源：Qt下libusb-win32的使用(一)打印设备描述符
主要是在前一篇的基础上，学习libusb-win32的API使用。程序很简单，就是打印指定USB设备的设备描述符(当然其他描述符也是可以的)。
#include "testlibusb.h" #define MY_VID 0x5345 #define MY_PID 0x1234 USB::USB() { usb_init(); /* initialize the library */ //usb_set_debug(255); usb_find_busses(); /* find all busses */ usb_find_devices(); /* find all connected devices */ if (!(udev = open_dev())) { qDebug("error opening device: %s", usb_strerror()); exit(1); } else qDebug("open success: device %04X:%04X opened", MY_VID, MY_PID); printf_device_descriptor(&dev->descriptor); usb_close(udev); //my_usb_get_device_list(); resize(320, 240); } usb_dev_handle *USB::open_dev(void) { struct usb_bus *bus; //struct usb_device *dev; for(bus = usb_get_busses(); bus; bus = bus->next) { for(dev = bus->devices; dev; dev = dev->next) { if((dev->descriptor.idVendor == MY_VID) && (dev->descriptor.idProduct == MY_PID)) { return usb_open(dev); } } } return 0; } void USB::printf_device_descriptor(usb_device_descriptor *desc) { qDebug("bLength: %u", desc->bLength); qDebug("bDescriptorType: %02Xh", desc->bDescriptorType); qDebug("bcdUSB: %04Xh", desc->bcdUSB); qDebug("bDeviceClass: %02Xh", desc->bDeviceClass); qDebug("bDeviceSubClass: %02Xh", desc->bDeviceSubClass); qDebug("bDeviceProtocol: %02Xh", desc->bDeviceProtocol); qDebug("bMaxPacketSize0: %02Xh", desc->bMaxPacketSize0); qDebug("idVendor: %04Xh", desc->idVendor); qDebug("idProduct: %04Xh", desc->idProduct); qDebug("bcdDevice: %04Xh", desc->bcdDevice); qDebug("iManufacturer: %u", desc->iManufacturer); qDebug("iProduct: %u", desc->iProduct); qDebug("iSerialNumber: %u", desc->iSerialNumber); qDebug("bNumConfigurations: %u", desc->bNumConfigurations); }
这里我指定的USB设备是Tiny6410开发板。运行效果如下：
下一步就是上位机与开发板进行数据互传。
一、概述
学习libusb-win32的使用。使用批量传输方式与USB开发板进行数据读、写操作。上位机使用Qt做界面， 使用USB开发板的端点2作为批量传输端点。
二、实现
代码比较简单，直接给出，如下：
#include "testlibusb.h" //for Tiny6410 //#define MY_VID 0x5345 //#define MY_PID 0x1234 //for 51 USB Board #define MY_VID 0x8888 #define MY_PID 0x0001 // Device configuration and interface id. #define MY_CONFIG 1 #define MY_INTF 0 // Device endpoint 2 #define EP_IN 0x82 #define EP_OUT 0x02 // Device of bytes to transfer. #define BUF_SIZE 64 //#define DEBUG_GUI USB::USB() { #ifndef DEBUG_GUI usb_init(); /* initialize the library */ //usb_set_debug(255); usb_find_busses(); /* find all busses */ usb_find_devices(); /* find all connected devices */ if (!(udev = open_dev())) { qDebug("error opening device: %s", usb_strerror()); exit(1); } else qDebug("open success: device %04X:%04X opened", MY_VID, MY_PID); printf_device_descriptor(&dev->descriptor); my_init_usbdev(); #endif textEdit = new QTextEdit(this); textEdit->setGeometry(50,20,230,40); sendButton = new QPushButton(this); sendButton->setText("send"); sendButton->setGeometry(130,80,60,40); connect(sendButton,SIGNAL(clicked()),this,SLOT(send_slot())); readButton = new QPushButton(this); readButton->setText("read"); readButton->setGeometry(130,140,60,40); connect(readButton,SIGNAL(clicked()),this,SLOT(read_slot())); recvLabel = new QLabel(this); recvLabel->setText("recv data:"); recvLabel->setGeometry(20,180,280,40); //my_usb_get_device_list(); resize(320, 240); } //关闭程序时被调用 USB::~USB() { #ifndef DEBUG_GUI qDebug("close usb device."); usb_close(udev); #endif } //打开指定VID、PID的USB设备 usb_dev_handle *USB::open_dev(void) { struct usb_bus *bus; for(bus = usb_get_busses(); bus; bus = bus->next) { for(dev = bus->devices; dev; dev = dev->next) { if((dev->descriptor.idVendor == MY_VID) && (dev->descriptor.idProduct == MY_PID)) { return usb_open(dev); } } } return 0; } //打印USB设备描述符 void USB::printf_device_descriptor(usb_device_descriptor *desc) { qDebug("bLength: %u", desc->bLength); qDebug("bDescriptorType: %02Xh", desc->bDescriptorType); qDebug("bcdUSB: %04Xh", desc->bcdUSB); qDebug("bDeviceClass: %02Xh", desc->bDeviceClass); qDebug("bDeviceSubClass: %02Xh", desc->bDeviceSubClass); qDebug("bDeviceProtocol: %02Xh", desc->bDeviceProtocol); qDebug("bMaxPacketSize0: %02Xh", desc->bMaxPacketSize0); qDebug("idVendor: %04Xh", desc->idVendor); qDebug("idProduct: %04Xh", desc->idProduct); qDebug("bcdDevice: %04Xh", desc->bcdDevice); qDebug("iManufacturer: %u", desc->iManufacturer); qDebug("iProduct: %u", desc->iProduct); qDebug("iSerialNumber: %u", desc->iSerialNumber); qDebug("bNumConfigurations: %u", desc->bNumConfigurations); } //指定USB设备的配置和接口 void USB::my_init_usbdev() { //libusb规定下面这两个函数必须要被调用 if (usb_set_configuration(udev, MY_CONFIG) < 0) { qDebug("error setting config #%d: %s", MY_CONFIG, usb_strerror()); exit(1); } if (usb_claim_interface(udev, MY_INTF) < 0) { qDebug("error claiming interface #%d: %s", MY_INTF, usb_strerror()); exit(1); } } //发送按钮响应函数 void USB::send_slot() { int ret, num; QString s = textEdit->toPlainText(); QByteArray a = s.toLatin1(); char *tmp = a.data(); num = s.length(); //qDebug()<<"text: "<<tmp<<"length: "<<num; //批量写(同步) ret = usb_bulk_write(udev, EP_OUT, tmp, num, 5000); if (ret < 0) { qDebug("error writing: %s", usb_strerror()); exit(1); } } //读按钮响应函数 void USB::read_slot() { int ret; char readdata[BUF_SIZE]; //批量读(同步) ret = usb_bulk_read(udev, EP_IN, readdata, sizeof(readdata), 5000); if (ret < 0) { qDebug("error reading:%s", usb_strerror()); exit(1); } readdata[ret] = ' '; //将接收到的数据显示在Label上 recvLabel->setText("recv: " + QLatin1String(readdata)); }
三、结果
运行上位机程序，在编辑框输入一些字符(数字)，然后点击“send”按钮将数据发送给USB设备，点击“read”按钮将USB设备接收到的数据读回到上位机并显示在界面上，效果如下：
