STM32F103RCT6的HAL库串口2接收

1. 首先在CubeMX中配置串口2的时钟和GPIO引脚。

2. 在main.c中添加以下代码初始化串口2：

/* USART2 init function */
static void MX_USART2_UART_Init(void)
{
  huart2.Instance = USART2;
  huart2.Init.BaudRate = 115200;
  huart2.Init.WordLength = UART_WORDLENGTH_8B;
  huart2.Init.StopBits = UART_STOPBITS_1;
  huart2.Init.Parity = UART_PARITY_NONE;
  huart2.Init.Mode = UART_MODE_TX_RX;
  huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart2.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart2) != HAL_OK)
  {
    Error_Handler();
  }
}

3. 在main函数中调用MX_USART2_UART_Init()函数进行初始化。

4. 在main函数中添加以下代码实现串口2的中断接收：

/* USER CODE BEGIN 4 */
uint8_t aRxBuffer[RXBUFFERSIZE];//定义接收缓冲区
uint8_t len = 0;
/* USER CODE END 4 */

/* USER CODE BEGIN USART2_IRQn 0 */

/* USER CODE END USART2_IRQn 0 */

/* USER CODE BEGIN USART2_IRQn 1 */

/* USER CODE END USART2_IRQn 1 */
void USART2_IRQHandler(void)
{
  /* USER CODE BEGIN USART2_IRQn 0 */
  uint32_t isrflags   = READ_REG(huart2.Instance->SR);//获取中断标志
  uint32_t cr1its     = READ_REG(huart2.Instance->CR1);//获取中断使能
  uint32_t cr3its     = READ_REG(huart2.Instance->CR3);
  uint32_t errorflags;

  /* If no error occurs */
  errorflags = (isrflags & (uint32_t)(USART_SR_PE | USART_SR_FE | USART_SR_ORE | USART_SR_NE));
  if (errorflags == RESET)
  {
    /* UART in mode Receiver ---------------------------------------------------*/
    if (((isrflags & USART_SR_RXNE) != RESET) && ((cr1its & USART_CR1_RXNEIE) != RESET))
    {
      /* 读取USART2接收到的数据 */
      aRxBuffer[len++] = (uint8_t)(huart2.Instance->DR & (uint8_t)0xFF);
      if(len == RXBUFFERSIZE)
      {
        len = 0;
      }
    }
  }
  /* USER CODE BEGIN USART2_IRQn 1 */

  /* USER CODE END USART2_IRQn 1 */
}

5. 在main函数中添加以下代码实现读取接收缓冲区中的数据：

/* USER CODE BEGIN WHILE */
while (1)
{
  if(len > 0)
  {
    HAL_UART_Transmit(&huart2, aRxBuffer, len, 1000);//将接收到的数据发送回去
    len = 0;
  }
  /* USER CODE END WHILE */

  /* USER CODE BEGIN 3 */

}
/* USER CODE END 3 */