STM32F4 HAL库的三个发送邮箱处理方法

eric2013

框图：



HAL库的处理，库本身做的处理：

[C] 纯文本查看 复制代码

/**
  * @brief  Add a message to the first free Tx mailbox and activate the
  *         corresponding transmission request.
  * @param  hcan pointer to a CAN_HandleTypeDef structure that contains
  *         the configuration information for the specified CAN.
  * @param  pHeader pointer to a CAN_TxHeaderTypeDef structure.
  * @param  aData array containing the payload of the Tx frame.
  * @param  pTxMailbox pointer to a variable where the function will return
  *         the TxMailbox used to store the Tx message.
  *         This parameter can be a value of @arg CAN_Tx_Mailboxes.
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_CAN_AddTxMessage(CAN_HandleTypeDef *hcan, CAN_TxHeaderTypeDef *pHeader, uint8_t aData[], uint32_t *pTxMailbox)
{
  uint32_t transmitmailbox;
  HAL_CAN_StateTypeDef state = hcan->State;
  uint32_t tsr = READ_REG(hcan->Instance->TSR);

  /* Check the parameters */
  assert_param(IS_CAN_IDTYPE(pHeader->IDE));
  assert_param(IS_CAN_RTR(pHeader->RTR));
  assert_param(IS_CAN_DLC(pHeader->DLC));
  if (pHeader->IDE == CAN_ID_STD)
  {
    assert_param(IS_CAN_STDID(pHeader->StdId));
  }
  else
  {
    assert_param(IS_CAN_EXTID(pHeader->ExtId));
  }
  assert_param(IS_FUNCTIONAL_STATE(pHeader->TransmitGlobalTime));

  if ((state == HAL_CAN_STATE_READY) ||
      (state == HAL_CAN_STATE_LISTENING))
  {
    /* Check that all the Tx mailboxes are not full */
    if (((tsr & CAN_TSR_TME0) != 0U) ||
        ((tsr & CAN_TSR_TME1) != 0U) ||
        ((tsr & CAN_TSR_TME2) != 0U))
    {
      /* Select an empty transmit mailbox */
      transmitmailbox = (tsr & CAN_TSR_CODE) >> CAN_TSR_CODE_Pos;

      /* Check transmit mailbox value */
      if (transmitmailbox > 2U)
      {
        /* Update error code */
        hcan->ErrorCode |= HAL_CAN_ERROR_INTERNAL;

        return HAL_ERROR;
      }

      /* Store the Tx mailbox */
      *pTxMailbox = (uint32_t)1 << transmitmailbox;

      /* Set up the Id */
      if (pHeader->IDE == CAN_ID_STD)
      {
        hcan->Instance->sTxMailBox[transmitmailbox].TIR = ((pHeader->StdId << CAN_TI0R_STID_Pos) |
                                                           pHeader->RTR);
      }
      else
      {
        hcan->Instance->sTxMailBox[transmitmailbox].TIR = ((pHeader->ExtId << CAN_TI0R_EXID_Pos) |
                                                           pHeader->IDE |
                                                           pHeader->RTR);
      }

      /* Set up the DLC */
      hcan->Instance->sTxMailBox[transmitmailbox].TDTR = (pHeader->DLC);

      /* Set up the Transmit Global Time mode */
      if (pHeader->TransmitGlobalTime == ENABLE)
      {
        SET_BIT(hcan->Instance->sTxMailBox[transmitmailbox].TDTR, CAN_TDT0R_TGT);
      }

      /* Set up the data field */
      WRITE_REG(hcan->Instance->sTxMailBox[transmitmailbox].TDHR,
                ((uint32_t)aData[7] << CAN_TDH0R_DATA7_Pos) |
                ((uint32_t)aData[6] << CAN_TDH0R_DATA6_Pos) |
                ((uint32_t)aData[5] << CAN_TDH0R_DATA5_Pos) |
                ((uint32_t)aData[4] << CAN_TDH0R_DATA4_Pos));
      WRITE_REG(hcan->Instance->sTxMailBox[transmitmailbox].TDLR,
                ((uint32_t)aData[3] << CAN_TDL0R_DATA3_Pos) |
                ((uint32_t)aData[2] << CAN_TDL0R_DATA2_Pos) |
                ((uint32_t)aData[1] << CAN_TDL0R_DATA1_Pos) |
                ((uint32_t)aData[0] << CAN_TDL0R_DATA0_Pos));

      /* Request transmission */
      SET_BIT(hcan->Instance->sTxMailBox[transmitmailbox].TIR, CAN_TI0R_TXRQ);

      /* Return function status */
      return HAL_OK;
    }
    else
    {
      /* Update error code */
      hcan->ErrorCode |= HAL_CAN_ERROR_PARAM;

      return HAL_ERROR;
    }
  }
  else
  {
    /* Update error code */
    hcan->ErrorCode |= HAL_CAN_ERROR_NOT_INITIALIZED;

    return HAL_ERROR;
  }
}

Y1ng

这一段代码怎么用？

eric2013

Y1ng 发表于 2024-1-14 19:26
这一段代码怎么用？

直接调用就行，HAL库的这个API自动从里面选择选择可用的发送邮箱了。

基于STM32F429的HAL版双CAN通信案例（2023-10-24）
https://www.armbbs.cn/forum.php? ... 1523&fromuid=58
(出处: 硬汉嵌入式论坛)