1.0

Core/Inc/stm32f4xx_it.h

@@ -55,7 +55,7 @@ void SVC_Handler(void);
 void DebugMon_Handler(void);
 void PendSV_Handler(void);
 void SysTick_Handler(void);
-void CAN1_RX0_IRQHandler(void);
+void CAN1_TX_IRQHandler(void);
 void TIM6_DAC_IRQHandler(void);
 void OTG_FS_IRQHandler(void);
 /* USER CODE BEGIN EFP */

Core/Src/can.c

@@ -38,10 +38,10 @@ void MX_CAN1_Init(void)
 
   /* USER CODE END CAN1_Init 1 */
   hcan1.Instance = CAN1;
-  hcan1.Init.Prescaler = 6;
+  hcan1.Init.Prescaler = 21;
   hcan1.Init.Mode = CAN_MODE_NORMAL;
   hcan1.Init.SyncJumpWidth = CAN_SJW_1TQ;
-  hcan1.Init.TimeSeg1 = CAN_BS1_5TQ;
+  hcan1.Init.TimeSeg1 = CAN_BS1_6TQ;
   hcan1.Init.TimeSeg2 = CAN_BS2_1TQ;
   hcan1.Init.TimeTriggeredMode = DISABLE;
   hcan1.Init.AutoBusOff = DISABLE;
@@ -84,8 +84,8 @@ void HAL_CAN_MspInit(CAN_HandleTypeDef* canHandle)
     HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
 
     /* CAN1 interrupt Init */
-    HAL_NVIC_SetPriority(CAN1_RX0_IRQn, 2, 0);
+    HAL_NVIC_SetPriority(CAN1_TX_IRQn, 2, 0);
-    HAL_NVIC_EnableIRQ(CAN1_RX0_IRQn);
+    HAL_NVIC_EnableIRQ(CAN1_TX_IRQn);
   /* USER CODE BEGIN CAN1_MspInit 1 */
 
   /* USER CODE END CAN1_MspInit 1 */
@@ -110,7 +110,7 @@ void HAL_CAN_MspDeInit(CAN_HandleTypeDef* canHandle)
     HAL_GPIO_DeInit(GPIOB, GPIO_PIN_8|GPIO_PIN_9);
 
     /* CAN1 interrupt Deinit */
-    HAL_NVIC_DisableIRQ(CAN1_RX0_IRQn);
+    HAL_NVIC_DisableIRQ(CAN1_TX_IRQn);
   /* USER CODE BEGIN CAN1_MspDeInit 1 */
 
   /* USER CODE END CAN1_MspDeInit 1 */

Core/Src/main.c

@@ -50,7 +50,11 @@
 /* Private variables ---------------------------------------------------------*/
 
 /* USER CODE BEGIN PV */
-
+/* USER CODE BEGIN PV */
+CAN_RxHeaderTypeDef RxHeader;
+uint8_t RxData[8];
+volatile uint8_t can_rx_flag = 0; // 告诉主程序“有数据来了”的标志位
+/* USER CODE END PV */
 /* USER CODE END PV */
 
 /* Private function prototypes -----------------------------------------------*/
@@ -62,14 +66,17 @@ void SystemClock_Config(void);
 /* Private user code ---------------------------------------------------------*/
 /* USER CODE BEGIN 0 */
 // 完美解决 USB 忙碌丢包的重定向函数
+// 完美解决 USB 忙碌丢包，且防中断死锁的重定向函数
 int _write(int file, char *ptr, int len) {
   uint8_t result = CDC_Transmit_FS((uint8_t*)ptr, len);
-  uint16_t timeout = 0;
+
-  // 如果 USB 正在忙，最多等 5ms，防止死锁
+  // 使用简单的变量自增来做超时等待，坚决不用 HAL_Delay
-  while(result == USBD_BUSY && timeout < 5) {
+  uint32_t timeout = 0;
-    HAL_Delay(1);
+
-    result = CDC_Transmit_FS((uint8_t*)ptr, len);
+  // 50000 只是一个大概的经验值，纯耗费 CPU 周期
+  while(result == USBD_BUSY && timeout < 50000) {
     timeout++;
+    result = CDC_Transmit_FS((uint8_t*)ptr, len);
   }
   return len;
 }
@@ -116,6 +123,7 @@ int main(void)
   MX_CAN1_Init();
   /* USER CODE BEGIN 2 */
   // 1. 初始化 bxCAN 过滤器 (全通)
+  // 后面的 printf 就能看到了
   CAN_FilterTypeDef canFilterConfig;
   canFilterConfig.FilterBank = 0;
   canFilterConfig.FilterMode = CAN_FILTERMODE_IDMASK;
@@ -127,15 +135,17 @@ int main(void)
   canFilterConfig.FilterFIFOAssignment = CAN_RX_FIFO0;
   canFilterConfig.FilterActivation = ENABLE;
   canFilterConfig.SlaveStartFilterBank = 14;
-  HAL_CAN_ConfigFilter(&hcan1, &canFilterConfig);
 
