前段時間公司開發了一個安卓外設，主要是用某寶淘來的demo 在stm32F103的usb功能來和安卓設備的usb來通訊

敘述之前先來一個整體的框圖吧：

需要準備的設備有：

①.安卓手機或者安卓pad，（手機必須支持otg功能，否則就得用host功能了）

②.otg轉接線或者轉接頭

③.安卓數據線（一定要是能通訊數據的線纜，有些山寨的這個線只有2根線，沒有數據線）

④.帶有usb功能的單片機（這個usb需要能支持用戶自行定義）

接下來就開始搗鼓stm32單片機的程序了，下面是usb功能的代碼：

usb功能看了一下主要是借助hid的標準協議上衍生而來的一個usb標準設備

/******************** (C) COPYRIGHT 2010 STMicroelectronics ********************

* File Name          : usb_desc.c

* Author             : MCD Application Team

* Version            : V3.2.1

* Date               : 07/05/2010

* Description        : Descriptors for Mass Storage Device

********************************************************************************

* THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS

* WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE TIME.

* AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY DIRECT,

* INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING FROM THE

* CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE CODING

* INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.

*******************************************************************************/

/* Includes ------------------------------------------------------------------*/

#include "usb_desc.h"

/* Private typedef -----------------------------------------------------------*/

/* Private define ------------------------------------------------------------*/

/* Private macro -------------------------------------------------------------*/

/* Private variables ---------------------------------------------------------*/

/* Extern variables ----------------------------------------------------------*/

/* Private function prototypes -----------------------------------------------*/

/* Private functions ---------------------------------------------------------*/

/* USB Standard Device Descriptor */

const u8 CustomHID_DeviceDescriptor[CUSTOMHID_SIZ_DEVICE_DESC] =

  {

    0x12,                       /*bLength */

    USB_DEVICE_DESCRIPTOR_TYPE, /*bDescriptorType*/

    0x00,0x02,                  /*bcdUSB */

    0x00,                       /*bDeviceClass*/

    0x00,                       /*bDeviceSubClass*/

    0x00,                       /*bDeviceProtocol*/

    0x08,                       /*bMaxPacketSize40*/

    0x71,0x04,                  /*idVendor (0x0471)*/

    0x08,0x24,                  /*idProduct = 0x2408*/

    0x00,0x02,                  /*bcdDevice rel. 2.00*/

    1,                          /*Index of string descriptor describing manufacturer */

    2,                          /*Index of string descriptor describing product*/

    3,                          /*Index of string descriptor describing the device serial number */

    0x01                        /*bNumConfigurations*/

  }

  ; /* CustomHID_DeviceDescriptor */

/* USB Configuration Descriptor */

/*   All Descriptors (Configuration, Interface, Endpoint, Class, Vendor */

const u8 CustomHID_ConfigDescriptor[ENEPOINT_NUM*7+18] =

  {

    0x09, /* bLength: Configuation Descriptor size */

    USB_CONFIGURATION_DESCRIPTOR_TYPE, /* bDescriptorType: Configuration */

    ENEPOINT_NUM*7+18,    /*CUSTOMHID_SIZ_CONFIG_DESC, wTotalLength: Bytes returned */

    0x00,

    0x01,         /* bNumInterfaces: 1 interface */

    0x01,         /* bConfigurationValue: Configuration value */

    0x00,         /* iConfiguration: Index of string descriptor describing

                                 the configuration*/

    0xC0,         /* bmAttributes: Bus powered */

    0x32,         /* MaxPower 100 mA: this current is used for detecting Vbus */

    /************** Descriptor of Custom HID interface ****************/

    /* 09 */

    0x09,         /* bLength: Interface Descriptor size */

    USB_INTERFACE_DESCRIPTOR_TYPE,/* bDescriptorType: Interface descriptor type */

    0x00,         /* bInterfaceNumber: Number of Interface */

    0x00,         /* bAlternateSetting: Alternate setting */

    ENEPOINT_NUM,         /* bNumEndpoints */

    0x00,         /* bInterfaceClass: HID=0X03,其他選0 */

    0x00,         /* bInterfaceSubClass : 1=BOOT, 0=no boot */

    0x00,         /* nInterfaceProtocol : 0=none, 1=keyboard, 2=mouse */

    0,            /* iInterface: Index of string descriptor */

    /********************以下只對HID的描述符  Descriptor of Custom HID HID ********************/

