CODEWITHSUNDEEP
cembeddedcan-buscanalyzerstm32h7
Kyle Muehlegg
Kyle Muehlegg

Reputation: 39

CAN Communication: Can Transmit but Not Receive

I am attempting to use my STM32H7B3I-EVAL evaluation board to send and receive CAN communication messages. I am communicating with a Vector CANalayzer (16.0, VN1630A). The CANalyzer is being used both to display messages received from the evaluation board, as well as transmit its own data and send it to the evaluation board.

I am currently running the following C code attached to this.

The CANalyzer sees the data that is being sent in the bode for lines 111-138 in the code. However, when I try to receive data from the CANalyzer and make an LED blink on the evaluation board, it does not work.

The data I'm sending from the CANalyzer:

Message ID: 0x123

Data Length: 8

Data: Alternates between 0x2233445566778899 to 0x1223344556677889 every 2 seconds

I'm unsure why this code is successfully sending data to the CANalyzer but not receiving the data sent from it.

Have I not configured the Rx properly?

Test Code:

while(1)
{
  for (uint16_t i = 0; i < 0xFFFF; i++)
          {

              uint16_t TxData1[] = {i, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55};

              //Add message to Tx FIFO
                TxHeader.Identifier = 0x111;
                TxHeader.IdType = FDCAN_STANDARD_ID;
                TxHeader.TxFrameType = FDCAN_DATA_FRAME;
                TxHeader.DataLength = FDCAN_DLC_BYTES_8;
                TxHeader.ErrorStateIndicator = FDCAN_ESI_PASSIVE;
                TxHeader.BitRateSwitch = FDCAN_BRS_ON;
                TxHeader.FDFormat = FDCAN_FD_CAN;
                TxHeader.TxEventFifoControl = FDCAN_STORE_TX_EVENTS;
                TxHeader.MessageMarker = 0xCC;
                HAL_FDCAN_AddMessageToTxFifoQ(&hfdcan1, &TxHeader, TxData1);
                HAL_Delay(5);

                uint16_t TxData2[] = {i, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55};

                TxHeader.Identifier = 0x135;
                TxHeader.IdType = FDCAN_STANDARD_ID;
                TxHeader.TxFrameType = FDCAN_DATA_FRAME;
                TxHeader.DataLength = FDCAN_DLC_BYTES_8;
                TxHeader.ErrorStateIndicator = FDCAN_ESI_PASSIVE;
                TxHeader.BitRateSwitch = FDCAN_BRS_ON;
                TxHeader.FDFormat = FDCAN_FD_CAN;
                TxHeader.TxEventFifoControl = FDCAN_STORE_TX_EVENTS;
                TxHeader.MessageMarker = 0xCC;
                HAL_FDCAN_AddMessageToTxFifoQ(&hfdcan1, &TxHeader, TxData2);
                HAL_Delay(5);


                HAL_FDCAN_GetRxMessage(&hfdcan1, FDCAN_RX_BUFFER0, &RxHeader, RxData);

                if(BufferCmp8b(TxData3,RxData,8)==0){
                    BSP_LED_Toggle(LED1);
                }
          }

}

CAN Initialization:

static void CAN_Init(){
/* Initializes the FDCAN peripheral in loopback mode */
  hfdcan1.Instance = FDCAN1;
  hfdcan1.Init.FrameFormat = FDCAN_FRAME_CLASSIC;
  hfdcan1.Init.Mode = FDCAN_MODE_NORMAL;
  hfdcan1.Init.AutoRetransmission = ENABLE;
  hfdcan1.Init.TransmitPause = ENABLE;
  hfdcan1.Init.ProtocolException = DISABLE;
  /* Bit time configuration:
    ************************
    Bit time parameter         | Nominal      |  Data
    ---------------------------|--------------|----------------
    fdcan_ker_ck               | 20 MHz       | 20 MHz
    Time_quantum (tq)          | 50 ns        | 50 ns
    Synchronization_segment    | 1 tq         | 1 tq
    Propagation_segment        | 23 tq        | 23 tq
    Phase_segment_1            | 8 tq         | 8 tq
    Phase_segment_2            | 8 tq         | 8 tq
    Synchronization_Jump_width | 8 tq         | 8 tq
    Bit_length                 | 40 tq = 2 �s | 40 tq = 2 �s
    Bit_rate                   | 0.5 MBit/s   | 0.5 MBit/s
  */
  hfdcan1.Init.NominalPrescaler = 0x1; /* tq = NominalPrescaler x (1/fdcan_ker_ck) */
  hfdcan1.Init.NominalSyncJumpWidth = 0x8;
  hfdcan1.Init.NominalTimeSeg1 = 0x1F; /* NominalTimeSeg1 = Propagation_segment + Phase_segment_1 */
  hfdcan1.Init.NominalTimeSeg2 = 0x8;
  hfdcan1.Init.DataPrescaler = 0x1;
  hfdcan1.Init.DataSyncJumpWidth = 0x8;
  hfdcan1.Init.DataTimeSeg1 = 0x1F; /* DataTimeSeg1 = Propagation_segment + Phase_segment_1 */
  hfdcan1.Init.DataTimeSeg2 = 0x8;
  hfdcan1.Init.MessageRAMOffset = 0;
  hfdcan1.Init.StdFiltersNbr = 1;
  hfdcan1.Init.ExtFiltersNbr = 1;
  hfdcan1.Init.RxFifo0ElmtsNbr = 1;
  hfdcan1.Init.RxFifo0ElmtSize = FDCAN_DATA_BYTES_8;
  hfdcan1.Init.RxFifo1ElmtsNbr = 2;
  hfdcan1.Init.RxFifo1ElmtSize = FDCAN_DATA_BYTES_8;
  hfdcan1.Init.RxBuffersNbr = 1;
  hfdcan1.Init.RxBufferSize = FDCAN_DATA_BYTES_8;
  hfdcan1.Init.TxEventsNbr = 2;
  hfdcan1.Init.TxBuffersNbr = 1;
  hfdcan1.Init.TxFifoQueueElmtsNbr = 2;
  hfdcan1.Init.TxFifoQueueMode = FDCAN_TX_FIFO_OPERATION;
  hfdcan1.Init.TxElmtSize = FDCAN_DATA_BYTES_8;
  HAL_FDCAN_Init(&hfdcan1);
  }