-  // 2. 启动 CAN 外设
+  HAL_StatusTypeDef fs = HAL_CAN_ConfigFilter(&hcan1, &canFilterConfig);
-  HAL_CAN_Start(&hcan1);
+  printf("Filter: %d\r\n", fs);
 
-  // 3. 开启 RX FIFO0 接收中断
+  HAL_StatusTypeDef ss = HAL_CAN_Start(&hcan1);
-  HAL_CAN_ActivateNotification(&hcan1, CAN_IT_RX_FIFO0_MSG_PENDING);
+  printf("Start: %d\r\n", ss);
 
-  printf("=== F4 CAN Receiver Init OK ===\r\n");
+  HAL_StatusTypeDef ns = HAL_CAN_ActivateNotification(&hcan1, CAN_IT_RX_FIFO0_MSG_PENDING);
+  printf("Notif: %d\r\n", ns);
+
+  printf("=== CAN Ready ===\r\n");
   /* USER CODE END 2 */
 
   /* Infinite loop */
@@ -145,7 +155,17 @@ int main(void)
     /* USER CODE END WHILE */
 
     /* USER CODE BEGIN 3 */
+    // 如果标志位被中断立起来了，说明有新数据
+    if (can_rx_flag == 1) {
+      can_rx_flag = 0; // 赶紧先把标志位清零，防止漏掉下一次
 
+      // 在主循环里悠哉游哉地通过 USB 打印，爱怎么耗时就怎么耗时
+      printf("Got MSG! ID:0x%03lX Data: ", RxHeader.StdId);
+      for(int i = 0; i < RxHeader.DLC; i++) {
+        printf("%02X ", RxData[i]);
+      }
+      printf("\r\n");
+    }
     /* USER CODE END WHILE */
   }
   /* USER CODE END 3 */
@@ -199,17 +219,11 @@ void SystemClock_Config(void)
 /* USER CODE BEGIN 4 */
 void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan)
 {
-  CAN_RxHeaderTypeDef RxHeader;
-  uint8_t RxData[8];
-
   if (hcan->Instance == CAN1) {
+    // 1. 光速把数据从 CAN 硬件 FIFO 里捞出来
     if (HAL_CAN_GetRxMessage(hcan, CAN_RX_FIFO0, &RxHeader, RxData) == HAL_OK) {
-      // 收到数据，原样打印出来
+      // 2. 立起标志位，然后火速退出中断，绝不在这里打印！
-      printf("Got MSG! ID:0x%03lX Data: ", RxHeader.StdId);
+      can_rx_flag = 1;
-      for(int i = 0; i < RxHeader.DLC; i++) {
-        printf("%02X ", RxData[i]);
-      }
-      printf("\r\n");
     }
   }
 }

Core/Src/stm32f4xx_it.c

@@ -201,17 +201,17 @@ void SysTick_Handler(void)
 /******************************************************************************/
 
 /**
-  * @brief This function handles CAN1 RX0 interrupts.
+  * @brief This function handles CAN1 TX interrupts.
   */
-void CAN1_RX0_IRQHandler(void)
+void CAN1_TX_IRQHandler(void)
 {
-  /* USER CODE BEGIN CAN1_RX0_IRQn 0 */
+  /* USER CODE BEGIN CAN1_TX_IRQn 0 */
 
-  /* USER CODE END CAN1_RX0_IRQn 0 */
+  /* USER CODE END CAN1_TX_IRQn 0 */
   HAL_CAN_IRQHandler(&hcan1);
-  /* USER CODE BEGIN CAN1_RX0_IRQn 1 */
+  /* USER CODE BEGIN CAN1_TX_IRQn 1 */
 
-  /* USER CODE END CAN1_RX0_IRQn 1 */
+  /* USER CODE END CAN1_TX_IRQn 1 */
 }
 
 /**

FDR-Core.ioc

@@ -2,12 +2,12 @@
 CAD.formats=
 CAD.pinconfig=
 CAD.provider=
-CAN1.BS1=CAN_BS1_5TQ
+CAN1.BS1=CAN_BS1_6TQ
-CAN1.CalculateBaudRate=1000000
+CAN1.CalculateBaudRate=250000
-CAN1.CalculateTimeBit=1000
+CAN1.CalculateTimeBit=4000
-CAN1.CalculateTimeQuantum=142.85714285714286
+CAN1.CalculateTimeQuantum=500.0
 CAN1.IPParameters=CalculateTimeQuantum,CalculateTimeBit,CalculateBaudRate,Prescaler,BS1
-CAN1.Prescaler=6
+CAN1.Prescaler=21
 File.Version=6
 GPIO.groupedBy=
 KeepUserPlacement=false
@@ -66,7 +66,7 @@ Mcu.UserName=STM32F407VGTx
 MxCube.Version=6.15.0
 MxDb.Version=DB.6.0.150
 NVIC.BusFault_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:false
-NVIC.CAN1_RX0_IRQn=true\:2\:0\:true\:false\:true\:true\:true\:true
+NVIC.CAN1_TX_IRQn=true\:2\:0\:true\:false\:true\:true\:true\:true
 NVIC.DebugMonitor_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:false
 NVIC.ForceEnableDMAVector=true
 NVIC.HardFault_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:false