2019年09月30日 | STM32F4 CAN2配置

通信协议

基本知识

特别注意 CAN2配置时，滤波器要从[14]开始配置。

代码块

#define CAN2_PORT        CAN2

#define CAN2_GPIO_PORT   GPIOB

#define CAN2_RX_PIN      GPIO_Pin_12

#define CAN2_TX_PIN      GPIO_Pin_13

#define CAN_ID_Chassis   130

struct CAN_Socket

{

  unsigned int    u32_StdId;

  unsigned int    u32_ExtId;

  unsigned char   u8_IDE;

  unsigned char   u8_RTR;

  unsigned char   u8_DLC;

  unsigned char   u8_FMI;

  unsigned char   u8_data[8];

};

typedef struct CAN_Socket CAN;

CAN Send_Socket;

CanRxMsg  RxMessage2;

CanTxMsg  TxMessage2;

void CAN_Data_Init(void)

{

  int i;

  Send_Socket.u32_StdId = CAN_ID_Chassis;

  Send_Socket.u8_IDE = CAN_ID_STD;

  Send_Socket.u8_RTR = CAN_RTR_DATA;

  Send_Socket.u8_DLC = DLC_MAX;

  for(i = 0; i<8; i++)

  {

    Send_Socket.u8_data[i] = 0;

  }

}

void CAN2_Setup()

{

  GPIO_InitTypeDef GPIO_InitStructure;

  CAN_InitTypeDef CAN_InitStructure;

  CAN_FilterInitTypeDef CAN_FilterInitStructure;

  NVIC_InitTypeDef  NVIC_InitStructure;

  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB,ENABLE);

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN2, ENABLE);

  GPIO_InitStructure.GPIO_Pin = CAN2_RX_PIN|CAN2_TX_PIN;

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

  //GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

  //GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;

  GPIO_Init(CAN2_GPIO_PORT, &GPIO_InitStructure);

  GPIO_PinAFConfig(GPIOB, GPIO_PinSource12, GPIO_AF_CAN2); //CAN_RX = PB12

  GPIO_PinAFConfig(GPIOB, GPIO_PinSource13, GPIO_AF_CAN2); //CAN_TX = PB13

  CAN_DeInit(CAN2);

  CAN_StructInit(&CAN_InitStructure);

  /* CAN cell init */

  CAN_InitStructure.CAN_TTCM = DISABLE;

  CAN_InitStructure.CAN_ABOM = DISABLE;

  CAN_InitStructure.CAN_AWUM = DISABLE;

  CAN_InitStructure.CAN_NART = ENABLE;

  CAN_InitStructure.CAN_RFLM = DISABLE;

  CAN_InitStructure.CAN_TXFP = DISABLE;

  CAN_InitStructure.CAN_Mode = CAN_Mode_Normal;

  CAN_InitStructure.CAN_SJW = CAN_SJW_1tq;//同步跳转时间段

  CAN_InitStructure.CAN_BS1 = CAN_BS1_3tq;//时间段1

  CAN_InitStructure.CAN_BS2 = CAN_BS2_3tq;//时间段2

  CAN_InitStructure.CAN_Prescaler = 6;//波特率分频器

  /* CAN 波特率配置 = 42MHz/[(1+3+3)*6] = 1MHz (APB1的时钟频率一般为42MHz)*/

  if(CAN_Init(CAN2, &CAN_InitStructure) == CANINITFAILED)

  {

    do {}

    while(1);

  }

  /* CAN filter init */

  CAN_FilterInitStructure.CAN_FilterNumber = 14;//CAN2的滤波器从14开始

  CAN_FilterInitStructure.CAN_FilterMode = CAN_FilterMode_IdMask;

  CAN_FilterInitStructure.CAN_FilterScale = CAN_FilterScale_32bit;

  CAN_FilterInitStructure.CAN_FilterIdHigh = 0x0000;

  CAN_FilterInitStructure.CAN_FilterIdLow = 0x0000;

  CAN_FilterInitStructure.CAN_FilterMaskIdHigh = 0x0000;

  CAN_FilterInitStructure.CAN_FilterMaskIdLow = 0x0000;

  //  CAN_FilterInitStructure.CAN_FilterFIFOAssignment=0;

  CAN_FilterInitStructure.CAN_FilterFIFOAssignment = CAN_FIFO0;

  CAN_FilterInitStructure.CAN_FilterActivation = ENABLE;

  CAN_FilterInit(&CAN_FilterInitStructure);

  CAN_ITConfig(CAN2, CAN_IT_FMP0, ENABLE);

  NVIC_InitStructure.NVIC_IRQChannel = CAN2_RX0_IRQn;

  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;

  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;

  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

  NVIC_Init(&NVIC_InitStructure);  

}

void CAN2_RX0_IRQHandler(void)

{

  int i;

  RxMessage2.StdId = 0x00;

  RxMessage2.ExtId = 0x00;

  for(i =0; i<8; i++)

  {

    RxMessage2.Data[i] = 0;

  }

  CAN_Receive(CAN2, CAN_FIFO0, &RxMessage2);

  switch(RxMessage2.StdId)

  {

  case 1:

    break;

  case 2:

    break;

  default:

    break;

  }

}

void CAN_TxSocket_CAN2(CAN *can_Socket)

{

  char i = 0;

  TxMessage2.StdId=can_Socket->u32_StdId;

  TxMessage2.ExtId=can_Socket->u32_ExtId;

  TxMessage2.IDE=can_Socket->u8_IDE;

  TxMessage2.RTR= can_Socket->u8_RTR;

  TxMessage2.DLC=can_Socket->u8_DLC;

  for(i =0; i  {

    TxMessage2.Data[i] = can_Socket->u8_data[i];

  }

  i = CAN_Transmit(CAN2, &TxMessage2);

}

int main(void)

{

  CAN2_Setup();

  CAN_Data_Init();

  while(1)

  {

    if(Send_Flag == 1)//这个flag可用一个定时器来计时，这里不做特别说明

    {

      Send_Flag = 0;

      CAN_TxSocket_CAN2(&Send_Socket);//Send_Socket中可以存入要发送的数据

    }

  }

}