一.CAN基础知识

CAN收发模式

①常规模式：

从总线发送，从总线接收

②回环模式：

向总线和本机发送，只从本机接收。（只发不收）

③静默模式：

不向总线发送，只向本机发送。从总线和本机接收。（只收不发）

④回环静默模式：

不向总线发送，不从总线接收。（自收自发）

（2）构成

        CAN总线使用双绞线进行差分电压传输。两条信号线分别是CAN高（CAN_H）和CAN低（CAN_L）。

        逻辑0为显性电平，逻辑1为隐性电平。

Controller Area Network，控制器局域网络。

二.发送

cubemx

CAN总线波特率=APB1/[(TQ1+TQ2+SS)*Prascaler]

代码

/* USER CODE BEGIN PTD */
void SystemClock_Config(void);
void MX_bsp_CAN_Master_Init(void);
void bsp_CAN_Master_Transmit(uint8_t *pData);
/* USER CODE END PTD */
/* USER CODE BEGIN PD */
#define Master_FilterID   0x321  
#define CAN1_TX_StdID     0x123
/* USER CODE END PD */
/* USER CODE BEGIN PV */
CAN_TxHeaderTypeDef        MasterTxMessage;
CAN_RxHeaderTypeDef        MasterRxMessage;
CAN_TxHeaderTypeDef        SlaveTxMessage;
CAN_RxHeaderTypeDef        SlaveRxMessage;

uint32_t TxMailbox;
/* USER CODE END PV */
 /* USER CODE BEGIN 2 */
  MX_bsp_CAN_Master_Init(); 
  
  /* USER CODE END 2 */
 /* USER CODE BEGIN 3 */
    uint8_t txData[8] = {0x55,0x22,0x33,0x44,0x55,0x66,0x77,0x88};
    bsp_CAN_Master_Transmit(txData);
    HAL_Delay(1000);
  }
  /* USER CODE END 3 */
/* USER CODE BEGIN 4 */
void MX_bsp_CAN_Master_Init(void)
{
	/*配置can通信过滤噿*/
	CAN_FilterTypeDef sFilterCfg;
	
	sFilterCfg.FilterActivation = CAN_FILTER_ENABLE;
	sFilterCfg.FilterBank = 0;
	sFilterCfg.FilterFIFOAssignment = CAN_FILTER_FIFO0;
	sFilterCfg.FilterIdHigh = (((uint32_t)Master_FilterID<<21)&0xFFFF0000)>>16;
	sFilterCfg.FilterIdLow = (((uint32_t)Master_FilterID<<21)|CAN_ID_STD|CAN_RTR_DATA)&0xFFFF;
	sFilterCfg.FilterMaskIdHigh = 0xFFFF;
	sFilterCfg.FilterMaskIdLow = 0xFFFF;
	sFilterCfg.FilterMode = CAN_FILTERMODE_IDMASK;
	sFilterCfg.FilterScale = CAN_FILTERSCALE_32BIT;
	sFilterCfg.SlaveStartFilterBank = 13;
	
	HAL_CAN_ConfigFilter(&hcan1,&sFilterCfg);
	
	HAL_NVIC_SetPriority(CAN1_RX0_IRQn,0,0);
	HAL_NVIC_EnableIRQ(CAN1_RX0_IRQn);
	
	HAL_CAN_Start(&hcan1);
	
	HAL_CAN_ActivateNotification(&hcan1,CAN_IT_RX_FIFO0_MSG_PENDING);
}
//发送函数
void bsp_CAN_Master_Transmit(uint8_t *pData)
{
	MasterTxMessage.DLC				= 8;
	MasterTxMessage.StdId     = CAN1_TX_StdID;
	MasterTxMessage.IDE				= CAN_ID_STD;
	MasterTxMessage.RTR				= CAN_RTR_DATA;
	if(HAL_CAN_AddTxMessage(&hcan1,&MasterTxMessage,pData,&TxMailbox) != HAL_OK) {
		Error_Handler();
	}
}
/* USER CODE END 4 */

