使用stm32cubemx开发四：串口标准化输出

硬件平台：stm32F407Zet6

软件平台：stm32cubeMX 4.7+MDK5.14

电路连接：PA9,PA10

第一步、通过Stm32CubeMX图形界面创建Keil工程

需要配置的地方是

在这里可以修改串口工作的一下参数，软件就可以生成配置好的工程，不需要亲自去配置这些了。

第二步。打开工程，编写代码，验证

/* USER CODE BEGIN PV */
#include "stdio.h"
#ifdef __GNUC__
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else
#define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif /* __GNUC__ */
PUTCHAR_PROTOTYPE
{
	HAL_UART_Transmit(&huart1 , (uint8_t *)&ch, 1, 0xFFFF);
	return ch;
}
/* USER CODE END PV */

这段程序为了可以使用printf（）函数，对字符输出函数进行了重定向，这样我们就可以在程序中使用printf函数进行输出了，这里使用的是查询发送方式，有超时控制的。接下来来看中断方式的。

/**
  * @brief  This function handles UART interrupt request.
  * @param  huart: pointer to a UART_HandleTypeDef structure that contains
  *                the configuration information for the specified UART module.
  * @retval None
  */
void HAL_UART_IRQHandler(UART_HandleTypeDef *huart)
{
  uint32_t tmp1 = 0, tmp2 = 0;

  tmp1 = __HAL_UART_GET_FLAG(huart, UART_FLAG_PE);
  tmp2 = __HAL_UART_GET_IT_SOURCE(huart, UART_IT_PE);  
  /* UART parity error interrupt occurred ------------------------------------*/
  if((tmp1 != RESET) && (tmp2 != RESET))
  { 
    __HAL_UART_CLEAR_PEFLAG(huart);
    
    huart->ErrorCode |= HAL_UART_ERROR_PE;
  }
  
  tmp1 = __HAL_UART_GET_FLAG(huart, UART_FLAG_FE);
  tmp2 = __HAL_UART_GET_IT_SOURCE(huart, UART_IT_ERR);
  /* UART frame error interrupt occurred -------------------------------------*/
  if((tmp1 != RESET) && (tmp2 != RESET))
  { 
    __HAL_UART_CLEAR_FEFLAG(huart);
    
    huart->ErrorCode |= HAL_UART_ERROR_FE;
  }
  
  tmp1 = __HAL_UART_GET_FLAG(huart, UART_FLAG_NE);
  tmp2 = __HAL_UART_GET_IT_SOURCE(huart, UART_IT_ERR);
  /* UART noise error interrupt occurred -------------------------------------*/
  if((tmp1 != RESET) && (tmp2 != RESET))
  { 
    __HAL_UART_CLEAR_NEFLAG(huart);
    
    huart->ErrorCode |= HAL_UART_ERROR_NE;
  }
  
  tmp1 = __HAL_UART_GET_FLAG(huart, UART_FLAG_ORE);
  tmp2 = __HAL_UART_GET_IT_SOURCE(huart, UART_IT_ERR);
  /* UART Over-Run interrupt occurred ----------------------------------------*/
  if((tmp1 != RESET) && (tmp2 != RESET))
  { 
    __HAL_UART_CLEAR_OREFLAG(huart);
    
    huart->ErrorCode |= HAL_UART_ERROR_ORE;
  }
  
  tmp1 = __HAL_UART_GET_FLAG(huart, UART_FLAG_RXNE);
  tmp2 = __HAL_UART_GET_IT_SOURCE(huart, UART_IT_RXNE);
  /* UART in mode Receiver ---------------------------------------------------*/
  if((tmp1 != RESET) && (tmp2 != RESET))
  { 
    UART_Receive_IT(huart);
  }
  
  tmp1 = __HAL_UART_GET_FLAG(huart, UART_FLAG_TXE);
  tmp2 = __HAL_UART_GET_IT_SOURCE(huart, UART_IT_TXE);
  /* UART in mode Transmitter ------------------------------------------------*/
  if((tmp1 != RESET) && (tmp2 != RESET))
  {
    UART_Transmit_IT(huart);
  }
  
  tmp1 = __HAL_UART_GET_FLAG(huart, UART_FLAG_TC);
  tmp2 = __HAL_UART_GET_IT_SOURCE(huart, UART_IT_TC);
  /* UART in mode Transmitter end --------------------------------------------*/
  if((tmp1 != RESET) && (tmp2 != RESET))
  {
    UART_EndTransmit_IT(huart);
  }

  if(huart->ErrorCode != HAL_UART_ERROR_NONE)
  {
    /* Set the UART state ready to be able to start again the process */
    huart->State = HAL_UART_STATE_READY;
    
    HAL_UART_ErrorCallback(huart);
  }  
}

这个函数中查询了所有可能发生的中断。用到的中断是发送完成中断，就找到了UART_EndTransmit_IT(huart);再跳进去看看，

/**
  * @brief  Wraps up transmission in non blocking mode.
  * @param  huart: pointer to a UART_HandleTypeDef structure that contains
  *                the configuration information for the specified UART module.
  * @retval HAL status
  */
static HAL_StatusTypeDef UART_EndTransmit_IT(UART_HandleTypeDef *huart)
{
  /* Disable the UART Transmit Complete Interrupt */    
  __HAL_UART_DISABLE_IT(huart, UART_IT_TC);
  
  /* Check if a receive process is ongoing or not */
  if(huart->State == HAL_UART_STATE_BUSY_TX_RX) 
  {
    huart->State = HAL_UART_STATE_BUSY_RX;
  }
  else
  {
    /* Disable the UART Parity Error Interrupt */
    __HAL_UART_DISABLE_IT(huart, UART_IT_PE);

    /* Disable the UART Error Interrupt: (Frame error, noise error, overrun error) */
    __HAL_UART_DISABLE_IT(huart, UART_IT_ERR);

    huart->State = HAL_UART_STATE_READY;
  }
  
  HAL_UART_TxCpltCallback(huart);
  
  return HAL_OK;
}

这个函数在确定中断发生了之后调用了，HAL_UART_TxCpltCallback(huart);从函数名上可以看出，这是个回调函数，就是留给上层来实现的函数，由这个函数的实现不同，来实现不同的功能。这里来实现这个函数，让它在中断发生的时候吧USART1Ready置为SET；代码修改如下

/* USER CODE BEGIN PV */
#include "stdio.h"
#ifdef __GNUC__
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else
#define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif /* __GNUC__ */
__IO ITStatus USART1Ready = RESET;

PUTCHAR_PROTOTYPE
{
	HAL_UART_Transmit_IT(&huart1 , (uint8_t *)&ch, 1);
	while (USART1Ready != SET)
  {
  }
	USART1Ready = RESET;
	return ch;
}


/* USER CODE END PV */

这是重定向函数的修改，启动发送之后，等待发送完成。重新实现的回调函数如下图所示：

/**
  * @brief  Tx Transfer completed callbacks.
  * @param  huart: pointer to a UART_HandleTypeDef structure that contains
  *                the configuration information for the specified UART module.
  * @retval None
  */
void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart)
{
  /* NOTE: This function Should not be modified, when the callback is needed,
           the HAL_UART_TxCpltCallback could be implemented in the user file
   */ 
	USART1Ready = SET;
}

这样就可以了，下载验证。