    /* 18 */

  //  0x09,         /* bLength: HID Descriptor size */

  //  HID_DESCRIPTOR_TYPE, /* bDescriptorType: HID */

  //  0x10,         /* bcdHID: HID Class Spec release number */

  //  0x01,

  //  0x00,         /* bCountryCode: Hardware target country */

  //  0x01,         /* bNumDescriptors: Number of HID class descriptors to follow */

  //  0x22,         /* bDescriptorType */

  //  CUSTOMHID_SIZ_REPORT_DESC,/* wItemLength: Total length of Report descriptor */

  //  0x00,

  /******************** Descriptor of Custom endpoints ******************/

    0x07, /* bLength: Endpoint Descriptor size */

    USB_ENDPOINT_DESCRIPTOR_TYPE, /* bDescriptorType: */

/* Endpoint descriptor type */

    0x01, /* bEndpointAddress: */

/* Endpoint Address (OUT) */

    USB_ENDPOINT_TYPE_BULK,/* bmAttributes: Interrupt endpoint */

    0x10,0x00, /* wMaxPacketSize: 32 Bytes max  */

    0x20, /* bInterval: Polling Interval (20 ms) */

   /* 27 */  

    0x07,          /* bLength: Endpoint Descriptor size */

    USB_ENDPOINT_DESCRIPTOR_TYPE, /* bDescriptorType: */

    0x81,          /* bEndpointAddress: Endpoint Address (IN) */

  USB_ENDPOINT_TYPE_BULK,          /* bmAttributes: Interrupt endpoint */

    0x10, 0x00,         /* wMaxPacketSize: 32 Bytes max */

    0x20,          /* bInterval: Polling Interval (32 ms) */

    /* 34 */

    0x07, /* bLength: Endpoint Descriptor size */

    USB_ENDPOINT_DESCRIPTOR_TYPE, /* bDescriptorType: */

/* Endpoint descriptor type */

    0x82, /* bEndpointAddress: */

/* Endpoint Address (OUT) */

    USB_ENDPOINT_TYPE_BULK,/* bmAttributes: Interrupt endpoint */

    0x40,0x00, /* wMaxPacketSize: 512 Bytes max  */

    0x20 /* bInterval: Polling Interval (20 ms) */   

  }

  ;

/* USB String Descriptors (optional) */

const u8 CustomHID_StringLangID[CUSTOMHID_SIZ_STRING_LANGID] =

  {

CUSTOMHID_SIZ_STRING_LANGID,

USB_STRING_DESCRIPTOR_TYPE,

0x09,

0x04

  }

  ; /* LangID = 0x0409: U.S. English */

const u8 CustomHID_StringVendor[CUSTOMHID_SIZ_STRING_VENDOR] =

  {

    CUSTOMHID_SIZ_STRING_VENDOR, /* Size of Vendor string */

    USB_STRING_DESCRIPTOR_TYPE,  /* bDescriptorType*/

    /* Manufacturer: "STMicroelectronics" */

'O', 0,

'T', 0,

'G', 0,

  };

const u8 CustomHID_StringProduct[CUSTOMHID_SIZ_STRING_PRODUCT] =

  {

    CUSTOMHID_SIZ_STRING_PRODUCT,          /* bLength */

    USB_STRING_DESCRIPTOR_TYPE,        /* bDescriptorType */

'S', 0,

'T', 0,

'M', 0,

'3', 0,

'2', 0,

'A',0,

'n',0,

'd',0,

'r',0,

'o',0,

'i',0,

'd',0,

' ',0,

'U',0,

'S',0,

'B',0,

' ',0,

'O', 0,

'T', 0,

'G', 0,

  };

u8 CustomHID_StringSerial[CUSTOMHID_SIZ_STRING_SERIAL] =

  {

    CUSTOMHID_SIZ_STRING_SERIAL,           /* bLength */

    USB_STRING_DESCRIPTOR_TYPE,        /* bDescriptorType */

'T', 0,

'a', 0,

'o', 0,

'b', 0,

'a', 0,

'o', 0,

'-', 0,

'B', 0,

'e', 0,

'i', 0,

'j', 0,

'i',0,

'n',0,

'g',0,

'Y',0,