结果

发送数字

发送字符

注意：示波器解码设置

三.CAN1发送数据，CAN2接收数据

cubemx

代码

can1发送数据can2接收数据，并在中断回调函数中将接收的数据通过串口传输观察

/* USER CODE BEGIN PTD */
void SystemClock_Config(void);
void MX_bsp_CAN_Master_Init(void);
void MX_bsp_CAN2_Master_Init(void);
void bsp_CAN_Master_Transmit(uint8_t *pData);
/* USER CODE END PTD */
/* USER CODE BEGIN PD */
#define Master_FilterID   0x321  
#define CAN1_TX_StdID     0x123
#define CAN2_RX_StdID     0x123  // 与CAN1发送ID一致，才能接收（补充定义）
/* USER CODE END PD */
/* USER CODE BEGIN PV */
CAN_TxHeaderTypeDef        MasterTxMessage;
CAN_RxHeaderTypeDef        MasterRxMessage;
CAN_TxHeaderTypeDef        SlaveTxMessage;
CAN_RxHeaderTypeDef        SlaveRxMessage;

uint32_t TxMailbox;
uint8_t SlaveRxData[8];  // 用于存储CAN2接收的数据

/* USER CODE END PV */
 /* USER CODE BEGIN 2 */
  MX_bsp_CAN_Master_Init(); 
  MX_bsp_CAN2_Master_Init(); 

  /* USER CODE END 2 */
    /* USER CODE BEGIN 3 */
	uint8_t txData[8] = {'h','e','l','l','o'};
    bsp_CAN_Master_Transmit(txData);
    HAL_Delay(1000);
  }
  /* USER CODE END 3 */
/* USER CODE BEGIN 4 */
void MX_bsp_CAN_Master_Init(void)
{
	CAN_FilterTypeDef sFilterCfg;
	
	sFilterCfg.FilterActivation = CAN_FILTER_ENABLE;
	sFilterCfg.FilterBank = 0;
	sFilterCfg.FilterFIFOAssignment = CAN_FILTER_FIFO0;
	sFilterCfg.FilterIdHigh = (((uint32_t)Master_FilterID<<21)&0xFFFF0000)>>16;
	sFilterCfg.FilterIdLow = (((uint32_t)Master_FilterID<<21)|CAN_ID_STD|CAN_RTR_DATA)&0xFFFF;
	sFilterCfg.FilterMaskIdHigh = 0xFFFF;
	sFilterCfg.FilterMaskIdLow = 0xFFFF;
	sFilterCfg.FilterMode = CAN_FILTERMODE_IDMASK;
	sFilterCfg.FilterScale = CAN_FILTERSCALE_32BIT;
	sFilterCfg.SlaveStartFilterBank = 13;
	
	HAL_CAN_ConfigFilter(&hcan1,&sFilterCfg);
	
	HAL_NVIC_SetPriority(CAN1_RX0_IRQn,0,0);
	HAL_NVIC_EnableIRQ(CAN1_RX0_IRQn);
	
	HAL_CAN_Start(&hcan1);
	
	HAL_CAN_ActivateNotification(&hcan1,CAN_IT_RX_FIFO0_MSG_PENDING);
}
void MX_bsp_CAN2_Master_Init(void)
{
	CAN_FilterTypeDef sFilterCfg;
	
	sFilterCfg.FilterActivation = CAN_FILTER_ENABLE;
	sFilterCfg.FilterBank = 13;
	sFilterCfg.FilterFIFOAssignment = CAN_FILTER_FIFO0;
	sFilterCfg.FilterIdHigh = (((uint32_t)Master_FilterID<<21)&0xFFFF0000)>>16;
	sFilterCfg.FilterIdLow = (((uint32_t)Master_FilterID<<21)|CAN_ID_STD|CAN_RTR_DATA)&0xFFFF;
	sFilterCfg.FilterMaskIdHigh = 0xFFFF;
	sFilterCfg.FilterMaskIdLow = 0xFFFF;
	sFilterCfg.FilterMode = CAN_FILTERMODE_IDMASK;
	sFilterCfg.FilterScale = CAN_FILTERSCALE_32BIT;
	sFilterCfg.SlaveStartFilterBank = 13;
	
