STM32的AD用DMA方式时转换错位

STM32的AD用DMA方式时的请注意初始化顺序
   
    DMA_DeInit(DMA1_Channel1);
    DMA_InitStructure.DMA_PeripheralBaseAddr = ADC1_DR_Address;
    DMA_InitStructure.DMA_MemoryBaseAddr = (u32)&ADC_Result;
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
    DMA_InitStructure.DMA_BufferSize = 6;
    DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
    DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;;
    DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
    DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
    DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
    DMA_InitStructure.DMA_Priority = DMA_Priority_High;
    DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
    DMA_Init(DMA1_Channel1, &DMA_InitStructure);
   
   
    //DMA_Cmd(DMA1_Channel1, ENABLE);//以前在这里启用DMA，出现通道错乱
       
   
    ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
    ADC_InitStructure.ADC_ScanConvMode = ENABLE;
    ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
    ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;
    ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
    ADC_InitStructure.ADC_NbrOfChannel = 6;
    ADC_Init(ADC1, &ADC_InitStructure);

   
    ADC_RegularChannelConfig(ADC1, ADC_Channel_10, 1, ADC_SampleTime_55Cycles5);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_11, 2, ADC_SampleTime_55Cycles5);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_12, 3, ADC_SampleTime_55Cycles5);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_13, 4, ADC_SampleTime_55Cycles5);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_14, 6, ADC_SampleTime_55Cycles5);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_15, 5, ADC_SampleTime_55Cycles5);
   
    ADC_DMACmd(ADC1, ENABLE);
   
   
    ADC_Cmd(ADC1, ENABLE);

       
    ADC_ResetCalibration(ADC1);

  

  while(ADC_GetResetCalibrationStatus(ADC1));

  ADC_StartCalibration(ADC1);

  while(ADC_GetCalibrationStatus(ADC1));

  DMA_Cmd(DMA1_Channel1,ENABLE);

  ADC_SoftwareStartConvCmd(ADC1,ENABLE);



用DMA连续采样多路，自动触发，如果在初始化AD前使能了DMA就会出现数据错位现象。

要注意在初始化时将DMA_Cmd(DMA1_Channel1,ENABLE);放置ADC_SoftwareStartConvCmd(ADC1, ENABLE);前面。
原因是：如果在初始化AD的时候DMA被触发了一次，但是此时并没有采样，但是DMA目的地址已经发生了自加，当你采样第一路的时候，数据却填充到了第二路。
校准AD的时候会触发DMA导致通道错位，因此校准AD基准前不要启用DMA。