1 void _UART2_Configuration(void)

 2 {

 3   USART_InitTypeDef USART_InitStructure;

 4

 5   USART_OverSampling8Cmd(USART2, ENABLE);

 6   USART_InitStructure.USART_BaudRate = 19200;

 7   USART_InitStructure.USART_WordLength = USART_WordLength_8b;

 8   USART_InitStructure.USART_StopBits = USART_StopBits_1;

 9   USART_InitStructure.USART_Parity = USART_Parity_No;

10   USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;

11   USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;

12   USART_Init(USART2, &USART_InitStructure);

13

14   USART_DMACmd(USART2, USART_DMAReq_Rx, ENABLE);

15

16   DMA_Cmd(DMA1_Stream5, ENABLE);

17

18   USART_Cmd(USART2, ENABLE);

19 }

20

21 void _DMA_Configuration(void)

22 {

23   DMA_InitTypeDef DMA_InitStructure;

24 　DMA_InitStructure.DMA_Channel = DMA_Channel_4;

25   DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&(USART2->DR);

26   DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)_Compass_Value;

27   DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;

28   DMA_InitStructure.DMA_BufferSize = 3;

29   DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;

30   DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;

31   DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;

32   DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;

33   DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;

34   DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;

35   DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;

36   DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;

37   DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;

38   DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;

39   DMA_Init(DMA1_Stream5, &DMA_InitStructure);

40

41   /* DMA2_Stream0 enable */

42   DMA_Cmd(DMA1_Stream5, ENABLE);

43 }