Why STM32F407 CAN bus Rx interrupt does not fire in normal mode ?

[GLEGR.1]

Hi, this subject has already been treated with other boards in other forums, but libraries and tools have changed since then so i thougth i could open a new question. 

So i use CAN1 bus in the Discovery STM32F407 in order to share data between 2 discovery. I use a classic transceiver SN65HVD234 from Texas Instruments. I configured the Discovery with CubeMX and used CubeIDE. I'm using the HAL Library.

I use the User button to fire an EXTI interuption that call HAL_CAN_AddTxMessage() an writes on the bus. 

Transmitting data works but not Receiving.

The Hardware is working very well as you can see [in the picture][1]. However the end of the frame bothers me a bit, i don't know if this is nominal.

Here's what I found using the debugger : The interruption enabled for FIFO0 never fires and the function HAL_CAN_RxFifo0MsgPendingCallback() is never called. 

So I think the problem comes frome the Filter and its registers that i don't really understand.

here is the configuration code : It does not rise any error handler during the initialization. 

CAN_HandleTypeDef hcan1;
 
 
 
/* CAN1 init function */
 
void MX_CAN1_Init(void)
 
{
 
 
 
	hcan1.Instance = CAN1;
 
	hcan1.Init.Prescaler = 17;
 
	hcan1.Init.Mode = CAN_MODE_NORMAL;
 
	hcan1.Init.SyncJumpWidth = CAN_SJW_1TQ;
 
	hcan1.Init.TimeSeg1 = CAN_BS1_6TQ;
 
	hcan1.Init.TimeSeg2 = CAN_BS2_3TQ;
 
	hcan1.Init.TimeTriggeredMode = DISABLE;
 
	hcan1.Init.AutoBusOff = DISABLE;
 
	hcan1.Init.AutoWakeUp = DISABLE;
 
	hcan1.Init.AutoRetransmission = DISABLE;
 
	hcan1.Init.ReceiveFifoLocked = DISABLE;
 
	hcan1.Init.TransmitFifoPriority = DISABLE;
 
	if (HAL_CAN_Init(&hcan1) != HAL_OK)
 
	{
 
		Error_Handler();
 
	}
 
 
 
	/* USER CODE BEGIN CAN1_Init */
 
	CAN_FilterTypeDef sFilterConfig;
 
 
 
	/*##-2- Configure the CAN Filter ###########################################*/
 
	sFilterConfig.FilterBank = 1;
 
	sFilterConfig.FilterMode = CAN_FILTERMODE_IDMASK;
 
	sFilterConfig.FilterScale = CAN_FILTERSCALE_32BIT;
 
	sFilterConfig.FilterIdHigh = 0x0000;
 
	sFilterConfig.FilterIdLow = 0x0000;
 
	sFilterConfig.FilterMaskIdHigh = 0x0000;
 
	sFilterConfig.FilterMaskIdLow = 0x0000;
 
	sFilterConfig.FilterFIFOAssignment = CAN_RX_FIFO0;
 
	sFilterConfig.FilterActivation = ENABLE;
 
	sFilterConfig.SlaveStartFilterBank = 2;
 
 
 
	if (HAL_CAN_ConfigFilter(&hcan1, &sFilterConfig) != HAL_OK)
 
	{
 
		/* Filter configuration Error */
 
		Error_Handler();
 
	}
 
 
 
	/*##-3- Start the CAN peripheral ###########################################*/
 
	if (HAL_CAN_Start(&hcan1) != HAL_OK)
 
	{
 
		/* Start Error */
 
		Error_Handler();
 
	}
 
	/*##-4- Activate CAN RX notification #######################################*/
 
	if (HAL_CAN_ActivateNotification(&hcan1, CAN_IT_RX_FIFO1_MSG_PENDING)
 
			!= HAL_OK) {
 
		/* Notification Error */
 
		Error_Handler();
 
	}
 
	if (HAL_CAN_ActivateNotification(&hcan1, CAN_IT_RX_FIFO0_MSG_PENDING)
 
			!= HAL_OK) {
 
		/* Notification Error */
 
		Error_Handler();
 
 
 
