STM32F103C8T6的CAN通信调试问题

只看该作者 · 2016-4-12 20:44

CAN通信调试好几天了，被一个问题卡住，用到是3.5的库，发送函数先贴出代码
uint8_t CAN_Transmit(CAN_TypeDef* CANx, CanTxMsg* TxMessage)
{
  uint8_t transmit_mailbox = 0;
  /* Check the parameters */
  assert_param(IS_CAN_ALL_PERIPH(CANx));
  assert_param(IS_CAN_IDTYPE(TxMessage->IDE));
  assert_param(IS_CAN_RTR(TxMessage->RTR));
  assert_param(IS_CAN_DLC(TxMessage->DLC));

  /* Select one empty transmit mailbox */
  if ((CANx->TSR&CAN_TSR_TME0) == CAN_TSR_TME0)
  {
transmit_mailbox = 0;
  }
  else if ((CANx->TSR&CAN_TSR_TME1) == CAN_TSR_TME1)
  {
transmit_mailbox = 1;
  }
  else if ((CANx->TSR&CAN_TSR_TME2) == CAN_TSR_TME2)
  {
transmit_mailbox = 2;
  }
  else
  {
transmit_mailbox = CAN_TxStatus_NoMailBox;
  }

  if (transmit_mailbox != CAN_TxStatus_NoMailBox)
  {
/* Set up the Id */
CANx->sTxMailBox[transmit_mailbox].TIR &= TMIDxR_TXRQ;
if (TxMessage->IDE == CAN_Id_Standard)
{
   assert_param(IS_CAN_STDID(TxMessage->StdId));
   CANx->sTxMailBox[transmit_mailbox].TIR |= ((TxMessage->StdId << 21) | \
                                                TxMessage->RTR);
}
else
{
   assert_param(IS_CAN_EXTID(TxMessage->ExtId));
   CANx->sTxMailBox[transmit_mailbox].TIR |= ((TxMessage->ExtId << 3) | \
                                                TxMessage->IDE | \
                                                TxMessage->RTR);
}

/* Set up the DLC */
TxMessage->DLC &= (uint8_t)0x0000000F;
CANx->sTxMailBox[transmit_mailbox].TDTR &= (uint32_t)0xFFFFFFF0;
CANx->sTxMailBox[transmit_mailbox].TDTR |= TxMessage->DLC;

/* Set up the data field */
CANx->sTxMailBox[transmit_mailbox].TDLR = (((uint32_t)TxMessage->Data[3] << 24) |
                                          ((uint32_t)TxMessage->Data[2] << 16) |
                                          ((uint32_t)TxMessage->Data[1] << 8) |
                                          ((uint32_t)TxMessage->Data[0]));
CANx->sTxMailBox[transmit_mailbox].TDHR = (((uint32_t)TxMessage->Data[7] << 24) |
                                          ((uint32_t)TxMessage->Data[6] << 16) |
                                          ((uint32_t)TxMessage->Data[5] << 8) |
                                          ((uint32_t)TxMessage->Data[4]));
/* Request transmission */
CANx->sTxMailBox[transmit_mailbox].TIR |= TMIDxR_TXRQ;
  }
  return transmit_mailbox;
}

分别查询空闲发送信箱后，transmit_mailbox最后为4，导致后续无法继续发送，是因为发送完成过后缺少清空信箱的操作导致最后没有空闲信箱吗？
在transmit_mailbox为0,1,2,4时读取CAN_TSR寄存器的值分别是0x1c000000,0x19000008,0x52000008,0x82000008，一直提示TERR0=1，邮箱0因为出错导致发送失败
不知道是什么原因