[STM32F105R8T6] CAN2 transmit working but receive isn't

[hjm]

I am trying to get dual 500kbps CAN working on the STM32F105R8T6. I am using CubeMX with HAL V1.6.1. CAN1 receive works and CAN2 transmit works but I cannot seem to get the CAN2 Rx interrupt to trigger.

I have probed the Rx pin on the transceiver (MCP2562) and the frames are present but still no interrupt.

Here is the setup code for both modules:

/* CAN1 init function */
void MX_CAN1_Init(void)
{
 
  hcan1.Instance = CAN1;
  hcan1.Init.Prescaler = 1;
  hcan1.Init.Mode = CAN_MODE_NORMAL;
  hcan1.Init.SJW = CAN_SJW_1TQ;
  hcan1.Init.BS1 = CAN_BS1_13TQ;
  hcan1.Init.BS2 = CAN_BS2_2TQ;
  hcan1.Init.TTCM = DISABLE;
  hcan1.Init.ABOM = DISABLE;
  hcan1.Init.AWUM = DISABLE;
  hcan1.Init.NART = DISABLE;
  hcan1.Init.RFLM = DISABLE;
  hcan1.Init.TXFP = DISABLE;
  if (HAL_CAN_Init(&hcan1) != HAL_OK)
  {
    _Error_Handler(__FILE__, __LINE__);
  }
 
  // Configure the filter for CAN 1
  CAN_FilterConfTypeDef sFilterConfig;
  sFilterConfig.FilterNumber = 0;
  sFilterConfig.BankNumber = 14;
  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_FILTER_FIFO0;
  sFilterConfig.FilterActivation = ENABLE;
  if (HAL_CAN_ConfigFilter(&hcan1, &sFilterConfig) != HAL_OK)
  {
      /* Filter configuration Error */
      Error_Handler();
  }
}
/* CAN2 init function */
void MX_CAN2_Init(void)
{
 
  hcan2.Instance = CAN2;
  hcan2.Init.Prescaler = 1;
  hcan2.Init.Mode = CAN_MODE_NORMAL;
  hcan2.Init.SJW = CAN_SJW_1TQ;
  hcan2.Init.BS1 = CAN_BS1_13TQ;
  hcan2.Init.BS2 = CAN_BS2_2TQ;
  hcan2.Init.TTCM = DISABLE;
  hcan2.Init.ABOM = DISABLE;
  hcan2.Init.AWUM = DISABLE;
  hcan2.Init.NART = DISABLE;
  hcan2.Init.RFLM = DISABLE;
  hcan2.Init.TXFP = DISABLE;
  if (HAL_CAN_Init(&hcan2) != HAL_OK)
  {
    _Error_Handler(__FILE__, __LINE__);
  }
 
  // Configure the filter for CAN 2
  CAN_FilterConfTypeDef sFilterConfig;
  sFilterConfig.FilterNumber = 14;
  sFilterConfig.BankNumber = 14;
  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_FILTER_FIFO0;
  sFilterConfig.FilterActivation = ENABLE;
  if (HAL_CAN_ConfigFilter(&hcan2, &sFilterConfig) != HAL_OK)
  {
    /* Filter configuration Error */
    Error_Handler();
  }
}
 
static uint32_t HAL_RCC_CAN1_CLK_ENABLED=0;
 
void HAL_CAN_MspInit(CAN_HandleTypeDef* canHandle)
{
 
  GPIO_InitTypeDef GPIO_InitStruct;
  if(canHandle->Instance==CAN1)
  {
  /* USER CODE BEGIN CAN1_MspInit 0 */
 
    static CanTxMsgTypeDef TxMessage;
    static CanRxMsgTypeDef RxMessage;
    canHandle->pTxMsg = &TxMessage;
    canHandle->pRxMsg = &RxMessage;
 
  /* USER CODE END CAN1_MspInit 0 */
    /* CAN1 clock enable */
    HAL_RCC_CAN1_CLK_ENABLED++;
    if(HAL_RCC_CAN1_CLK_ENABLED==1){
      __HAL_RCC_CAN1_CLK_ENABLE();
    }
  
    /**CAN1 GPIO Configuration    
    PA11     ------> CAN1_RX
    PA12     ------> CAN1_TX 
    */
    GPIO_InitStruct.Pin = GPIO_PIN_11;
    GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
    GPIO_InitStruct.Pull = GPIO_PULLUP;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
 
    GPIO_InitStruct.Pin = GPIO_PIN_12;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
 
