C++ Libusb-ubuntu-Psoc5。libusb\u打开\u设备\u，带\u vid\u pid返回0

第四学期我在做一个电力工程项目，编程不是我的强项。我一直在使用一个用C++编写的Linux终端程序之间的通信。终端代码为：

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问题是

libusb\u open\u device\u with\u vid\u pid（NULL，0x1111，0x2222）

每次都返回0，即使Linux操作系统可以识别该设备。操作系统是相关的

#include <iostream>
#include "libusb-1.0/libusb.h"
#include "usb.h"
#include <time.h>

using namespace std;

union USB_DATA
{
    unsigned char USB_ARRAY[1200];

    int DirectionOfPower;
    int menu;

    float Voltage;
    float Current;
    float Temperature;

    float PowerFactor;
    float DistortionPowerFactor;
    float Amplitude_Of_Harmonics[1001];
    float Regulate_To;
};

union USB_DATA USB_;

/*
void error(string s, int err)
{
    cout << s " ERROR: " << libusb_error_name(err) << endl;
    exit(err);
}


*/


int main()
{
    int transfer_size;
    int err;
    float Reg_To;

    // Device Handle
    libusb_device_handle* dev;

    // Initialize libusb with default context
    libusb_init(NULL);

    // Open Device VID = 0x1111, PID = 0x2222 with the default libusb context
    dev = libusb_open_device_with_vid_pid( NULL, 0x1111, 0x2222 );

    // If device is null, we didn't find it
    /*
        if (dev == NULL)
        {
            cout << "Device not found, exiting." << endl;
            return -1;
        }

        int k = 0;
        while (dev == NULL)
        {
            cout << "Device not found, trying again." << " " << k << endl;
            //sleep(1);
            k = k+1;
        }
    */

    // Claim interface 0 on the device. Here we te the operation system that wewan this device
    libusb_claim_interface(dev, 0);
    libusb_detach_kernel_driver(dev, 0);
    // Set alternate setting 0 on interface 0
    libusb_set_interface_alt_setting(dev, 0, 0);

    while(true)
    {
        cout << "Welcome to Spaendingsregulering!" << endl;
        cout << endl;
        cout << "MENU" << endl;
        cout << "Indtast nummer for navigation" << endl;
        cout << "1. Indsaet driftsparametre " << endl;
        cout << "2. Analyser harmoniske " << endl;
        cout << "3. Fremvis data " << endl;

        while(true)
        {
            cin >> USB_.menu;
            if(cin.good())
                break;
            cin.clear();
        }

        /*
                err = libusb_bulk_transfer(dev, 0x02, USB_.USB_ARRAY, sizeof(union USB_), &transfer_size, 1000);
                if( err )
                    error( "Bulk OUT Transfer Failed!", err);

                err = libusb_bulk_transfer(dev, 0x81, USB_.USB_ARRAY, sizeof(union USB_), &transfer_size, 1000);
                if( err )
                    error( "Bulk IN Transfer Failed!", err);
        */

        if(USB_.menu == 1)
            while(true)
            {
                cout << "Indsaet oensket spaending" << endl;
                cout << "Indtast 999 for at vende tilbage til hovedmenuen" << endl;
                cin >> Reg_To;
                cout << endl;
                if(Reg_To == 999)
                {
                    break;
                }
                USB_.Regulate_To = Reg_To;

                cout << "=======================" << endl;
                cout << "Saetter oensket spaending til:" << " " << USB_.Regulate_To << "V" << endl;
                cout << "=======================" << endl;
                cout <<  endl;
                cout << "Vender tilbage til hovedmenu" << endl;
                cout << "..." << endl;
                cout <<  endl;
                if(cin.good())
                    break;
                cin.clear();
                }
            }
    }

#包括
#包括“libusb-1.0/libusb.h”
#包括“usb.h”
#包括
使用名称空间std；
联合USB_数据
{
无符号字符USB_阵列[1200]；
int定向电源；
int菜单；
浮充电压；
浮充电流；
浮子温度；
浮动功率因数；
浮动失真功率因数；
_谐波的浮动幅度_[1001]；
浮动调节到；
};
联合USB_数据USB_；
/*
无效错误（字符串s，整数错误）
{
cout
libusb\u open\u device\u with\u vid\u pid
将查找和打开结合在一起，并且不返回错误代码。如果您确定设备在那里，是否已检查您是否有权读取/写入该设备？您也可以。
-莱亚兹

谢谢！成功了！我忘了使用sudo..新手错误-ğrıEsen
libusb_open_device_with_vid_pid
将查找和打开结合在一起，不返回错误代码。如果你确定设备在那里，你检查过你有读/写它的权限吗？你也可以。谢谢！成功了！我忘了使用sudo..ro奥基错误