SCM CAN bus data self-transmitting

1 Introduction

Use STM32F407IGHX single-chip microcomputer (C board) CAN1, CAN2 to short circuit for data self-transmission.

2. CubeMax initialization configuration

Introduction to CAN communication: CAN bus and microcontroller .

1. rcc configuration

2.sys configuration

3. Clock tree configuration

4. CAN configuration

It should be noted that the sixth point, according to the C-board manual, CAN1 output interface is PD0, PD1, as shown in the following figure:

CAN2 configuration is consistent with CAN1, no need to configure pins separately, C board CAN2 output pins are consistent with the default configuration.

5. Trigger button configuration

6. File export

3 Keil terminal program writing

3.1. Initial configuration

1. Filter configuration

To use the CAN bus, you first need to configure the filter.

/* USER CODE BEGIN 4 */
//CAN初始化
void CAN_ConfigFilter()
{
//过滤器配置
  CAN_FilterTypeDef sFilterConfig;//建立过滤器结构体
  sFilterConfig.FilterActivation = CAN_FILTER_ENABLE;
  sFilterConfig.FilterBank = 0;
  sFilterConfig.FilterFIFOAssignment = CAN_FilterFIFO0;
  sFilterConfig.FilterMode = CAN_FILTERMODE_IDMASK;
  sFilterConfig.FilterScale = CAN_FILTERSCALE_32BIT;
  sFilterConfig.FilterIdHigh = 0x0000;//32 位 ID          不使用过滤器
  sFilterConfig.FilterIdLow = 0x0000;
  sFilterConfig.FilterMaskIdHigh = 0x0000;//32 位 MASK
  sFilterConfig.FilterMaskIdLow = 0x0000;    
  sFilterConfig.SlaveStartFilterBank = 14;
   if(HAL_CAN_ConfigFilter(&hcan1, &sFilterConfig) != HAL_OK)
  {
    Error_Handler();
  }
  sFilterConfig.FilterBank = 14;
    if(HAL_CAN_ConfigFilter(&hcan2, &sFilterConfig) != HAL_OK)
  {
    Error_Handler();
  }
}
/* USER CODE END 4 */

2. CAN startup configuration

After the filter configuration, carry out the CAN startup configuration, first start CAN1 and then start CAN2, the code is as follows:

    if(HAL_CAN_ConfigFilter(&hcan2, &sFilterConfig) != HAL_OK)
    {
    Error_Handler();
    }
    //启动CAN
    if(HAL_CAN_Start(&hcan1)!= HAL_OK)
    {
        Error_Handler();
    }
    if(HAL_CAN_Start(&hcan2)!= HAL_OK)
    {
        Error_Handler();
    }

3. Turn on interrupt

After CAN starts, perform CAN interrupt configuration, the code is as follows:

    //打开接收中断
    if(HAL_CAN_ActivateNotification(&hcan1,CAN_IT_RX_FIFO0_MSG_PENDING|CAN_IT_RX_FIFO1_MSG_PENDING)!= HAL_OK)
    {
        Error_Handler();
    }
    if(HAL_CAN_ActivateNotification(&hcan2,CAN_IT_RX_FIFO0_MSG_PENDING|CAN_IT_RX_FIFO1_MSG_PENDING)!= HAL_OK)
    {
        Error_Handler();
    }

The entire initialization function code is as follows:

//CAN初始化
void CAN_ConfigFilter()
{
    //过滤器配置
    CAN_FilterTypeDef sFilterConfig;//建立过滤器结构体
    sFilterConfig.FilterActivation = CAN_FILTER_ENABLE;
    sFilterConfig.FilterBank = 0;
    sFilterConfig.FilterFIFOAssignment = CAN_FilterFIFO0;
    sFilterConfig.FilterMode = CAN_FILTERMODE_IDMASK;
    sFilterConfig.FilterScale = CAN_FILTERSCALE_32BIT;
    sFilterConfig.FilterIdHigh = 0x0000;//32 位 ID          不使用过滤器
  sFilterConfig.FilterIdLow = 0x0000;
  sFilterConfig.FilterMaskIdHigh = 0x0000;//32 位 MASK
  sFilterConfig.FilterMaskIdLow = 0x0000;    
  sFilterConfig.SlaveStartFilterBank = 14;
    
   if(HAL_CAN_ConfigFilter(&hcan1, &sFilterConfig) != HAL_OK)
  {
    Error_Handler();
  }
  sFilterConfig.FilterBank = 14;
    if(HAL_CAN_ConfigFilter(&hcan2, &sFilterConfig) != HAL_OK)
  {
    Error_Handler();
  }
    //启动CAN
    if(HAL_CAN_Start(&hcan1)!= HAL_OK)
    {
        Error_Handler();
    }
    if(HAL_CAN_Start(&hcan2)!= HAL_OK)
    {
        Error_Handler();
    }
    //打开接收中断
    if(HAL_CAN_ActivateNotification(&hcan1,CAN_IT_RX_FIFO0_MSG_PENDING|CAN_IT_RX_FIFO1_MSG_PENDING)!= HAL_OK)
    {
        Error_Handler();
    }
    if(HAL_CAN_ActivateNotification(&hcan2,CAN_IT_RX_FIFO0_MSG_PENDING|CAN_IT_RX_FIFO1_MSG_PENDING)!= HAL_OK)
    {
        Error_Handler();
    }
}
/* USER CODE END 4 */

4. Function declaration and main function call

Declare the appeal function in main.h, as follows:

/* USER CODE BEGIN Includes */
void CAN_ConfigFilter();
/* USER CODE END Includes */

After the declaration, initialize it in the main function, as follows:

/* USER CODE BEGIN 2 */
  CAN_ConfigFilter();
  /* USER CODE END 2 */

5. Define arrays, send and receive structures

/* USER CODE BEGIN PV */
uint8_t txData[8],rxData0[8],rxData1[8];
CAN_TxHeaderTypeDef txHeader;
CAN_RxHeaderTypeDef rxHeader0,rxHeader1;
bool Pa0Pressed = false;
uint16_t txID = 0x200;
uint32_t txMailbox;
/* USER CODE END PV */

6. Button trigger

reference header file

/* USER CODE BEGIN Includes */
#include "stdbool.h"
/* USER CODE END Includes */

7. CAN configuration

while (1)
  {
        if(HAL_GPIO_ReadPin(GPIOA,GPIO_PIN_0) == 0 && !Pa0Pressed){
            Pa0Pressed = true;
            txHeader.StdId = txID;
        txHeader.IDE = CAN_ID_STD;
        txHeader.RTR = CAN_RTR_DATA;
        txHeader.DLC = 8;
            *((uint32_t*)(txData)) = HAL_GetTick();
            if(HAL_CAN_GetTxMailboxesFreeLevel(&hcan1) != 0){
                HAL_CAN_AddTxMessage(&hcan1,&txHeader,txData,&txMailbox);
            }
        }
        else if(HAL_GPIO_ReadPin(GPIOA,GPIO_PIN_0) == 1 && !Pa0Pressed){
            Pa0Pressed = false;
        }
        HAL_Delay(100);

8 Interrupt callback function

/* USER CODE BEGIN 4 */
void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan)
{
    if(hcan->Instance==CAN2)
    {
        HAL_CAN_GetRxMessage(&hcan2,CAN_FILTER_FIFO0,&rxHeader0,rxData0);//获取数据
    }
}
void HAL_CAN_RxFifo10MsgPendingCallback(CAN_HandleTypeDef *hcan)
{
    if(hcan->Instance==CAN2)
    {
        HAL_CAN_GetRxMessage(&hcan1,CAN_FILTER_FIFO1,&rxHeader1,rxData1);//获取数据
    }
 
}