static void CAN_RxStdFilter_Init(){
  sFilterConfig.IdType = FDCAN_STANDARD_ID;
  sFilterConfig.FilterIndex = 0;
  sFilterConfig.FilterType = FDCAN_FILTER_DUAL;
  sFilterConfig.FilterConfig = FDCAN_FILTER_TO_RXBUFFER;
  sFilterConfig.FilterID1 = 0x111;
  sFilterConfig.FilterID2 = 0x555;
  sFilterConfig.RxBufferIndex = 0;
  HAL_FDCAN_ConfigFilter(&hfdcan1, &sFilterConfig);

}

static void CAN_RxExtFilter_Init(){
  sFilterConfig.IdType = FDCAN_EXTENDED_ID;
  sFilterConfig.FilterIndex = 0;
  sFilterConfig.FilterType = FDCAN_FILTER_RANGE_NO_EIDM;
  sFilterConfig.FilterConfig = FDCAN_FILTER_TO_RXFIFO1;
  sFilterConfig.FilterID1 = 0x1111111;
  sFilterConfig.FilterID2 = 0x2222222;
  HAL_FDCAN_ConfigFilter(&hfdcan1, &sFilterConfig);

}

static void CAN_TxFilter_Init(){
  TxHeader.Identifier = 0x111;
  TxHeader.IdType = FDCAN_STANDARD_ID;
  TxHeader.TxFrameType = FDCAN_DATA_FRAME;
  TxHeader.DataLength = FDCAN_DLC_BYTES_8;
  TxHeader.ErrorStateIndicator = FDCAN_ESI_ACTIVE;
  TxHeader.BitRateSwitch = FDCAN_BRS_ON;
  TxHeader.FDFormat = FDCAN_FD_CAN;
  TxHeader.TxEventFifoControl = FDCAN_STORE_TX_EVENTS;
  TxHeader.MessageMarker = 0x52;
  HAL_FDCAN_AddMessageToTxBuffer(&hfdcan1, &TxHeader, TxData0, FDCAN_TX_BUFFER0);

}

Upvotes: 0

Views: 933

Answers (1)

kesselhaus
kesselhaus

Reputation: 1496

I have no clue about how that HAL you use handles it, but, there is an AppNote for STM32 FDCAN [https://www.st.com/resource/en/application_note/an5348-fdcan-peripheral-on-stm32-devices-stmicroelectronics.pdf], and on page 14 table 5, it has 4 example filters.

The "Second" filter has SFT = "01 - DUAL" and ID1 and ID2 each contain a CAN-ID, which are filtered for 2 messages, and they are stored then to Rx FIFO1 (SFEC = "010 - Store in FIFO1").

The "Third" filter has SFT being ignored ("xx - Don't care"), because SFEC = "111 - Store in Rx Buffer"), where in ID1 the CAN-ID is configured, and ID2 is used to set the BufferId to store that message to.

But in both of these filters, I think ID1 should contain 0x123, since this is the message, you want to receive from your CANalyzer.

static void CAN_RxStdFilter_Init(){
    sFilterConfig.IdType = FDCAN_STANDARD_ID;
    sFilterConfig.FilterIndex = 0;
    sFilterConfig.FilterType = FDCAN_FILTER_DUAL; // <- AppNote SFT field - how does the HAL handle it?
    sFilterConfig.FilterConfig = FDCAN_FILTER_TO_RXBUFFER; // <- AppNote SFEC field 
    sFilterConfig.FilterID1 = 0x111; // <-- 0x123 ??
    sFilterConfig.FilterID2 = 0x555; // <-- 0 ( == RxBufferIndex, when filter to buffer)?
    sFilterConfig.RxBufferIndex = 0;
    HAL_FDCAN_ConfigFilter(&hfdcan1, &sFilterConfig);
}

Not sure, how the HAL handles the FilterType and FilterConfig, there might be a documentation?

Upvotes: 0

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