MCU_STM32CUBEMX配置生成CAN2的初始化代码的修改

桃扇骨 2023-03-13 12:24 15阅读 0赞

备注一个STM32CUBEMX配置CAN2的遗忘点。

STM32F105/107（405/407）有两个CAN，一般我们两个都会用起来，用STM32CubeMX配置好后，有一个经常容易忘记的地方就是SlaveStartFilterBank这个参数。这里他是最重要的和hcan1不一致的地方，

CAN2\_FilerConf.SlaveStartFilterBank = 14;

这一句必须开启，否则CAN2只能发送数据，无法接收到数据。

这个参数其实设置的是CAN\_FMR\_CAN2SB（参考《RM0008 24.9.4 CAN filter registers》）

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摘录其中比较重要的两句如下，

CAN filter master register (CAN\_FMR)  
Bits 13:8 CAN2SB\[5:0\]: CAN2 start bank  
These bits are set and cleared by software. They define the start bank for the CAN2 interface (Slave) in the range 0 to 27.

Note:  
When CAN2SB\[5:0\] = 28d, all the filters to CAN1 can be used.  
When CAN2SB\[5:0\] is set to 0, no filters are assigned to CAN1.

红色这两句的意思是：  
如果CAN2SB=28，就表示28个过滤器全部分配给CAN1，因为CAN2从28开始，而序号从28开始的过滤器不存在，所以全部28个过滤器都分配给了CAN1。  
如果CAN2SB=0，就表示28个过滤器全部分配给CAN2，因为最小序号0的过滤器分配给了CAN2，后续也只能连续地分配给CAN2。

STM32CUBEMX生成代码后，修改后如下，

/**
      * @brief CAN1 Initialization Function
      * @param None
      * @retval None
      */
    static void MX_CAN1_Init(void)
    {
    
      /* USER CODE BEGIN CAN1_Init 0 */
    	HAL_StatusTypeDef HAL_Status;
    	// NOTE:
        //Prescaler = 4;                    ==> APB1.36M/4 = 9M (original=16)
        //Mode = CAN_MODE_LOOPBACK;         ==> CAN_MODE_NORMAL; //CAN_MODE_LOOPBACK
        //CAN_BS1.2_9TQ/ = CAN_BS1.2_9.8TQ; ==> BaudRate = 9M/(1+9+8) = 500K
      /* USER CODE END CAN1_Init 0 */
    
      /* USER CODE BEGIN CAN1_Init 1 */
    
      /* USER CODE END CAN1_Init 1 */
      hcan1.Instance = CAN1;
      hcan1.Init.Prescaler = 4;
      hcan1.Init.Mode = CAN_MODE_NORMAL;  //CAN_MODE_LOOPBACK
      hcan1.Init.SyncJumpWidth = CAN_SJW_1TQ;
      hcan1.Init.TimeSeg1 = CAN_BS1_9TQ;
      hcan1.Init.TimeSeg2 = CAN_BS2_8TQ;
      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 2 */
    	// added bymc
        // add filter_0 to can_1
    	CAN_Filter.FilterBank = 0;	                    
    	CAN_Filter.FilterMode = CAN_FILTERMODE_IDMASK; 	
    	CAN_Filter.FilterScale= CAN_FILTERSCALE_32BIT; 	// 32BIT WIDTH
    	CAN_Filter.FilterIdHigh = 0x0000;	            // 32BIT ID
    	CAN_Filter.FilterIdLow  = 0x0000;
    	CAN_Filter.FilterMaskIdHigh = 0x0000;           // 32BIT MASK
    	CAN_Filter.FilterMaskIdLow  = 0x0000;
    	CAN_Filter.FilterFIFOAssignment = CAN_FILTER_FIFO0;  //filter_0 -->  FIFO0
        CAN_Filter.FilterActivation = ENABLE;           // NOTE: deactivate it if not used!
    	if( HAL_OK != HAL_CAN_ConfigFilter(&hcan1, &CAN_Filter))
    	{
    		Error_Handler();
    	}
    