	HAL_CAN_ConfigFilter(&hcan2,&sFilterCfg);
	
	HAL_NVIC_SetPriority(CAN2_RX0_IRQn,0,0);
	HAL_NVIC_EnableIRQ(CAN2_RX0_IRQn);
	
	HAL_CAN_Start(&hcan2);
	
	HAL_CAN_ActivateNotification(&hcan2,CAN_IT_RX_FIFO0_MSG_PENDING);
}

void bsp_CAN_Master_Transmit(uint8_t *pData)
{
	MasterTxMessage.DLC				= 8;
	MasterTxMessage.StdId     = CAN1_TX_StdID;
	MasterTxMessage.IDE				= CAN_ID_STD;
	MasterTxMessage.RTR				= CAN_RTR_DATA;
	if(HAL_CAN_AddTxMessage(&hcan1,&MasterTxMessage,pData,&TxMailbox) != HAL_OK) {
		Error_Handler();
	}
}
//接收中断
void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan)
{
    if(hcan->Instance == CAN2)  
    {
        HAL_CAN_GetRxMessage(hcan, CAN_RX_FIFO0, &SlaveRxMessage, SlaveRxData);
        
        if(SlaveRxMessage.StdId == CAN1_TX_StdID)
        {
			HAL_UART_Transmit(&huart1, SlaveRxData, 5, 50); 
            
            uint8_t enter[] = {'\r', '\n'};  
            HAL_UART_Transmit(&huart1, enter, 2, 50);
        }
    }
}

/* USER CODE END 4 */

结果

发送“hello”

发送数字

四.can2发给can1

同理

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2025 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "can.h"
#include "usart.h"
#include "gpio.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
void SystemClock_Config(void);
void MX_bsp_CAN_Master_Init(void);
void MX_bsp_CAN2_Master_Init(void);
void bsp_CAN2_Transmit(uint8_t *pData);  
/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
#define Master_FilterID   0x123  
#define CAN2_TX_StdID     0x123  
#define CAN1_RX_StdID     0x123
/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/

/* USER CODE BEGIN PV */
CAN_TxHeaderTypeDef        MasterTxMessage;
CAN_RxHeaderTypeDef        MasterRxMessage;
CAN_TxHeaderTypeDef        SlaveTxMessage;
CAN_RxHeaderTypeDef        SlaveRxMessage;

uint32_t TxMailbox;
uint8_t MasterRxData[8];  

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{

  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_CAN1_Init();
  MX_CAN2_Init();
  MX_USART1_UART_Init();
  /* USER CODE BEGIN 2 */
  MX_bsp_CAN_Master_Init();  // CAN1初始化（接收端）
  MX_bsp_CAN2_Master_Init(); // CAN2初始化（发送端）

  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
    uint8_t txData[8] = {0x55,0x66,0x77,0x88};
    bsp_CAN2_Transmit(txData);  // 用CAN2发送数据
    HAL_Delay(500);
  }
  /* USER CODE END 3 */
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Configure the main internal regulator output voltage
  */
  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = 25;
  RCC_OscInitStruct.PLL.PLLN = 336;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = 4;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK)
  {
    Error_Handler();
  }
}

/* USER CODE BEGIN 4 */
void MX_bsp_CAN_Master_Init(void)  // CAN1初始化（接收端）
{
  CAN_FilterTypeDef sFilterCfg;
  
  sFilterCfg.FilterActivation = CAN_FILTER_ENABLE;
  sFilterCfg.FilterBank = 0;
  sFilterCfg.FilterFIFOAssignment = CAN_FILTER_FIFO0;
  sFilterCfg.FilterIdHigh = (((uint32_t)Master_FilterID<<21)&0xFFFF0000)>>16;
  sFilterCfg.FilterIdLow = (((uint32_t)Master_FilterID<<21)|CAN_ID_STD|CAN_RTR_DATA)&0xFFFF;
  sFilterCfg.FilterMaskIdHigh = 0xFFFF;
  sFilterCfg.FilterMaskIdLow = 0xFFFF;
  sFilterCfg.FilterMode = CAN_FILTERMODE_IDMASK;
  sFilterCfg.FilterScale = CAN_FILTERSCALE_32BIT;
  sFilterCfg.SlaveStartFilterBank = 13;
  
