I am using STM32G491RE - NUCLEO.
Similar to this post - ( https://community.st.com/t5/stm32-mcus-products/reading-data-with-brs-on-fdcan-line/m-p/745625#M266951)
I implemented the function of receiving and transmitting data from the FDCAN line.
I configured my FDCANs with BRS mode everything works fine, the only change that causes errors is when I switch TxHeader.BitRateSwitch = FDCAN_BRS_OFF to ON. Then the FIFO fill up like the chip is not receiving ACK with just this change.
int main(void)
{
.....
MX_FDCAN2_Init();
FDCAN_Config();
while (1)
{
while (HAL_GPIO_ReadPin(BTN_GPIO_Port, BTN_Pin) == KEY_PRESSED)
{
......
if (HAL_FDCAN_AddMessageToTxFifoQ(&hfdcan2, &TxHeader, TxData) != HAL_OK)
{
uint32_t psr = hfdcan2.Instance->PSR;
Error_Handler();
}
HAL_Delay(10);
}
}}
static void MX_FDCAN2_Init(void)
{
hfdcan2.Instance = FDCAN2;
hfdcan2.Init.ClockDivider = FDCAN_CLOCK_DIV1;
hfdcan2.Init.FrameFormat = FDCAN_FRAME_FD_BRS;
hfdcan2.Init.Mode = FDCAN_MODE_NORMAL;
hfdcan2.Init.AutoRetransmission = ENABLE;
hfdcan2.Init.TransmitPause = ENABLE;
hfdcan2.Init.ProtocolException = DISABLE;
hfdcan2.Init.NominalPrescaler = 2;
hfdcan2.Init.NominalSyncJumpWidth = 17;
hfdcan2.Init.NominalTimeSeg1 = 67;
hfdcan2.Init.NominalTimeSeg2 = 17;
hfdcan2.Init.DataPrescaler = 5;
hfdcan2.Init.DataSyncJumpWidth = 6;
hfdcan2.Init.DataTimeSeg1 = 10;
hfdcan2.Init.DataTimeSeg2 = 6;
hfdcan2.Init.StdFiltersNbr = 0;
hfdcan2.Init.ExtFiltersNbr = 0;
hfdcan2.Init.TxFifoQueueMode = FDCAN_TX_FIFO_OPERATION;
HAL_FDCAN_Init(&hfdcan2)
}
static void FDCAN_Config(void)
{
FDCAN_FilterTypeDef sFilterConfig;
sFilterConfig.IdType = FDCAN_EXTENDED_ID;
sFilterConfig.FilterIndex = 0;
sFilterConfig.FilterType = FDCAN_FILTER_RANGE;
sFilterConfig.FilterConfig = FDCAN_FILTER_TO_RXFIFO0;
sFilterConfig.FilterID1 = 0x321;
sFilterConfig.FilterID2 = 0x1FFFFFFF; // 0x7FF;
HAL_FDCAN_ConfigFilter(&hfdcan2, &sFilterConfig)
HAL_FDCAN_ConfigTxDelayCompensation(&hfdcan2, (hfdcan2.Init.DataTimeSeg1 + 3), 0U)
HAL_FDCAN_EnableTxDelayCompensation(&hfdcan2)
HAL_FDCAN_Start(&hfdcan2)
HAL_FDCAN_ActivateNotification(&hfdcan2, FDCAN_IT_RX_FIFO0_NEW_MESSAGE, 0)
TxHeader.Identifier = 0x321;
TxHeader.IdType = FDCAN_EXTENDED_ID;
TxHeader.TxFrameType = FDCAN_DATA_FRAME;
TxHeader.DataLength = FDCAN_DLC_BYTES_2;
TxHeader.ErrorStateIndicator = FDCAN_ESI_PASSIVE;
TxHeader.BitRateSwitch = FDCAN_BRS_ON; /*****THIS OVER HERE********/
TxHeader.FDFormat = FDCAN_FD_CAN;
TxHeader.TxEventFifoControl = FDCAN_NO_TX_EVENTS;
TxHeader.MessageMarker = 0;
}
When I select BRS_ON specifically only on TxHeader, the code runs for 3 loops and on the 4th it enters error_handler at HAL_FDCAN_AddMessageToTxFifoQ. When it is OFF the code runs fine.
I set the Nominal phase to 1Mbps.
I set the Data phase to 2Mbps.
The can transceiver I use is ADM3055EEBZ which is capable of going up to12Mbps, 150ns propagation delay.
I am using the HSE available on the nucleo board at 170MHz.
I even check for the termination resistor on both end of the CANH and CANL both ends at 120 ohms.
But I don't know what went wrong. Can anyone explain in more detail? @mƎALLEm Please help me
Thanks in advance!