    	HAL_Status = HAL_CAN_Start(&hcan1); 
    	if(HAL_Status!=HAL_OK){
    		Error_Handler();
    	}	
    
    	// Activate CAN RX notification (HERE WE attach FIFO0 to CAN1) called "CAN0" in manual
    	if (HAL_CAN_ActivateNotification(&hcan1, CAN_IT_RX_FIFO0_MSG_PENDING) != HAL_OK)
    	{    
    		Error_Handler();
    	}
    
    	// Activate CAN TX notification
    	if (HAL_CAN_ActivateNotification(&hcan1, CAN_IT_TX_MAILBOX_EMPTY) != HAL_OK)
    	{
    		Error_Handler();
    	}	
    	
    	// end added bymc
    
      /* USER CODE END CAN1_Init 2 */
    
    }
    
    /**
      * @brief CAN2 Initialization Function
      * @param None
      * @retval None
      */
    static void MX_CAN2_Init(void)
    {
    
      /* USER CODE BEGIN CAN2_Init 0 */
    	HAL_StatusTypeDef HAL_Status;
      /* USER CODE END CAN2_Init 0 */
    
      /* USER CODE BEGIN CAN2_Init 1 */
    
      /* USER CODE END CAN2_Init 1 */
      hcan2.Instance = CAN2;
      hcan2.Init.Prescaler = 4;
      hcan2.Init.Mode = CAN_MODE_NORMAL;
      hcan2.Init.SyncJumpWidth = CAN_SJW_1TQ;
      hcan2.Init.TimeSeg1 = CAN_BS1_9TQ;
      hcan2.Init.TimeSeg2 = CAN_BS2_8TQ;
      hcan2.Init.TimeTriggeredMode = DISABLE;
      hcan2.Init.AutoBusOff = DISABLE;
      hcan2.Init.AutoWakeUp = DISABLE;
      hcan2.Init.AutoRetransmission = DISABLE;
      hcan2.Init.ReceiveFifoLocked = DISABLE;
      hcan2.Init.TransmitFifoPriority = DISABLE;
      if (HAL_CAN_Init(&hcan2) != HAL_OK)
      {
        Error_Handler();
      }
      /* USER CODE BEGIN CAN2_Init 2 */
    	// added bymc
    	// add filter_0 to can_1
    	CAN_Filter.FilterBank = 14;	                    // <=27       
    	CAN_Filter.FilterMode = CAN_FILTERMODE_IDMASK; 	
    	CAN_Filter.FilterScale= CAN_FILTERSCALE_32BIT; 	// 32BIT WIDTH
    	CAN_Filter.FilterIdHigh = 0x0000;	            // 32BIT ID
    	CAN_Filter.FilterIdLow  = 0x0000;
    	CAN_Filter.FilterMaskIdHigh = 0x0000;           // 32BIT MASK
    	CAN_Filter.FilterMaskIdLow  = 0x0000;
    	CAN_Filter.FilterFIFOAssignment = CAN_FILTER_FIFO1;  //filter_0 -->  FIFO0
    	CAN_Filter.FilterActivation = ENABLE;
    	CAN_Filter.SlaveStartFilterBank = 14;
    	if( HAL_OK != HAL_CAN_ConfigFilter(&hcan2, &CAN_Filter))
    	{
    		Error_Handler();
    	}
    
    	HAL_Status = HAL_CAN_Start(&hcan2); 
    	if(HAL_Status!=HAL_OK){
    		Error_Handler();
    	}	
    
    	// Activate CAN RX notification 
    	if (HAL_CAN_ActivateNotification(&hcan2, CAN_IT_RX_FIFO1_MSG_PENDING) != HAL_OK)
    	{    
    		Error_Handler();
    	}
    
    	// Activate CAN TX notification
    	if (HAL_CAN_ActivateNotification(&hcan2, CAN_IT_TX_MAILBOX_EMPTY) != HAL_OK)
    	{
    		Error_Handler();
    	}
    
    	// end added bymc
    
      /* USER CODE END CAN2_Init 2 */
    
    }

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