AD配置
    GPIO_StructInit(&GPIO_InitStructure);
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1| GPIO_Pin_2 | GPIO_Pin_4 ;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);


    DMA_DeInit(DMA1_Channel1);
    DMA_StructInit(&DMA_InitStructure);
    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&ADC1->DR;
    DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)AD_Value;
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
    DMA_InitStructure.DMA_BufferSize = CNL * NOFCHANEL;
    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);


    ADC_DeInit(ADC1);
    ADC_StructInit(&ADC_InitStructure);
    ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
    ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
    ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
    ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConvEdge_None;
    ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
    ADC_InitStructure.ADC_ScanDirection = ADC_ScanDirection_Upward;
    ADC_Init(ADC1, &ADC_InitStructure);


    RCC_ADCCLKConfig(RCC_ADCCLK_PCLK_Div4);

    ADC_ChannelConfig(ADC1, ADC_Channel_0 , ADC_SampleTime_239_5Cycles);
    ADC_ChannelConfig(ADC1, ADC_Channel_1 , ADC_SampleTime_239_5Cycles);
    ADC_ChannelConfig(ADC1, ADC_Channel_2 , ADC_SampleTime_239_5Cycles);
    ADC_ChannelConfig(ADC1, ADC_Channel_4 , ADC_SampleTime_239_5Cycles);

    ADC_GetCalibrationFactor(ADC1);
    ADC_DMARequestModeConfig(ADC1, ADC_DMAMode_Circular);//开启循环模式


    DMA_Cmd(DMA1_Channel1, ENABLE);
    DMA_ITConfig(DMA1_Channel1, DMA_IT_TC, ENABLE);
    ADC_DMACmd(ADC1, ENABLE);  
    ADC_Cmd(ADC1, ENABLE);     

    while(ADC_GetFlagStatus(ADC1,ADC_FLAG_ADEN) == RESET);

    ADC_StartOfConversion(ADC1);