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CAN bus AutoRetransmission Not working + Documentation Mismatch

EZamo.1
Associate III

Using a Nucleo-H743 board, which unfortunately does not have a FD/CAN example

( https://github.com/STMicroelectronics/STM32CubeH7/tree/master/Projects/NUCLEO-H743ZI/Examples )

But following the code for similar chips, I do see an output on PD1. However it's only ONCE... with nothing attached to the bus, I'd expect retries. Also, if I add another message to the FIFO, it does not send it. The only way to get one output again, is to re-initialize the peripheral.

hfdcan1.Instance = FDCAN1;
	hfdcan1.Init.FrameFormat = FDCAN_FRAME_CLASSIC; // FDCAN_FRAME_FD_BRS;
	hfdcan1.Init.Mode = FDCAN_MODE_NORMAL;
	hfdcan1.Init.AutoRetransmission = ENABLE;  //**************************
	hfdcan1.Init.TransmitPause = DISABLE;
	hfdcan1.Init.ProtocolException = ENABLE;
	hfdcan1.Init.NominalPrescaler = 0x1; /* tq = NominalPrescaler x (1/fdcan_ker_ck) */
	hfdcan1.Init.NominalSyncJumpWidth = 0x10;
	hfdcan1.Init.NominalTimeSeg1 = 0x3F; 
	hfdcan1.Init.NominalTimeSeg2 = 0x10;
	hfdcan1.Init.DataPrescaler = 0x1;
	hfdcan1.Init.DataSyncJumpWidth = 0x4;
	hfdcan1.Init.DataTimeSeg1 = 0xF; 
	hfdcan1.Init.DataTimeSeg2 = 0x4;
	hfdcan1.Init.StdFiltersNbr = 1;  
	hfdcan1.Init.ExtFiltersNbr = 0;
	hfdcan1.Init.RxFifo1ElmtsNbr = 0;
	hfdcan1.Init.TxEventsNbr = 0;
 
	HAL_FDCAN_Init(&hfdcan1);
 
	/* Start the FDCAN module */
	if (HAL_FDCAN_Start(&hfdcan1) != HAL_OK)
	{
		/* Start Error */
		Error_Handler();
	}
 
	if (HAL_FDCAN_ActivateNotification(&hfdcan1, FDCAN_IT_RX_FIFO0_NEW_MESSAGE, 0) != HAL_OK)  // Enable Rx Msg Rcvd
	{
		/* Notification Error */
		Error_Handler();
	}
 
	TxHeader.Identifier = 0x321;
	TxHeader.IdType = FDCAN_STANDARD_ID;
	TxHeader.TxFrameType = FDCAN_DATA_FRAME;
	TxHeader.DataLength = FDCAN_DLC_BYTES_2;
	TxHeader.ErrorStateIndicator = FDCAN_ESI_ACTIVE;
	TxHeader.BitRateSwitch = FDCAN_BRS_OFF;
	TxHeader.FDFormat = FDCAN_CLASSIC_CAN;
	TxHeader.TxEventFifoControl = FDCAN_NO_TX_EVENTS;
	TxHeader.MessageMarker = 0;
	
	// Send
	if (HAL_FDCAN_AddMessageToTxFifoQ(&hfdcan1, &TxFdMessage.stHeader, TxFdMessage.Data) != HAL_OK) 
	{
		/* Transmission request Error */
		Error_Handler();
	}

The only clue or error I can see is that the (24kbps) bitrate isn't what I'd expect (1Mbps) based on the FDCLK of 48Mhz.

The DS12923 document says the CAN BOOTLOADER PINS (PH13/Ph14) is FDCAN1, yet the AN4938 document says it is FDCAN2.

 0693W000000VUWxQAO.jpg

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