    /* CAN1 interrupt Init */
    HAL_NVIC_SetPriority(CAN1_RX0_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(CAN1_RX0_IRQn);
  /* USER CODE BEGIN CAN1_MspInit 1 */
 
  /* USER CODE END CAN1_MspInit 1 */
  }
  else if(canHandle->Instance==CAN2)
  {
  /* USER CODE BEGIN CAN2_MspInit 0 */
 
    static CanTxMsgTypeDef TxMessage;
    static CanRxMsgTypeDef RxMessage;
    canHandle->pTxMsg = &TxMessage;
    canHandle->pRxMsg = &RxMessage;
 
  /* USER CODE END CAN2_MspInit 0 */
    /* CAN2 clock enable */
    __HAL_RCC_CAN2_CLK_ENABLE();
    HAL_RCC_CAN1_CLK_ENABLED++;
    if(HAL_RCC_CAN1_CLK_ENABLED==1){
      __HAL_RCC_CAN1_CLK_ENABLE();
    }
  
    /**CAN2 GPIO Configuration    
    PB5     ------> CAN2_RX
    PB6     ------> CAN2_TX 
    */
    GPIO_InitStruct.Pin = GPIO_PIN_5;
    GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
    GPIO_InitStruct.Pull = GPIO_PULLUP;
    HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
 
    GPIO_InitStruct.Pin = GPIO_PIN_6;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
 
    __HAL_AFIO_REMAP_CAN2_ENABLE();
 
    /* CAN2 interrupt Init */
    HAL_NVIC_SetPriority(CAN2_RX0_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(CAN2_RX0_IRQn);
  /* USER CODE BEGIN CAN2_MspInit 1 */
 
  /* USER CODE END CAN2_MspInit 1 */
  }
}

During my main function initialisation I call:

	if (HAL_CAN_Receive_IT(&hcan1, CAN_FIFO0) != HAL_OK) {
		Error_Handler();
	}
	if (HAL_CAN_Receive_IT(&hcan2, CAN_FIFO0) != HAL_OK) {
		Error_Handler();
	}

My CAN Rx IRQ handlers:

void CAN1_RX0_IRQHandler(void)
{
  /* USER CODE BEGIN CAN1_RX0_IRQn 0 */
 
  /* USER CODE END CAN1_RX0_IRQn 0 */
  HAL_CAN_IRQHandler(&hcan1);
  /* USER CODE BEGIN CAN1_RX0_IRQn 1 */
 
  /* USER CODE END CAN1_RX0_IRQn 1 */
}
 
/**
* @brief This function handles CAN2 RX0 interrupt.
*/
void CAN2_RX0_IRQHandler(void)
{
  /* USER CODE BEGIN CAN2_RX0_IRQn 0 */
 
  /* USER CODE END CAN2_RX0_IRQn 0 */
  HAL_CAN_IRQHandler(&hcan2);
  /* USER CODE BEGIN CAN2_RX0_IRQn 1 */
 
  /* USER CODE END CAN2_RX0_IRQn 1 */
}

And my interrupt callback:

void HAL_CAN_RxCpltCallback(CAN_HandleTypeDef *hcan)
{
        //
        // Process the incoming message
        //
 
	/* Receive */
	if(HAL_CAN_Receive_IT(hcan, CAN_FIFO0) != HAL_OK) {
		Error_Handler();
	}
}

The interrupt handler and callback are being entered for CAN1 receive, however this is not happening for CAN2

[hjm]

Update:

As per this thread (last comment): https://community.st.com/s/question/0D50X00009XkXHxSAN/can2-interrupt-not-working I changed the CAN2 filter initialisation code to initialise off CAN1 (see below) then change the instance back to CAN2 before starting the interrupt. The CAN2 interrupt now triggers once but not again (CAN1 receive and CAN2 transmit still works fine as before) - how can I make it keep triggering on new messages?

  hcan2.Instance = CAN1;
  // Configure the filter for CAN 2
  CAN_FilterConfTypeDef sFilterConfig;
  sFilterConfig.FilterNumber = 14;
  sFilterConfig.BankNumber = 14;
  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_FILTER_FIFO0;
  sFilterConfig.FilterActivation = ENABLE;
  if (HAL_CAN_ConfigFilter(&hcan2, &sFilterConfig) != HAL_OK)
  {
    /* Filter configuration Error */
    Error_Handler();
  }
 
  hcan2.Instance = CAN2;