GD32f103能通过DMA接收串口数据然后通过DAC输出嘛

当然可以，GD32F103微控制器支持DMA（直接内存访问）功能，这对于高性能的数据传输非常有用，包括从串口接收数据并通过DAC输出。以下是一个基本步骤说明如何实现这一过程：

1. **初始化硬件**:
- 初始化串口(Serial Port)和DMA通道，例如USART1和DMA1 Channel 5:

     USART_InitTypeDef usartInit;
     DMA_HandleTypeDef dmaHandle;

     usartInit.USART_BaudRate = YOUR_BAUD_RATE;
     usartInit.USART_WordLength = USART_WordLength_8b;
     //... 其他串口配置...
     USART_Init(USART1, &usartInit);
     USART_Cmd(USART1, ENABLE);
     
     dmaHandle.Init.Channel = DMA_CHANNEL_5;
     dmaHandle.Init.Direction = DMA_PERIPH_TO_MEMORY;
     dmaHandle.Init.PeriphInc = DMA_PeripheralInc_Disable;
     dmaHandle.Init.MemInc = DMA_MemoryInc_Enable;
     dmaHandle.Init.PeriphDataAlignment = DMA_PeripheralDataAlignment_Right;
     dmaHandle.Init.MemDataAlignment = DMA_MemoryDataAlignment_Word;
     dmaHandle.Init.Mode = DMA_Mode_Circular;
     dmaHandle.Init.Priority = DMA_PRIORITY_High;
     dmaHandle.Init.FIFOMode = DMA_FIFOMode Disabled;
     HAL_DMA_Init(&dmaHandle);

2. **配置串口接收事件**:
- 注册DMA回调函数以便在串口接收到数据时启动DMA:

     void USART1_IRQHandler(void) {
         if(HAL_UART_GetFlagStatus(USART1, USART_FLAG_RXNE)) {
             HAL_UART_IRQHandler(USART1);
             HAL_DMA_Start_IT(&dmaHandle, USART1.periphBase, (uint32_t)&USART1.RxData, sizeof(uint8_t));
         }
     }

     HAL_NVIC_EnableIRQ(USART1_IRQn);

3. **设置DAC**:
- 初始化DAC并配置好输出通道，例如DAC1 Channel 1:

     dacInit.ChannelConfStructure.DAC_Trigger = DAC_Trigger_None;
     dacInit.ChannelConfStructure.DAC_OutputBuffer = DAC_OutputBuffer_Enable;
     dacInit.ChannelConfStructure.DAC_Mode = DAC_Mode_Clock;
     dacInit.ChannelConfStructure.DAC_SampleAndHold = DAC_SampleAndHold_Off;
     dacInit.ChannelConfStructure.DAC_Prescaler = DAC_Prescaler_Div2;
     dacInit.ChannelConfStructure.DAC_DMAAccessMode = DAC_DMAAccessMode_Disabled;
     dac_Init(DAC1, &dacChannel1Config);

4. **开始DMA传输**:
- 当串口接收数据后，DMA将数据传输到指定的内存区域，然后你可以从那里获取数据并将其写入DAC:

   while (!DMA_IsTransferCompleted(&dmaHandle)) {}
   uint8_t receivedByte = USART1.RxData;
   DAC_SetData(DAC1, DAC_CHANNEL_1, receivedByte << 8); // 数据左移后写入DAC

记得根据实际情况调整参数和配置，并且在生产环境中加入错误处理和日志记录。