STM32H750-DK FD CAN packet reception is not working in normal mode

[Kasun Dinesh]

HI all,

I am developing a CAN FD application using STM32H750-DK. Packet reception to FIFO is working in External Loopback mode and packet transmission works as well. But once I change the mode to Normal, packet reception (FIFO interrupt) dosent fire If i send a packet to the DK and (receiving does not work). It seems its not ack the receiving packets. This is the code I m using.

static void MX_FDCAN1_Init(void)
{
 
  /* USER CODE BEGIN FDCAN1_Init 0 */
 
  /* USER CODE END FDCAN1_Init 0 */
 
  /* USER CODE BEGIN FDCAN1_Init 1 */
 
  /* USER CODE END FDCAN1_Init 1 */
  hfdcan1.Instance = FDCAN1;
  hfdcan1.Init.FrameFormat = FDCAN_FRAME_FD_BRS;
  hfdcan1.Init.Mode = FDCAN_MODE_NORMAL;
  hfdcan1.Init.AutoRetransmission = DISABLE;
  hfdcan1.Init.TransmitPause = DISABLE;
  hfdcan1.Init.ProtocolException = DISABLE;
  hfdcan1.Init.NominalPrescaler = 1;
  hfdcan1.Init.NominalSyncJumpWidth = 8;
  hfdcan1.Init.NominalTimeSeg1 = 0x1f;
  hfdcan1.Init.NominalTimeSeg2 = 8;
  hfdcan1.Init.DataPrescaler = 1;
  hfdcan1.Init.DataSyncJumpWidth = 8;
  hfdcan1.Init.DataTimeSeg1 = 0x1f;
  hfdcan1.Init.DataTimeSeg2 = 8;
  hfdcan1.Init.MessageRAMOffset = 0;
  hfdcan1.Init.StdFiltersNbr = 0;
  hfdcan1.Init.ExtFiltersNbr = 1;
  hfdcan1.Init.RxFifo0ElmtsNbr = 1;
  hfdcan1.Init.RxFifo0ElmtSize = FDCAN_DATA_BYTES_64;
  hfdcan1.Init.RxFifo1ElmtsNbr = 0;
  hfdcan1.Init.RxFifo1ElmtSize = FDCAN_DATA_BYTES_64;
  hfdcan1.Init.RxBuffersNbr = 0;
  hfdcan1.Init.RxBufferSize = FDCAN_DATA_BYTES_64;
  hfdcan1.Init.TxEventsNbr = 0;
  hfdcan1.Init.TxBuffersNbr = 0;
  hfdcan1.Init.TxFifoQueueElmtsNbr = 1;
  hfdcan1.Init.TxFifoQueueMode = FDCAN_TX_FIFO_OPERATION;
  hfdcan1.Init.TxElmtSize = FDCAN_DATA_BYTES_12;
  if (HAL_FDCAN_Init(&hfdcan1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN FDCAN1_Init 2 */
 
	/* Configure extended ID reception filter to Rx FIFO 1 */
	sFilterConfig.IdType = FDCAN_EXTENDED_ID;
	sFilterConfig.FilterIndex = 0;
	sFilterConfig.FilterType = FDCAN_FILTER_MASK;
	sFilterConfig.FilterConfig = FDCAN_FILTER_TO_RXFIFO0;
	sFilterConfig.FilterID1 = 0x2011FFF;
	sFilterConfig.FilterID2 = 0xFFFFFFF;
	if (HAL_FDCAN_ConfigFilter(&hfdcan1, &sFilterConfig) != HAL_OK)
	{
		Error_Handler();
	}
 
	if (HAL_FDCAN_DisableEdgeFiltering(&hfdcan1) != HAL_OK)
	{
		Error_Handler();
	}
 
 
	if (HAL_FDCAN_ConfigInterruptLines(&hfdcan1, 0xFFFFFFFF, FDCAN_INTERRUPT_LINE0) != HAL_OK)
	{
		  Error_Handler();
	}
 
	if(HAL_FDCAN_ActivateNotification(&hfdcan1,FDCAN_IT_RX_FIFO0_NEW_MESSAGE,0) != HAL_OK)
	{
	  Error_Handler();
	}
 
	if(HAL_FDCAN_ConfigGlobalFilter(&hfdcan1, FDCAN_ACCEPT_IN_RX_FIFO0, FDCAN_ACCEPT_IN_RX_FIFO0, FDCAN_FILTER_REMOTE, FDCAN_FILTER_REMOTE) != HAL_OK)
	{
		Error_Handler();
	}
 
	if (HAL_FDCAN_Start(&hfdcan1) != HAL_OK)
	{
	  Error_Handler();
	}
 
    /* Add second message to Tx FIFO */
    TxHeader.Identifier = 0x2011FFF;
    TxHeader.IdType = FDCAN_EXTENDED_ID;
    TxHeader.TxFrameType = FDCAN_DATA_FRAME;
    TxHeader.DataLength = FDCAN_DLC_BYTES_12;
    TxHeader.ErrorStateIndicator = FDCAN_ESI_PASSIVE;
    TxHeader.BitRateSwitch = FDCAN_BRS_OFF;
    TxHeader.FDFormat = FDCAN_FD_CAN;
    TxHeader.TxEventFifoControl = FDCAN_STORE_TX_EVENTS;
    TxHeader.MessageMarker = 0xDD;
 
    while(1)
    {
		if(HAL_FDCAN_AddMessageToTxFifoQ(&hfdcan1, &TxHeader, TxData2) != HAL_OK)
		{
		  Error_Handler();
		}
		HAL_Delay(1000);
    }
 
  /* USER CODE END FDCAN1_Init 2 */
 
}
 
 
void HAL_FDCAN_RxFifo0Callback(FDCAN_HandleTypeDef *hfdcan, uint32_t RxFifo0ITs)
{
	FDCAN_RxHeaderTypeDef   RxHeader;
 
	if((RxFifo0ITs & FDCAN_IT_RX_FIFO0_NEW_MESSAGE) != RESET)
	{
		/* Retrieve Rx messages from RX FIFO0 */
		if (HAL_FDCAN_GetRxMessage(hfdcan, FDCAN_RX_FIFO0, &RxHeader, RxData) != HAL_OK)
		{
		Error_Handler();
		}
 
		/* Display LEDx */
		if ((RxHeader.Identifier == 0x321) && (RxHeader.IdType == FDCAN_STANDARD_ID) && (RxHeader.DataLength == FDCAN_DLC_BYTES_2))
		{
		  //LED_Display(RxData[0]);
		  //ubKeyNumber = RxData[0];
		}
	}
 
	if(HAL_FDCAN_ActivateNotification(&hfdcan1,FDCAN_IT_RX_FIFO0_NEW_MESSAGE,0) != HAL_OK)
	{
	  Error_Handler();
	}
}

Can some one help me to figure out the issue. Thanks

[Tesla DeLorean]

Do you have two units communicating with each other?

What if you accept all packets, which do you see then?

The Extended ID is 29-bits as I recall, not 28

Unlikely to see any Standard ID packets in the callback if you're not filtering for them.

[Kasun Dinesh]

HI Clive,

Thanks for your reply.

Do you have two units communicating with each other?

• Yes. The 2nd device i used has a working CAN interface. It receives the packets I am sending via STM32F750-DK

What if you accept all packets, which do you see then?

• I tried that by setting sFilterConfig.FilterID2 = 0x0000000; I can see it execute HAL_FDCAN_RxFifo0Callback in external loopback or loopback mode. But I dont get that event in normal mode. What i saw is STM does not acknowledge the receiving packet. Because the other device continually transmit the same packet.

Any idea why its not acknowledging?