78 Linux libusb库USB HID应用编程笔记

本文主要是介绍78 Linux libusb库USB HID应用编程笔记，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

1 前言

这几天搞另外一个项目，基于Ubuntu开发一个小的应用程序，就是通过USB HID与设备通信。因此需要在Linux环境编写对应USB HID通信应用。

目前libusb库已经很好的支持USB相关应用的开发，库中提供了丰富的USB接口，用户可以直接调用其提供的API，实现快速开发。

本文对USB HID应用开发进行了简要记录，方便日后自己查看复习。

2 libusb库准备

（1）获取libusb库源码

下面链接是libusb库的源码下载地址。

libusb库源码：https://github.com/libusb/libusb/releases

（2）编译libusb库

获取到源码之后，需要对库进行编译，下面记录了自己编译的指令。

cd libusb-1.0.26/
#配置
./configure --prefix=/home/libusbinstall --build=x86_64-linux --disable-udev
#编译
make
#安装
make install

（3）安装目录

安装之后可以看到目标目录存在两个文件夹：include/ 和 lib/

3 应用示例

下面直接上代码，无需多言，看代码即可（代码风格及规范进行了简化，实际上没那么丑的）。

头文件：hidusb.h

#include <stdint.h>#include "libusb.h"int hidUSB_write(libusb_device_handle *dev_handle, unsigned char endpoint, unsigned char *pDataIn, int nDataLen, int ntimeout);
int hidUSB_read(libusb_device_handle *dev_handle,unsigned char endpoint, unsigned char *pDataRcv, int nDataLen, int ntimeout);
int hidUSB_open(libusb_device_handle **dev_hdlout, uint16_t vendor_id, uint16_t product_id);
int hidUSB_close(libusb_device_handle *dev_handle);void hidUSB_DeInit(void);
int hidUSB_Init(void);

源文件：hidusb.c

#include <stdio.h>
#include <stdint.h>
#include <string.h>#include "hidusb.h"static libusb_context 			*gUSBCtx = NULL;int hidUSB_write(libusb_device_handle *dev_handle, unsigned char endpoint, unsigned char *pDataIn, int nDataLen, int ntimeout)
{int ret = -1;int transferred = 0;ret = libusb_interrupt_transfer(dev_handle, endpoint, pDataIn, nDataLen, &transferred, ntimeout);if(ret<0){perror("failed to write\n");return 0;}return transferred;}int hidUSB_read(libusb_device_handle *dev_handle,unsigned char endpoint, unsigned char *pDataRcv, int nDataLen, int ntimeout)
{int ret = -1;int transferred = 0;ret = libusb_interrupt_transfer(dev_handle,endpoint, pDataRcv, 64, &transferred, ntimeout);if(ret!=0){perror("failed to read\n");return 0;}return transferred;}int hidUSB_open(libusb_device_handle **dev_hdlout, uint16_t vendor_id, uint16_t product_id)
{int ret = -1;libusb_device_handle *tdev_handle = NULL;//打开指定pid和vid的设备tdev_handle = libusb_open_device_with_vid_pid(NULL, vendor_id, product_id);if(tdev_handle == NULL){perror("Cannot open device\n");return -1;}//内核驱动激活与分离（这一句我没怎么搞懂为啥需要，懂的朋友欢迎留言告诉我）if(libusb_kernel_driver_active(tdev_handle, 0) == 1){ printf("Kernel Driver Active\n");if(libusb_detach_kernel_driver(tdev_handle, 0) == 0){printf("Kernel Driver Detached!\n");}}ret = libusb_claim_interface(tdev_handle, 0);if(ret < 0) {perror("Cannot Claim Interface\n");goto iExit;}*dev_hdlout = tdev_handle;return 0;iExit:	if(tdev_handle)libusb_close(tdev_handle);return -1;
}int hidUSB_close(libusb_device_handle *dev_handle)
{int ret = -1;if(dev_handle){ret = libusb_release_interface(dev_handle, 0);if(ret!=0){	perror("Cannot libusb_release_interface\n");return -1;}libusb_close(dev_handle);}return 0;
}void hidUSB_DeInit(void)
{libusb_exit(gUSBCtx);
}int hidUSB_Init(void)
{int ret = -1;ret = libusb_init(&gUSBCtx); if(ret < 0) {perror("libusb_init failed\n");return -1;	} return 0;
}

主程序：main.c

#include <stdio.h>
#include <unistd.h>
#include "hidusb.h"//设备的标识号
#define HT232_USB_VID 			0x5548
#define HT232_USB_PID 			0x6666//这个需要看设备所使用的ep
#define HT232_USB_HID_EPOUT		0x01
#define HT232_USB_HID_EPIN		0x81int main(void)
{int ni = 0;int nRet = -1;uint8_t ucSndBuf[256] = {0};uint8_t ucRcvBuf[256] = {0};uint8_t ucSndLen = 0;uint8_t ucRcvLen = 0;libusb_device_handle *dev_handle = NULL;nRet =  hidUSB_Init();if(nRet != 0){perror("hidUSB_Init failed\r\n");return -1;}nRet = hidUSB_open(&dev_handle, HT232_USB_VID, HT232_USB_PID);if(nRet != 0){perror("hidUSB_open failed\r\n");return -1;}while(1){ucSndBuf[0] = 0x01;ucSndBuf[1] = 0x02;ucSndBuf[2] = 0x03;ucSndBuf[3] = 0x04;ucSndLen = 4;nRet =  hidUSB_write(dev_handle, HT232_USB_HID_EPOUT, ucSndBuf, ucSndLen, 1000);if(nRet == 0){perror("hidUSB_write failed\r\n");goto iSleep;}ucRcvLen =  hidUSB_read(dev_handle, HT232_USB_HID_EPIN, ucRcvBuf, sizeof(ucRcvBuf), 1000);if(ucRcvLen == 0){perror("hidUSB_read failed\r\n");goto iSleep;}for(ni=0; ni<ucRcvLen; ni++){printf("%02X ", ucRcvBuf[ni]);}printf("\r\n");
iSleep:sleep(1);}nRet = hidUSB_close(dev_handle);if(nRet != 0){perror("hidUSB_open failed\r\n");}hidUSB_DeInit();return 0;
}

上述即为Linux环境下USB HID应用编程demo。