STM32CubeMX：UART操作

只看该作者 · 2021-7-7 09:16

UART共有三种操作方式，轮询方式、中断方式以及DMA方式。

芯片：STM32F103C8T6

应用管脚：

输出：PA0、PA1

USART1

配置界面

添加中断配置

添加DMA配置

只看该作者 · 2021-7-7 09:18

代码应用

1.实现printf函数

/* USER CODE BEGIN 0 */
#ifdef __GNUC__
/* With GCC/RAISONANCE, small printf (option LD Linker->Libraries->Small printf
set to 'Yes') calls __io_putchar() */
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else
#define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif /* __GNUC__ */
/* USER CODE END 0 */

/* USER CODE BEGIN 4 */
/**
  * @brief  Retargets the C library printf function to the USART.
  * @param  None
  * @retval None
  */
PUTCHAR_PROTOTYPE
{
  /* Place your implementation of fputc here */
  /* e.g. write a character to the USART1 and Loop until the end of transmission */
  HAL_UART_Transmit(&huart1, (uint8_t *)&ch, 1, 0xFFFF);
  return ch;
}
/* USER CODE END 4 */
2.轮询方式发送与接收

发送数据

</pre><pre name="code" class="cpp">uint8_t senddata[20]="This use Transmit.\r\n";
if(HAL_UART_Transmit(&huart1,senddata,sizeof(senddata),0xFFFF) != HAL_OK)
  {
/* Transfer error in reception process */
Error_Handler();
  }
轮询接收采用阻塞式超时接收模式

  uint8_t huart1_RxBuffer[20];
  HAL_UART_Receive(&huart1, huart1_RxBuffer, 20,0x10);

只看该作者 · 2021-7-7 09:18

3.中断方式发送与接收
增加接收中断回调函数

/* USER CODE BEGIN 4 */
/**
  * @brief  Rx 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_RxCpltCallback(UART_HandleTypeDef *huart)
{
if(huart==&huart1)
{
Rx_flag=1;
HAL_GPIO_WritePin(GPIOA,GPIO_PIN_0,(GPIO_PinState)!HAL_GPIO_ReadPin(GPIOA,GPIO_PIN_0));

// if(HAL_UART_Receive_IT(&huart1, (uint8_t *)huart1_RxBuffer, Rx_size) != HAL_OK)
// {
// /* Transfer error in reception process */
// Error_Handler();
// }
}
}

/* USER CODE END 4 */
发送数据
uint8_t senddata_IT[23]="This use Transmit IT.\r\n";
if(HAL_UART_Transmit_IT(&huart1,senddata_IT, sizeof(senddata_IT)) != HAL_OK)
{
/* Transfer error in reception process */
Error_Handler();
}
接收数据，调用此函数后，接收中断可执行一次。
<pre name="code" class="cpp">uint8_t huart1_RxBuffer[20];
if(HAL_UART_Transmit_DMA(&huart1,senddata_DMA, sizeof(senddata_DMA))!= HAL_OK)
{
Error_Handler();
}

if(HAL_UART_Receive_IT(&huart1, (uint8_t *)huart1_RxBuffer, Rx_size) != HAL_OK) {/* Transfer error in reception process */ Error_Handler(); }
3.DMA方式发送与接收
增加接收中断回调函数（与中断方式相同）

发送数据

uint8_t senddata_DMA[24]="This use Transmit DMA.\r\n";
if(HAL_UART_Receive_DMA(&huart1, (uint8_t *)huart1_RxBuffer, Rx_size) != HAL_OK)
  {
/* Transfer error in reception process */
Error_Handler();
  }

接收数据（特征与中断方式相同）
if(HAL_UART_Receive_DMA(&huart1, (uint8_t *)huart1_RxBuffer, Rx_size) != HAL_OK)
  {
/* Transfer error in reception process */
Error_Handler();
  }