Question

我使用STM32F429 CAN总线程序，TJA1041A作为CAN Transreciver。问题是消息没有得到承认，因此我我附上代码以供进一步参考。我正在使用PCAN View查看我希望检查代码并告诉我是否有任何错误。

代码： -

int main(void)
{

 RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN1, ENABLE);
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN2, ENABLE);

// SystemInit();

    GPIO_InitTypeDef GPIO_InitDef;
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
    GPIO_InitDef.GPIO_Pin = GPIO_Pin_12 | GPIO_Pin_13;
    GPIO_InitDef.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitDef.GPIO_OType = GPIO_OType_PP;
    GPIO_InitDef.GPIO_PuPd = GPIO_PuPd_UP;
    GPIO_InitDef.GPIO_Speed = GPIO_Speed_100MHz;
   GPIO_Init(GPIOB, &GPIO_InitDef);

/* Connect CAN pins to AF */
  GPIO_PinAFConfig(GPIOB, GPIO_PinSource12, GPIO_AF_CAN2); // CAN2_RX
  GPIO_PinAFConfig(GPIOB, GPIO_PinSource13, GPIO_AF_CAN2); // CAN2_TX

  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);

   GPIO_InitDef.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_7;
    GPIO_InitDef.GPIO_Mode = GPIO_Mode_OUT;
    GPIO_InitDef.GPIO_OType = GPIO_OType_PP;
    GPIO_InitDef.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_InitDef.GPIO_Speed = GPIO_Speed_100MHz;

  /* Connect PD5 and PD7 pins  for CAN Transreceiver to enable and 
stanby */

 GPIO_Init(GPIOD, &GPIO_InitDef);
     GPIO_SetBits(GPIOD, GPIO_Pin_5|GPIO_Pin_7);

   RCC_ClocksTypeDef     RCC_Clocks;
  CAN_InitTypeDef       CAN_InitStructure;
  CAN_FilterInitTypeDef CAN_FilterInitStructure;

  RCC_GetClocksFreq(&RCC_Clocks);

  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 = DISABLE;
  CAN_InitStructure.CAN_RFLM = DISABLE;
  CAN_InitStructure.CAN_TXFP = DISABLE;
  CAN_InitStructure.CAN_Mode = CAN_Mode_Normal ;

  /* quanta 1+14+6 = 21, 21 * 4 = 84, 42000000 / 84 = 5000000 */
  /* CAN Baudrate = 500Kbps (CAN clocked at 42 MHz) Prescale = 4 */

  /* Requires a clock with integer division into APB clock */

  CAN_InitStructure.CAN_SJW = CAN_SJW_1tq; // 1+6+7 = 14, 1+14+6 = 21, 
1+15+5 = 21
  CAN_InitStructure.CAN_BS1 = CAN_BS1_14tq;
  CAN_InitStructure.CAN_BS2 = CAN_BS2_6tq;
  CAN_InitStructure.CAN_Prescaler = 4; // quanta by baudrate - 125kbps

  CAN_Init(CAN2, &CAN_InitStructure);

  /* CAN filter init */
  CAN_FilterInitStructure.CAN_FilterMode = CAN_FilterMode_IdMask; // 
IdMask or IdList
  CAN_FilterInitStructure.CAN_FilterScale = CAN_FilterScale_16bit; // 16 
or 32

  CAN_FilterInitStructure.CAN_FilterIdHigh      = 0x0000; // Everything, 
otherwise 11-bit in top bits
  CAN_FilterInitStructure.CAN_FilterIdLow       = 0x0000;
  CAN_FilterInitStructure.CAN_FilterMaskIdHigh  = 0x0000;
  CAN_FilterInitStructure.CAN_FilterMaskIdLow   = 0x0000;

  CAN_FilterInitStructure.CAN_FilterFIFOAssignment = CAN_FIFO0; // Rx
  CAN_FilterInitStructure.CAN_FilterActivation = ENABLE;

  //CAN_FilterInitStructure.CAN_FilterNumber = 0; // CAN1 [ 0..13]

//  CAN_FilterInit(&CAN_FilterInitStructure);

  CAN_FilterInitStructure.CAN_FilterNumber = 14; // CAN2 [14..27]

  CAN_FilterInit(&CAN_FilterInitStructure);
  CAN_ITConfig(CAN2, CAN_IT_FMP0, ENABLE);

 CanTxMsg TxMessage;

  // transmit */
  TxMessage.StdId = 0x321;
  TxMessage.ExtId = 0x00;
  TxMessage.RTR = CAN_RTR_DATA;
  TxMessage.IDE = CAN_ID_STD;
  TxMessage.DLC = 8;

  TxMessage.Data[0] = 0x02;
  TxMessage.Data[1] = 0x11;
  TxMessage.Data[2] = 0x11;
  TxMessage.Data[3] = 0x11;

 while(1)
  {
    uint32_t i;
     int j = 0;
    uint8_t TransmitMailbox = 0;

  TxMessage.Data[4] = (j >>  0) & 0xFF; // Cycling
   TxMessage.Data[5] = (j >>  8) & 0xFF;
    TxMessage.Data[6] = (j >> 16) & 0xFF;
    TxMessage.Data[7] = (j >> 24) & 0xFF;
    j++;

    TransmitMailbox = CAN_Transmit(CAN2, &TxMessage);

i = 0;
    while((CAN_TransmitStatus(CAN2, TransmitMailbox) != CANTXOK) && (i 
!= 0xFFFF)) // Wait on Transmit
    {
      i++;
      CAN2RX();// Pump RX
    }

  }

}

Answer 1

这是任何CAN总线的默认行为。总线上至少需要两个CAN控制器才能建立通信。如果只有一个节点，除了错误帧，你什么也得不到。

出于调试目的，所有CAN控制器都有一个＆＃34;环回＆＃34;调试功能，允许他们确认和收听自己的帧。如果您独自乘坐公共汽车，则必须启用此功能。

或者，如果在同一个MCU中有两个CAN控制器，则可以启用它们并将它们连接在一起。

Answer 2

可能你应该启用transseiver：它应该在输入端有一些电压（Vbat = 12V）和Vi / o，你还需要启用EN Pin。

CAN BUS确认错误

2 个答案: