STM32 串口1通过DMA发送数据实现

要实现STM32串口1通过DMA发送数据，需要按照以下步骤进行配置：

1. 选择需要发送的串口，并开启DMA传输功能：

    USART1->CR3 |= USART_CR3_DMAT;

2. 配置DMA传输通道：

    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);
    DMA_InitTypeDef DMA_InitStructure;
    DMA_DeInit(DMA2_Stream7);
    DMA_InitStructure.DMA_Channel = DMA_Channel_4;
    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&USART1->DR;
    DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)send_buf;
    DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral;
    DMA_InitStructure.DMA_BufferSize = send_len;
    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_Normal;
    DMA_InitStructure.DMA_Priority = DMA_Priority_High;
    DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;
    DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;
    DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
    DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
    DMA_Init(DMA2_Stream7, &DMA_InitStructure);

其中，send_buf为待发送的数据缓存，send_len为待发送的数据长度。

3. 启动DMA传输：

    DMA_Cmd(DMA2_Stream7, ENABLE);

4. 等待DMA传输完成：

    while(DMA_GetFlagStatus(DMA2_Stream7,DMA_FLAG_TCIF7)==RESET);
    DMA_ClearFlag(DMA2_Stream7,DMA_FLAG_TCIF7);

5. 关闭DMA传输：

    DMA_Cmd(DMA2_Stream7, DISABLE);

以上就是通过DMA实现STM32串口1发送数据的步骤。需要注意的是，具体的配置参数需要根据情况进行调整。