stm32f407串口中断接收

### STM32F407 UART 中断接收实现

对于STM32F407单片机而言，利用中断方式来处理UART数据接收是一种常见且高效的方法。通过配置NVIC (Nested Vectored Interrupt Controller)，可以确保当有新字符到达时触发相应的中断服务程序(ISR)[^1]。

下面是一个简单的例子展示如何设置并启用UART接收中断：

#### 配置USART初始化结构体

static void MX_USART1_UART_Init(void)
{
    huart1.Instance = USART1;
    huart1.Init.BaudRate = 115200;
    huart1.Init.WordLength = UART_WORDLENGTH_8B;
    huart1.Init.StopBits = UART_STOPBITS_1;
    huart1.Init.Parity = UART_PARITY_NONE;
    huart1.Init.Mode = UART_MODE_TX_RX; // Enable both transmit and receive modes.
    huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
    huart1.Init.OverSampling = UART_OVERSAMPLING_16;

    if (HAL_UART_Init(&huart1) != HAL_OK){
        Error_Handler();
    }
}

#### 启用全局中断以及特定外设的中断线
为了使能UART接收完成中断，在`MX_NVIC_Config()`函数里添加如下代码片段:

void MX_NVIC_Config(void)
{
    /* Configure one bit for preemption priority */
    NVIC_SetPriorityGrouping(NVIC_PRIORITYGROUP_4);

    /* Enable the USART1 global interrupt */
    HAL_NVIC_EnableIRQ(USART1_IRQn);
    
    /* Set the USART1 IRQ channel priority level to medium-low */
    HAL_NVIC_SetPriority(USART1_IRQn, 5, 0);  
}

#### 编写ISR处理接收到的数据
定义一个用于存储接收到字节缓冲区，并编写对应的中断服务子程序来填充此缓冲区：

uint8_t rxBuffer[RECEIVE_BUFFER_SIZE];
volatile uint16_t rxIndex = 0;

void USART1_IRQHandler(void)
{
    /* Check whether the received data register not empty flag is set */
    if (__HAL_UART_GET_FLAG(&huart1, UART_FLAG_RXNE)){
        
        /* Read a single byte from the hardware buffer into our software buffer */
        rxBuffer[rxIndex++] = (uint8_t)(huart1.Instance->DR & (uint8_t)0xFF);
        
        /* If we've filled up the entire buffer then reset index back to start */
        if(rxIndex >= RECEIVE_BUFFER_SIZE){
            rxIndex = 0;
        }

        __HAL_UART_CLEAR_IT(&huart1,UART_CLEAR_IDLEF); // Clear IDLE Flag
        
        /* Optionally call another function here that processes incoming bytes */
    }else {
      /* Handle other possible interrupts like overrun error etc.*/
    }
}

上述代码展示了基本框架下的UART接收中断机制。值得注意的是，实际应用中可能还需要考虑更多细节问题，比如错误检测与恢复、多字节消息解析等逻辑。