	}
 
	/*##-5- Configure Transmission process #####################################*/
 
	TxHeader.StdId = 0x321; // 321 MCU1
 
	TxHeader.ExtId = 0x00;
 
	TxHeader.RTR = CAN_RTR_DATA;
 
	TxHeader.IDE = CAN_ID_STD;
 
	TxHeader.DLC = 2;
 
	TxHeader.TransmitGlobalTime = DISABLE;
 
 
 
	/* USER CODE END CAN1_Init */
 
}
 
 
 
void HAL_CAN_MspInit(CAN_HandleTypeDef* canHandle)
 
{
 
 
 
	GPIO_InitTypeDef GPIO_InitStruct = {0};
 
	if(canHandle->Instance==CAN1)
 
	{
 
		/* USER CODE BEGIN CAN1_MspInit 0 */
 
 
 
		/* USER CODE END CAN1_MspInit 0 */
 
		/* CAN1 clock enable */
 
		__HAL_RCC_CAN1_CLK_ENABLE();
 
 
 
		__HAL_RCC_GPIOD_CLK_ENABLE();
 
		/**CAN1 GPIO Configuration
 
  PD0   ------> CAN1_RX
 
  PD1   ------> CAN1_TX
 
		 */
 
		GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_1;
 
		GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
 
		GPIO_InitStruct.Pull = GPIO_NOPULL;
 
		GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
 
		GPIO_InitStruct.Alternate = GPIO_AF9_CAN1;
 
		HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);
 
 
 
		/* USER CODE BEGIN CAN1_MspInit 1 */
 
 
 
		/* CAN1 interrupt Init */
 
		HAL_NVIC_SetPriority(CAN1_RX0_IRQn, 0, 0);
 
		HAL_NVIC_EnableIRQ(CAN1_RX0_IRQn);
 
		HAL_NVIC_SetPriority(CAN1_RX1_IRQn, 0, 0);
 
		HAL_NVIC_EnableIRQ(CAN1_RX1_IRQn);
 
 
 
		/* USER CODE END CAN1_MspInit 1 */
 
	}
 
}

I tried to stick to the [STM32F4][2] Ref manual but it didn't work. 

 [1]: https://i.stack.imgur.com/cm3rp.png

 [2]: https://www.st.com/resource/en/reference_manual/dm00031020-stm32f405415-stm32f407417-stm32f427437-and-stm32f429439-advanced-armbased-32bit-mcus-stmicroelectronics.pdf

[SPati.7]

I am also facing same issue in case of STM32F107x as well. Transmit is working and Recieve is not working. I tried in Loop back mode as well, but no use.

If you got any update, Please let me know.

[GLEGR.1]

So we tried with the old library std but it does not work either. We also tried with STM32F405 microcontrolers . We will keep debugging, maybe it has something to do with the baudrate or internal registers ... I would be very happy if someone had experience with this kind of issues !

[GLEGR.1 · Accepted solution]

Problem Solved ! 

I did'nt really found why it was not working on my first prototype but I faced the same issue with my final PCB. 

However there was a short circuit between the CAN TX and RX on one MCU due to a thin wire of tin !

Even with that problem i had the RX signal on my scope that's why i did'nt thought it was a hard problem ! 

I removed the bad soldering and modifed the prescalers to have a lower baudrate : 150 Kbits/s .

The design finaly worked with this configuration : 

/* Private variables ---------------------------------------------------------*/
CAN_HandleTypeDef hcan1;
 
/* USER CODE BEGIN PV */
CAN_HandleTypeDef hcan1;
CAN_TxHeaderTypeDef pHeader; //declare a specific header for message transmittions
CAN_RxHeaderTypeDef pRxHeader; //declare header for message reception
uint32_t TxMailbox;
uint8_t a,r; //declare byte to be transmitted //declare a receive byte
 
/* USER CODE END PV */
 
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_CAN1_Init(void);
 
/* Private user code ---------------------------------------------------------*/
 
/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{
  /* MCU Configuration--------------------------------------------------------*/
 
  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();
 
  /* Configure the system clock */
  SystemClock_Config();
 
 
  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_CAN1_Init();
  /* USER CODE BEGIN 2 */
  CAN_Config();
  a = 0xff;
  /* USER CODE END 2 */
 
