Reading USB Values

[therealjag]

Hey there, I have a program to read usb values in windows but Im looking to modify this for SuSe Linux. My current code is shown below:

// readusbdong.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <iostream>
#include <string.h>
#include <windows.h>
#include "ftd2xx.h" // Needs to go after others

using namespace std;

// Function Prototypes
void showUsage();

// Some global variables
bool bMask(false);            // Should we return all 8 bits?
bool bEcho(false);            // Should we also echo to screen?

int main(int argc, char* argv[])
{
#define READ_COMMAND 0x80
#define READ_LENGTH  4
#define WRITE_LENGTH 1


    // First see if we have any switches
    int i=1;
    while (i < argc)
    {
        if (strcmp("/mask", argv[i]) == 0)
        {
            // Mask specified
            bMask = true;
            i++;
        }
        else if (strcmp("/echo", argv[i]) == 0)
        {
            // Echo specified
            bEcho = true;
            i++;
        }
        else
        {
            // Don't understand the parameter
            showUsage();
            return 0;
        }
    } // Wend

    // Now try to read dongle

    FT_STATUS ftStatus;
    FT_HANDLE ftHandle;

    ftStatus = FT_OpenEx (
                "FT245R USB FIFO",
                FT_OPEN_BY_DESCRIPTION,
                &ftHandle);

    if (ftStatus != FT_OK)
    {
        cout << "Failed to obtain file handle to device FT245R USB FIFO" << endl;
        return 255; // As we use this as a legit return, need to return illegal
                    // value
    }


    DWORD BytesWritten;

    char WriteBuffer [WRITE_LENGTH];


    WriteBuffer [0] = (char) READ_COMMAND; // 1st byte, read command

    ftStatus = FT_Write (
                ftHandle,
                &WriteBuffer,
                WRITE_LENGTH, // Bytes to write
                &BytesWritten);

    if ( (ftStatus != FT_OK) || (BytesWritten != WRITE_LENGTH) )
    {
        cout << "Failed to write" << endl;
        return 255; // As we use this as a legit return, need to return illegal
                    // value
    }


    Sleep (1) ; // Delay 1 ms


    DWORD BytesRead;

    char ReadBuffer [READ_LENGTH];

    ftStatus = FT_Read (
                ftHandle,
                &ReadBuffer,
                READ_LENGTH, // Bytes to read
                &BytesRead);

    if ( (ftStatus != FT_OK) || (BytesRead != READ_LENGTH) )
    {
        cout << "Failed to read" << endl;
        return 255; // As we use this as a legit return, need to return illegal
                    // value
    }


    char XOR_Result = ReadBuffer [0];

    XOR_Result ^= ReadBuffer [1];
    XOR_Result ^= ReadBuffer [2];
    XOR_Result ^= ReadBuffer [3];

    if (XOR_Result != 0)
    {
        cout << "Failed checksum" << endl;
        return 255; // As we use this as a legit return, need to return illegal
                    // value
    }


    ftStatus = FT_Close (
                ftHandle);

    if (ftStatus != FT_OK)
    {
        cout << "Failed to close" << endl;
        return 255; // As we use this as a legit return, need to return illegal
                    // value
    }



    unsigned char nDongleValue = (unsigned char) ReadBuffer [1]; // 2nd byte


    // OK, if we've arrived here, we have legit values
    if(bMask)
    {
        // Mask out top two bits
        nDongleValue &= 63;
    }

    if(bEcho)
    {
        // Echo specified, so print to console
        cout << "Dongle id is " << (int)nDongleValue << endl;
    }

    // All done, just return the value
    return nDongleValue;
}

void showUsage()
{
    cout << "readusbdong: Sets %ERROR_LEVEL% to value of USB Dongle" << endl;
    cout << "   usage: readusbdong [/full] [/echo]" << endl;
    cout << "   where /mask returns all 8 bits, default is lower 6" << endl;
    cout << "         /echo also prints value to console" << endl;
    return;
}

Is there an equivalent way to access the USB port in SuSe Linux?

Cheers, Jag

[gogalthorp]

All devices in Linux show up in the /dev directory as files just open and use accordingly.

[therealjag]

Ah ok, I came across this directory before but had no clue as to what it was? How would I go about using one of these files?

[gogalthorp]

It's a file just open it like any other file.