Issue with receiving data about ardity

[dwilches]

The provided code is missing the declaration of fromVR1, could you attach the actual code snippet you are running?

[hnryirawan]

Here are the codes. There are some commented parts that I'm currently not using

#include "stdafx.h"
#include <stdio.h>
#include <tchar.h>
#include <string>
#include <iostream>

#include <cstdlib>

#include "SerialClass.h" // Library described above

using namespace std;

int main() {
	Serial* VR = new Serial("\\\\.\\COM7");
//	Serial* Receiver = new Serial("\\\\.\\COM8");
	int input;
	char toVR1[] = "K\n";
	char toVR2[3];
	char fromVR1[2];
	char fromVR2[2];

	if (VR->IsConnected())
		printf("VR is connected\n\n");

/*	if (Receiver->IsConnected())
		printf("Receiver connected\n\n");*/

	toVR2[0] = '1';
	toVR2[1] = '\n';
	toVR2[2] = '\0';

	while (true) 
	{
		cout << "please enter 0 for send, 1 for read, 2 for receive, and 3 for write receiver" << '\n';
		cin >> input;
		if (input == 0)
		{
			cout << toVR1;
			VR->WriteData(toVR1, 3);
		}
		else if (input == 1)
		{
			VR->ReadData(fromVR1, 2);
			cout << fromVR1[0] << '\n';
		}
/*		else if (input == 2)
		{
			Receiver->ReadData(fromVR2,2);
			cout << fromVR2 << '\n';
		}
		else if (input == 3)
			Receiver->WriteData(toVR2, 2);*/
	}
	return 0;
}

and here is the cpp files that handles serial connection

#include "stdafx.h"
#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);

    //Check if the connection was successfull
    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;
}

[hnryirawan]

for reference, here is the class header files

#ifndef SERIALCLASS_H_INCLUDED
#define SERIALCLASS_H_INCLUDED

#define ARDUINO_WAIT_TIME 2000

#include <windows.h>
#include <stdio.h>
#include <stdlib.h>

class Serial
{
    private:
        //Serial comm handler
        HANDLE hSerial;
        //Connection status
        bool connected;
        //Get various information about the connection
        COMSTAT status;
        //Keep track of last error
        DWORD errors;

    public:
        //Initialize Serial communication with the given COM port
        Serial(char *portName);
        //Close the connection
        //NOTA: for some reason you can't connect again before exiting
        //the program and running it again
        ~Serial();
        //Read data in a buffer, if nbChar is greater than the
        //maximum number of bytes available, it will return only the
        //bytes available. The function return -1 when nothing could
        //be read, the number of bytes actually read.
        int ReadData(char *buffer, unsigned int nbChar);
        //Writes data from a buffer through the Serial connection
        //return true on success.
        bool WriteData(char *buffer, unsigned int nbChar);
        //Check if we are actually connected
        bool IsConnected();


};

#endif // SERIALCLASS_H_INCLUDED

[dwilches]

Hi,

I gave it a quick look and the first problem I found was that fromVR1 is declared as a buffer of 2 bytes, but later when you try to print it out with cout you are expecting it to have a null-terminator in the 3rd byte, which is outside the buffer.

I'm not familiar with that software you mentioned you are using (Eltima nor HDD) so I cannot be of much assistance here.