我正在尝试使用libusb-1.0和qtubs库来访问usb设备。它是一个简单的大容量设备,在我做一些更新之前就可以工作了。
目前我使用
Linux nadhh.fritz.box 4.11.8-200.fc25.x86_64 #1 SMP Thu Jun 29 16:13:56 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
我是以用户还是根用户身份运行并不重要,因为udev会将设备设置为组用户和权限666
[timestamp] [threadID] facility level [function call] <message>
--------------------------------------------------------------------------------
[ 0.012281] [00000fc6] libusb: error [op_get_configuration] device unconfigured
Type:1, cat:default, file:../src/qlibusb.cpp, line:114, f:virtual qint32 QUsbDevice::open(), msg:Cannot Claim Interface
Type:1, cat:default, file:../src/qlibusb.cpp, line:168, f:void QUsbDevice::printUsbError(int), msg:libusb Error: Entity not found
[ 0.951403] [00000fc6] libusb: warning [libusb_exit] application left some devices open
我是以用户还是根用户身份运行并不重要,因为udev会将设备设置为组用户和权限666
欢迎任何提示
真诚的于尔根
守则
取自
qtubs公司
qt的跨平台usb库。
依赖于libusb-1.0。
特征
散装运输
设备插入/移除检测
设备搜索
待办事项
中断传输
等时传输
用法
文档还不完整,您可以同时查看示例。
文档
doxygen文档可以在这里找到:http://fpoussin.github.io/doxygen/qtusb/
下载
ubuntu购电协议:https://launchpad.net/~fpoussin/+archive/ubuntu/ppa
Windows库即将推出。
标题
#ifndef USBEXAMPLE_H
#define USBEXAMPLE_H
#include <QObject>
#include <QUsb>
const quint8 USB_PIPE_IN = 0x81; /* Bulk output endpoint for responses */
const quint8 USB_PIPE_OUT = 0x01; /* Bulk input endpoint for commands */
const quint16 USB_TIMEOUT_MSEC = 300;
const quint16 vendor_id = 0x04e3;
const quint16 product_id= 0x0001;
class UsbExample : public QObject
{
Q_OBJECT
public:
explicit UsbExample(QObject *parent = 0);
~UsbExample(void);
void setupDevice(void);
bool openDevice(void);
bool closeDevice(void);
void read(QByteArray *buf);
void write(QByteArray *buf);
signals:
public slots:
private:
QUsbManager mUsbManager;
QUsbDevice* mUsbDev;
QtUsb::DeviceFilter mFilter;
QtUsb::DeviceConfig mConfig;
};
#endif // USBEXAMPLE_H
CPP公司
#include <iostream>
#include "usbexample.h"
using namespace std;
#ifdef interface
#undef interface
#endif
UsbExample::UsbExample(QObject *parent) : QObject(parent) {
this->setupDevice();
QByteArray send, recv;
send.append(".[]=R00[]=R01[]=R02$");
if (this->openDevice()) {
cerr << "Device open!" << endl;
this->write(&send);
this->read(&recv);
}
}
UsbExample::~UsbExample() { delete mUsbDev; }
void UsbExample::setupDevice() {
/* There are 2 ways of identifying devices depending on the platform.
* You can use both methods, only one will be taken into account.
*/
mUsbDev = new QUsbDevice();
mUsbDev->setDebug(true);
#if 1
// Bus 003 Device 004: ID 04e3:0001 Zilog, Inc.
mFilter.pid = 0x0001;
mFilter.vid = 0x04E3;
#else
mFilter.vid = 0x0c4b;
mFilter.pid = 0x0400;
#endif
//
mConfig.alternate = 0;
mConfig.config = 0;
mConfig.interface = 0;
mConfig.readEp = 0x81;
mConfig.writeEp = 0x02;
}
bool UsbExample::openDevice() {
cerr << "Opening" << endl;
QtUsb::DeviceStatus ds;
ds = mUsbManager.openDevice(mUsbDev, mFilter, mConfig);
if (ds == QtUsb::deviceOK) {
// Device is open
return true;
}
return false;
}
bool UsbExample::closeDevice() {
cerr << "Closing" << endl;
mUsbManager.closeDevice(mUsbDev);
return false;
}
void UsbExample::read(QByteArray *buf) { mUsbDev->read(buf, 1); }
void UsbExample::write(QByteArray *buf) { mUsbDev->write(buf, buf->size()); }
#include "usbexample.h"
#include <QCoreApplication>
#include <QTimer>
#include <iostream>
void customLogHandler(QtMsgType type, const QMessageLogContext& context,
const QString& msg)
{
// send the data to log file via the other thread
// emit writeToFile(type, context, msg);
// now output to debugger console
#ifdef Q_OS_WIN
OutputDebugString(text.toStdWString().c_str());
#else
std::cerr << "Type:" << type << ", cat:" << context.category << ", file:" << context.file
<< ", line:" << context.line
<< ", f:" << context.function << ", msg:" << msg.toStdString() << std::endl;
#endif
}
int main(int argc, char *argv[]) {
qInstallMessageHandler(&customLogHandler);
QCoreApplication a(argc, argv);
QTimer timer;
QObject::connect(&timer, SIGNAL(timeout()), &a, SLOT(quit()));
timer.setInterval(1000);
timer.setSingleShot(true);
timer.start();
UsbExample example;
return a.exec();
}
最佳答案
这是配置问题。在usb中,你必须遵守层次结构
设备描述符-配置描述符-接口描述符-终结点描述符
(http://www.beyondlogic.org/usbnutshell/usb1.shtml)
如果在配置级别上有错误,所有其他级别也会失败
很可能错误出现在以下代码中:
mConfig.alternate = 0;
mConfig.config = 0;
mConfig.interface = 0;
mConfig.readEp = 0x81;
mConfig.writeEp = 0x02;
问题是我不知道你的设备的usb树的结构,所以你必须这样做。您可以通过
lsusb -v
或usb-devices
获取结构,并在设备中搜索结构顺序“device-configuration-interface-endpoint”如果您有修改上述代码所需的信息(即更改接口索引、备用设置…)
源代码的关键部分是
int conf;
libusb_get_configuration(mDevHandle, &conf);
if (conf != mConfig.config) {
if (mDebug) qDebug("Configuration needs to be changed");
rc = libusb_set_configuration(mDevHandle, mConfig.config);
if (rc != 0) {
qWarning("Cannot Set Configuration");
this->printUsbError(rc);
return -3;
}
}
rc = libusb_claim_interface(mDevHandle, mConfig.interface);
if (rc != 0) {
qWarning("Cannot Claim Interface");
this->printUsbError(rc);
return -4;
}
来源:https://github.com/fpoussin/QtUsb/blob/master/src/qlibusb.cpp
这就是“cannot claim interface”错误消息的来源,因为设置精确配置时出现问题。如前所述,尝试
lsusb -v
或usb-devices
获取正确的信息…关于linux - libusb无法声明设备,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/44919347/