  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */
 
    /* USER CODE BEGIN 3 */
	HAL_Delay(1000);
	//function to add message for transmition
	if(HAL_CAN_AddTxMessage(&hcan1, &pHeader, &a, &TxMailbox) != HAL_OK){
		Error_Handler();
	}
	HAL_GPIO_TogglePin(GPIOA, GPIO_PIN_2);
	HAL_Delay(100);
	HAL_GPIO_TogglePin(GPIOA, GPIO_PIN_2);
 
  }
  /* USER CODE END 3 */
}
 
/**
 * @brief CAN1 Initialization Function
 * @param None
 * @retval None
 */
static void MX_CAN1_Init(void)
{
 
 /* USER CODE BEGIN CAN1_Init 1 */
 /* USER CODE END CAN1_Init 1 */
 hcan1.Instance = CAN1;
 hcan1.Init.Prescaler = 20;
 hcan1.Init.Mode = CAN_MODE_NORMAL;
 hcan1.Init.SyncJumpWidth = CAN_SJW_1TQ;
 hcan1.Init.TimeSeg1 = CAN_BS1_12TQ;
 hcan1.Init.TimeSeg2 = CAN_BS2_1TQ;
 hcan1.Init.TimeTriggeredMode = DISABLE;
 hcan1.Init.AutoBusOff = DISABLE;
 hcan1.Init.AutoWakeUp = DISABLE;
 hcan1.Init.AutoRetransmission = DISABLE;
 hcan1.Init.ReceiveFifoLocked = DISABLE;
 hcan1.Init.TransmitFifoPriority = DISABLE;
 
if (HAL_CAN_Init(&hcan1) != HAL_OK)
 {
  Error_Handler();
 }
 
}
 
/**
 * @brief Configures the CAN.
 * @param None
 * @retval None
 */
 
static void CAN_Config(void)
{
 CAN_FilterTypeDef sFilterConfig;
 
 pHeader.DLC=1; //give message size of 1 byte
 pHeader.IDE=CAN_ID_STD; //set identifier to standard
 pHeader.RTR=CAN_RTR_DATA; //set data type to remote transmission request?
 pHeader.StdId=0x244; //define a standard identifier, used for message identification by filters (switch this for the other microcontroller)
 pHeader.ExtId = 0x01;
 pHeader.TransmitGlobalTime = DISABLE;
 
 //filter one (stack light blink)
 sFilterConfig.FilterFIFOAssignment=CAN_RX_FIFO0; //set fifo assignment
 sFilterConfig.FilterIdHigh = 0x0000;
 sFilterConfig.FilterIdLow = 0x0000;
 sFilterConfig.FilterMaskIdHigh = 0x0000;
 sFilterConfig.FilterMaskIdLow = 0x0000;
 sFilterConfig.FilterScale=CAN_FILTERSCALE_32BIT; //set filter scale
 sFilterConfig.FilterActivation=ENABLE;
 sFilterConfig.FilterBank = 0;
 sFilterConfig.FilterMode = CAN_FILTERMODE_IDMASK;
 sFilterConfig.SlaveStartFilterBank = 14;
 if (HAL_CAN_ConfigFilter(&hcan1, &sFilterConfig) != HAL_OK)
 
  {
 
   /* Filter configuration Error */
 
   Error_Handler();
 
  }
 
  if (HAL_CAN_Start(&hcan1) != HAL_OK)
  {
   /* Start Error */
   Error_Handler();
  }
 if (HAL_CAN_ActivateNotification(&hcan1, CAN_IT_RX_FIFO0_MSG_PENDING) != HAL_OK)
  {
 
   /* Notification Error */
   Error_Handler();
  }
}
 

So setting all the filters to 0 permits to accept all CAN messages and it is working.

For those who face the same issue (according to my experience) :

• Make sure your interruptions and the bus are working in LOOPBACK Mode.
• Visualize your signals on a scope or logic analyser : Bus Line, RX & TX on transceivers and MCU pins.
• Try in a lower baudrate ( 100 Kbits/s).
• Use an online example that works as is (if possible).
• Control your soldering and wiring.