Get data from USB_ReadPacket function

[VCapu]

I am using a STM32F4 on a custom board with USB configured as custom hid device.

I need to know how to get the received data from the USB_ReadPacket placed inside the HAL_PCD_IRQHandler (I suppose this is the function called when the device receive data from USB).

This is the function:

/**

 * @brief USB_ReadPacket : read a packet from the RX FIFO

 * @param USBx Selected device

 * @param dest source pointer

 * @param len Number of bytes to read

 * @retval pointer to destination buffer

 */

void *USB_ReadPacket(USB_OTG_GlobalTypeDef *USBx, uint8_t *dest, uint16_t len)

{

 uint32_t USBx_BASE = (uint32_t)USBx;

 uint32_t *pDest = (uint32_t *)dest;

 uint32_t i;

 uint32_t count32b = ((uint32_t)len + 3U) / 4U;

 for (i = 0U; i < count32b; i++)

 {

  __UNALIGNED_UINT32_WRITE(pDest, USBx_DFIFO(0U));

  pDest++;

 }

 return ((void *)pDest);

}

Thank you

[VCapu]

Can anyone help me? Thanks

[Andrew Neil]

"how to get the received data from the USB_ReadPacket placed inside the HAL_PCD_IRQHandler"

Much the same way that you'd get data from any other interrupt handler?

Presumably, "destination" is the place for the data to go?

[VCapu]

I didn't manage to get data from the source. I get something that seems to be an address or isn't what I expect. Maybe I am not doing the right operations with the pointers. I should receive a buffer of data (len is equal to 8). Could you help me? Thank you

[VCapu]

It seems that I can receive the data through this function that is called by interrupt and adding the pointer read_buffer, that I use inside the RxUSB() function to get the data and do the necessary operations on it.

USBD_StatusTypeDef USBD_LL_PrepareReceive(USBD_HandleTypeDef *pdev, uint8_t ep_addr, uint8_t *pbuf, uint32_t size)

{

 HAL_StatusTypeDef hal_status = HAL_OK;

 USBD_StatusTypeDef usb_status = USBD_OK;

 read_buffer = pbuf;

 hal_status = HAL_PCD_EP_Receive(pdev->pData, ep_addr, pbuf, size);

 usb_status = USBD_Get_USB_Status(hal_status);

if(usb_status == USBD_OK) 

RxUSB(); 

 return usb_status;

}

Instead I transmit using in every point I need (for example in the functions that are in the Main) the function USBD_CUSTOM_HID_SendReport(&hUsbDeviceFS, ArrayTxUSB, CODA_USB);. It's not called by an interrupt.

But I am seeing that the communication stops to work soon and sometimes I can't even transmit. Maybe this is not the right way to trasmit and receive.

Could anyone help me? I'm stuck on this problem.