如何在Linux下利用Libusb与HID USB设备通信

由于公司的产品，导致我在Linux下写usb通信的代码出现了许多的问题，最后发现这些设备只能通过控制传输来 *** 作设备，所以后面的问题就迎刃而解了。现在贴上当时在QT下写的代码，以防日后再碰到此类问题的时升源候型雀翻查。

还有在QT下使用libusb库的时候一定要在（项目名吵租态.pro）文件加上：

[cpp] view plain copy

INCLUDEPATH += /usr/include/libusb-1.0

LIBS += -L"/usr/lib/x86_64-linux-gnu" -lusb-1.0

否则程序无法找到该库的路径。

[cpp] view plain copy

libusb_device **devs

libusb_device_handle *dev_handle

libusb_context *ctx=NULL

struct libusb_device_descriptor desc

int r

ssize_t cnt

r=libusb_init(&ctx)

if(r<0)

{

//printf("init error")

QMessageBox::about(this,"haha","initialerror")

return

}

libusb_set_debug(ctx,3)

//cnt=libusb_get_device_list(ctx,&devs)

dev_handle=libusb_open_device_with_vid_pid(ctx,VID,PID)

if(dev_handle==NULL)

QMessageBox::about(this,"haha","open my dev error")

else

QMessageBox::about(this,"haha","open my dev success")

//libusb_free_device_list(devs,1)

if(libusb_kernel_driver_active(dev_handle,0)==1)

{

QMessageBox::about(this,"haha","kernel driver active")

if(libusb_detach_kernel_driver(dev_handle,0)==0)

QMessageBox::about(this,"haha","kernel driver detached")

}

r=libusb_claim_interface(dev_handle,0)

if(r<0)

{

QMessageBox::about(this,"haha","cannot claim interface")

return

}

QMessageBox::about(this,"haha","claimed interface")

// start use this usb

unsigned char dataOut[0x30]={0}

dataOut[0]=0x00

dataOut[1]=0x02

dataOut[2]=0x08

dataOut[3]=0x00

dataOut[4]=0x02

dataOut[5]=0x00

dataOut[6]=0xb2

dataOut[7]=0x30

dataOut[8]=dataOut[2]^dataOut[3]^dataOut[4]^dataOut[5]^dataOut[6]^dataOut[7]

//r=libusb_interrupt_transfer(dev_handle,LIBUSB_ENDPOINT_OUT, dataOut,9, &actual_length, 0)

//r=libusb_bulk_transfer(dev_handle,LIBUSB_ENDPOINT_OUT,dataOut,9,&actual_length,5000)

//此设备必须用控制传输

r=libusb_control_transfer(dev_handle, 0x21, 0x09, 0x0300, 0x00, dataOut+1, 0x20, 1000)

unsigned char dataRead[0x30]={0}

r=libusb_control_transfer(dev_handle, 0xa1, 0x01, 0x0300, 0x00, dataRead, 0x20, 1000)

if(r<0)

{

QMessageBox::about(this,"haha","transfer data error")

}else

{

QMessageBox::about(this,"haha","transfer data success")

}

//release everything

r=libusb_release_interface(dev_handle,0)

libusb_attach_kernel_driver(dev_handle,0)

libusb_close(dev_handle)

libusb_exit(ctx)

首先需要了解Linux输入子系统，因为鼠标是输入设备，一种input_device。然后需伏高要了解USB设备驱动。使用了USB接橡段口，urb来获得鼠标的数据，然后把数据往上层应用提交。可以参看内核已经有的USB鼠标驱动，位置是\linux-3.0.86\drivers\hid\usbhid\usbmouse.c。linux-3.0.86是Linux内核的根目录。并不难。至于哪些书，可以看‘Linux设备驱动程序’这缺如尺本书，里头主要知识都有讲到。

---