STM32_USB_HAL - GitMasterNikanjam/ARM_WiKi GitHub Wiki

Configuration in STM32CUBEMX

1- Go to Connectivity- -> USB_OTG_FS
2- Select mode to Device only
3- Go to Middleware and Software Packs -> USB_DEVICE
4- Select Class For FS IP to Communication Device Class (Virtual Port Com)

Program Code in IDE

Important Functions

• static int8_t CDC_Receive_FS(uint8_t* Buf, uint32_t *Len);
• uint8_t CDC_Transmit_FS(uint8_t* Buf, uint16_t Len);

Steps in Code

1- Add #include "usbd_cdc_if.h" at USER CODE Includes in main.c file
2- Add uint8_t buffer[64]; at USER CODE Global Private variables in main.c file
buffer[64] is a variable that store data at receive usb data. the size and name of it can be arbitrary.
3- Add extern uint8_t buffer[64]; at USER CODE Global Private variables in usbd_cdc_if.c file
4- Edit CDC_Receive_FS function in usbd_cdc_if.c file:

static int8_t CDC_Receive_FS(uint8_t* Buf, uint32_t *Len)
{
  /* USER CODE BEGIN 6 */
  USBD_CDC_SetRxBuffer(&hUsbDeviceFS, &Buf[0]);
  USBD_CDC_ReceivePacket(&hUsbDeviceFS);
	uint8_t len = (uint8_t) *Len;
	memset(buffer, '\0', 64);
	memcpy(buffer, Buf,len);
	memset(Buf, '\0', len);
  return (USBD_OK);
  /* USER CODE END 6 */
}

5- Use CDC_Transmit_FS(uint8_t* Buf, uint16_t Len) function in main.c file