STM32用DMA接收 串口二的信息实现代码库函数实现方式

以下是使用DMA接收串口二数据的代码库函数实现方式：

1. 配置串口二接收DMA通道

void USART2_DMA_Init(void)
{
    DMA_InitTypeDef DMA_InitStructure;

    /* 开启DMA时钟 */
    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);

    /* 复位DMA1通道6 */
    DMA_DeInit(DMA1_Channel6);

    /* 配置DMA1通道6 */
    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&USART2->DR;
    DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)USART2_RxBuffer;
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
    DMA_InitStructure.DMA_BufferSize = USART2_RX_BUFFER_SIZE;
    DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
    DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
    DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
    DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
    DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
    DMA_InitStructure.DMA_Priority = DMA_Priority_High;
    DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
    DMA_Init(DMA1_Channel6, &DMA_InitStructure);

    /* 开启DMA1通道6 */
    DMA_Cmd(DMA1_Channel6, ENABLE);
}

2. 配置串口二接收中断

void USART2_IRQ_Init(void)
{
    NVIC_InitTypeDef NVIC_InitStructure;

    /* 使能串口二接收中断 */
    USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);

    /* 配置串口二接收中断优先级 */
    NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);
}

3. 在USART2_IRQHandler中处理中断

void USART2_IRQHandler(void)
{
    if (USART_GetITStatus(USART2, USART_IT_RXNE) != RESET)
    {
        /* 清除中断标志位 */
        USART_ClearITPendingBit(USART2, USART_IT_RXNE);

        /* 处理接收到的数据 */
        USART2_RxBuffer[USART2_RxCounter++] = USART_ReceiveData(USART2);

        /* 判断是否超出接收缓冲区大小，超出则重新开始接收 */
        if (USART2_RxCounter == USART2_RX_BUFFER_SIZE)
        {
            USART2_RxCounter = 0;
        }
    }
}

4. 在Main函数中初始化串口二、DMA和中断

int main(void)
{
    /* 初始化串口二 */
    USART2_Init();

    /* 初始化DMA */
    USART2_DMA_Init();

    /* 初始化中断 */
    USART2_IRQ_Init();

    while (1)
    {
        /* do something */
    }
}

以上代码实现了使用DMA接收串口二数据，并通过中断处理函数将数据存储到缓冲区中。在主程序中可以根据需要读取缓冲区中的数据。