F411DMA方式4通道AD的C问题

me浩提问时间：2015-7-29 10:39 /

代码如下，为什么采集回来只有两个数据而且跳变很大？求指导。
void Adc_DMA_Init(void)
{
//----------------------------初始化DMA----------------------------//
      GPIO_InitTypeDef GPIO_InitStructure;
      ADC_InitTypeDef  ADC_InitStructure;
      ADC_CommonInitTypeDef ADC_CommonInitStructure;
      DMA_InitTypeDef  DMA_InitStructure;

      RCC_AHB1PeriphClockCmd( RCC_AHB1Periph_DMA2 |
                                                      RCC_AHB1Periph_GPIOA|
                                                      RCC_AHB1Periph_GPIOC, ENABLE);
      RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE); //使能ADC1时钟

      DMA_InitStructure.DMA_Channel = DMA_Channel_0;  //通道选择
      DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADC1_DR_Address;//(uint32_t)&ADC1->DR
      DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&AD;
      DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
      DMA_InitStructure.DMA_BufferSize = 4;
      DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;//外设地址不变
      DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;//内存地址递增
      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_FIFOMode = DMA_FIFOMode_Disable;
      DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;
      DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
      DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
      DMA_Init(DMA2_Stream0,&DMA_InitStructure);
      DMA_Cmd(DMA2_Stream0,ENABLE);

      //先初始化ADC1通道1,4 IO口
      GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1 | GPIO_Pin_4;//PA1 通道1,PA4 通道4
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;//模拟输入
      GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;//不带上下拉
      GPIO_Init(GPIOA, &GPIO_InitStructure);//初始化
      //先初始化ADC1通道10,11 IO口
      GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1;//PC0 通道10,PC1 通道11
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;//模拟输入
      GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;//不带上下拉
      GPIO_Init(GPIOC, &GPIO_InitStructure);//初始化

//----------------------------初始化ADC----------------------------//
      ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;//独立模式
      ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles;//两个采样阶段之间的延迟5个时钟
      ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_1; //DMA失能
      ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div8;//预分频4分频。ADCCLK=PCLK2/4=84/4=21Mhz,ADC时钟最好不要超过36Mhz
      ADC_CommonInit(&ADC_CommonInitStructure);//初始化

      ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;//12位模式
      ADC_InitStructure.ADC_ScanConvMode = ENABLE;//扫描模式
      ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;//连续转换
      ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;//禁止触发检测，使用软件触发
      ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;//右对齐
      ADC_InitStructure.ADC_NbrOfConversion = 4;//1个转换在规则序列中也就是只转换规则序列1
      ADC_Init(ADC1, &ADC_InitStructure);//ADC初始化

      ADC_RegularChannelConfig(ADC1,ADC_Channel_10,1,ADC_SampleTime_15Cycles);
      ADC_RegularChannelConfig(ADC1,ADC_Channel_11,2,ADC_SampleTime_15Cycles);
      ADC_RegularChannelConfig(ADC1,ADC_Channel_1,3,ADC_SampleTime_15Cycles);
      ADC_RegularChannelConfig(ADC1,ADC_Channel_4,4,ADC_SampleTime_15Cycles);

      ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE);
      ADC_DMACmd(ADC1,ENABLE);//使能ADC的DMA传输
      ADC_Cmd(ADC1, ENABLE);//开启AD转换器

      ADC_SoftwareStartConv(ADC1);       //连续转换开始，ADC通过DMA方式不断的更新RAM区。

}