stm32f103串口1DMA初始化怎么写？

下面是stm32f103串口1DMA初始化的代码示例，仅供参考：

// 使能DMA1时钟
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);

// 初始化DMA1通道4，用于USART1的发送
DMA_InitTypeDef DMA_InitStructure;
DMA_DeInit(DMA1_Channel4);
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&USART1->DR;
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)txBuffer;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
DMA_InitStructure.DMA_BufferSize = txBufferSize;
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_M2M = DMA_M2M_Disable;
DMA_Init(DMA1_Channel4, &DMA_InitStructure);

// 初始化USART1
USART_InitTypeDef USART_InitStructure;
USART_InitStructure.USART_BaudRate = 115200;
USART_InitStructure.USART_WordLength = USART_WordLength_8b;
USART_InitStructure.USART_StopBits = USART_StopBits_1;
USART_InitStructure.USART_Parity = USART_Parity_No;
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_InitStructure.USART_Mode = USART_Mode_Tx;
USART_Init(USART1, &USART_InitStructure);

// 使能USART1和DMA1通道4
USART_DMACmd(USART1, USART_DMAReq_Tx, ENABLE);
DMA_Cmd(DMA1_Channel4, ENABLE);
USART_Cmd(USART1, ENABLE);

上述代码中，我们使用DMA1的通道4来实现USART1的发送功能。首先，我们需要初始化DMA1通道4，然后再初始化USART1。在初始化USART1时，我们需要使能USART1的DMA发送请求，并在初始化DMA1通道4后使能该通道和USART1。最后，当需要发送数据时，我们只需要将数据写入txBuffer，并将需要发送的字节数写入txBufferSize，然后触发DMA1通道4的传输即可。