基于stm32f130 固件库 给出usb虚拟串口通信

好的，下面是基于 STM32F1xx 标准外设库实现 USB 虚拟串口通信的代码：

#include "stm32f1xx.h"
#include "usbd_cdc_if.h"

#define APP_RX_DATA_SIZE  2048
#define APP_TX_DATA_SIZE  2048

uint8_t UserRxBufferFS[APP_RX_DATA_SIZE];
uint8_t UserTxBufferFS[APP_TX_DATA_SIZE];

USBD_CDC_LineCodingTypeDef LineCoding = {
  115200, /* baud rate*/
  0x00,   /* stop bits-1*/
  0x00,   /* parity - none*/
  0x08    /* nb. of bits 8*/
};

USBD_HandleTypeDef hUsbDeviceFS;

static void MX_USB_DEVICE_Init(void)
{
  hUsbDeviceFS.Instance = USB;
  hUsbDeviceFS.Init.dev_endpoints = 7;
  hUsbDeviceFS.Init.speed = USBD_SPEED_FULL;
  hUsbDeviceFS.Init.ep0_mps = DEP0CTL_MPS_64;
  hUsbDeviceFS.Init.dma_enable = DISABLE;
  hUsbDeviceFS.Init.low_power_enable = DISABLE;
  hUsbDeviceFS.Init.lpm_enable = DISABLE;
  hUsbDeviceFS.Init.battery_charging_enable = DISABLE;
  if (HAL_PCD_Init(&hUsbDeviceFS.pcd) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_PCDEx_SetRxFiFo(&hUsbDeviceFS.pcd, 0x80) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_PCDEx_SetTxFiFo(&hUsbDeviceFS.pcd, 0, 0x40) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_PCDEx_SetTxFiFo(&hUsbDeviceFS.pcd, 1, 0x80) != HAL_OK)
  {
    Error_Handler();
  }
}

void USB_Init(void)
{
  MX_USB_DEVICE_Init();
  USBD_Init(&hUsbDeviceFS, &CDC_Desc, DEVICE_FS);
  USBD_RegisterClass(&hUsbDeviceFS, &USBD_CDC);
  USBD_CDC_RegisterInterface(&hUsbDeviceFS, &USBD_Interface_fops_FS);
  USBD_Start(&hUsbDeviceFS);
}

void CDC_Transmit_FS(uint8_t* Buf, uint16_t Len)
{
  uint8_t result = USBD_OK;

  USBD_CDC_HandleTypeDef *hcdc = (USBD_CDC_HandleTypeDef*)hUsbDeviceFS.pClassData;
  if (hcdc->TxState != 0)
  {
    return;
  }
  USBD_CDC_SetTxBuffer(&hUsbDeviceFS, Buf, Len);
  result = USBD_CDC_TransmitPacket(&hUsbDeviceFS);
  if (result != USBD_OK)
  {
    Error_Handler();
  }
}

void HAL_PCD_MspInit(PCD_HandleTypeDef* pcdHandle)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};
  if(pcdHandle->Instance==USB)
  {
    /* USB clock enable */
    __HAL_RCC_USB_CLK_ENABLE();

    __HAL_RCC_GPIOA_CLK_ENABLE();
    /**USB GPIO Configuration    
    PA11     ------> USB_DM
    PA12     ------> USB_DP 
    */
    GPIO_InitStruct.Pin = GPIO_PIN_11|GPIO_PIN_12;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF14_USB;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    /* USB interrupt Init */
    HAL_NVIC_SetPriority(USB_LP_CAN1_RX0_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(USB_LP_CAN1_RX0_IRQn);
  }
}

void USB_LP_CAN1_RX0_IRQHandler(void)
{
  HAL_PCD_IRQHandler(&hUsbDeviceFS.pcd);
}

void Error_Handler(void)
{
  while (1)
  {
  }
}

以上代码中，`UserRxBufferFS` 和 `UserTxBufferFS` 分别是接收和发送缓冲区，`LineCoding` 是串口参数设置结构体，`USB_Init()` 函数用于初始化 USB 设备，`CDC_Transmit_FS()` 函数用于发送数据，`HAL_PCD_MspInit()` 函数用于初始化 USB 外设引脚，`USB_LP_CAN1_RX0_IRQHandler()` 函数是 USB 中断处理函数。

在使用此代码前，需要在 STM32CubeMX 中配置 USB 外设为 Virtual Com Port，然后生成代码即可。