevent
        //locking of the application.
        if (this->status.cbInQue>nbChar)
        {
            toRead = nbChar;
        }
        else
        {
            toRead = this->status.cbInQue;
        }

        //Try to read the require number of chars, and return the number of read bytes on success
        if (ReadFile(this->hSerial, buffer, toRead, &bytesRead, NULL) && bytesRead != 0)
        {
            return bytesRead;
        }

    }

    //If nothing has been read, or that an error was detected return -1
    return -1;
}


bool Serial::WriteData(char *buffer, unsigned int nbChar)
{
    DWORD bytesSend;

    //Try to write the buffer on the Serial port
    if (!WriteFile(this->hSerial, (void *)buffer, nbChar, &bytesSend, 0))
    {
        //In case it don't work get comm error and return false
        ClearCommError(this->hSerial, &this->errors, &this->status);

        return false;
    }
    else
        return true;
}

bool Serial::IsConnected()
{
    //Simply return the connection status
    return this->connected;
}

int main() {
    Serial serial("COM15");
    if (serial.IsConnected()){
        serial.WriteData("1",1);
        printf("\nData sent successfully!\n");
    }
    system("pause");
    return 0;
}

Answer 1

尝试使用文件名 "\\\\.\\COM15"(参见 http://support.microsoft.com/kb/115831)。