  HAL_CAN_ConfigFilter(&hcan1,&sFilterCfg);  // 配置CAN1过滤器
  
  HAL_NVIC_SetPriority(CAN1_RX0_IRQn,0,0);  // 配置CAN1中断
  HAL_NVIC_EnableIRQ(CAN1_RX0_IRQn);
  
  HAL_CAN_Start(&hcan1);  // 启动CAN1
  
  HAL_CAN_ActivateNotification(&hcan1,CAN_IT_RX_FIFO0_MSG_PENDING);  // 使能CAN1接收中断
}

void MX_bsp_CAN2_Master_Init(void)  // CAN2初始化（发送端，过滤器可保持配置或简化）
{
  CAN_FilterTypeDef sFilterCfg;
  
  sFilterCfg.FilterActivation = CAN_FILTER_ENABLE;
  sFilterCfg.FilterBank = 13;
  sFilterCfg.FilterFIFOAssignment = CAN_FILTER_FIFO0;
  sFilterCfg.FilterIdHigh = (((uint32_t)Master_FilterID<<21)&0xFFFF0000)>>16;
  sFilterCfg.FilterIdLow = (((uint32_t)Master_FilterID<<21)|CAN_ID_STD|CAN_RTR_DATA)&0xFFFF;
  sFilterCfg.FilterMaskIdHigh = 0xFFFF;
  sFilterCfg.FilterMaskIdLow = 0xFFFF;
  sFilterCfg.FilterMode = CAN_FILTERMODE_IDMASK;
  sFilterCfg.FilterScale = CAN_FILTERSCALE_32BIT;
  sFilterCfg.SlaveStartFilterBank = 13;
  
  HAL_CAN_ConfigFilter(&hcan2,&sFilterCfg);  // 配置CAN2过滤器
  
  HAL_NVIC_SetPriority(CAN2_RX0_IRQn,0,0);  // 配置CAN2中断（如果需要接收功能）
  HAL_NVIC_EnableIRQ(CAN2_RX0_IRQn);
  
  HAL_CAN_Start(&hcan2);  // 启动CAN2
  
  HAL_CAN_ActivateNotification(&hcan2,CAN_IT_RX_FIFO0_MSG_PENDING);  // 使能CAN2接收中断（如果需要）
}

// CAN2发送函数
void bsp_CAN2_Transmit(uint8_t *pData)
{
  SlaveTxMessage.DLC        = 8;  // 数据长度8字节
  SlaveTxMessage.StdId      = CAN2_TX_StdID;  // 使用CAN2发送ID
  SlaveTxMessage.IDE        = CAN_ID_STD;  // 标准帧
  SlaveTxMessage.RTR        = CAN_RTR_DATA;  // 数据帧
  if(HAL_CAN_AddTxMessage(&hcan2,&SlaveTxMessage,pData,&TxMailbox) != HAL_OK) {  // 发送目标改为CAN2
    Error_Handler();
  }
}

// 接收中断回调函数（改为处理CAN1的接收）
void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan)
{
  if(hcan->Instance == CAN1)  // 判断是CAN1的接收中断
  {
    HAL_CAN_GetRxMessage(hcan, CAN_RX_FIFO0, &MasterRxMessage, MasterRxData);  // 读取CAN1接收的数据
    
    if(MasterRxMessage.StdId == CAN2_TX_StdID)  // 验证是否是CAN2发送的ID
    {
      HAL_UART_Transmit(&huart1, MasterRxData, 4, 50);  // 发送接收到的4字节数据（0x55,0x66,0x77,0x88）
      
      uint8_t enter[] = {'\r', '\n'};  
      HAL_UART_Transmit(&huart1, enter, 2, 50);
    }
  }
}

/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler_Debug */
  /* User can add his own implementation to report the HAL error return state */
  __disable_irq();
  while (1)
  {
  }
  /* USER CODE END Error_Handler_Debug */
}

#ifdef  USE_FULL_ASSERT
/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{
  /* USER CODE BEGIN 6 */
  /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */

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