STM32F205 ADC数据读取值很小 几乎为零的问题

杨腾

按照例程配置的STM32F205的ADC，可正常运行，就是读取数据不对，测的是1.5V左右的电压，串口打印出来只有0点几，几乎为零。而且ADC寄存器的值也很小，

求助大神，这是哪里出问题了，源代码如下

__IO uint16_t ADC_ConvertedValue;
void ADC1_CH6_DMA_Config(void)
{
  ADC_InitTypeDef       ADC_InitStructure;
  ADC_CommonInitTypeDef ADC_CommonInitStructure;
  DMA_InitTypeDef       DMA_InitStructure;
  GPIO_InitTypeDef      GPIO_InitStructure;
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2 | RCC_AHB1Periph_GPIOA, ENABLE);
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);
DMA_DeInit(DMA2_Stream0);
  DMA_InitStructure.DMA_Channel = DMA_Channel_0;  //Ñ¡ÔñDMAͨµÀ
  DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADC1_DR_Address; //ADCµÄÊý¾Ý¼Ä´æÆ÷µØÖ·
  DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&ADC_ConvertedValue; //DMA°ÑÊý¾Ý´æÈëÕâ¸öÊý×飬һ¸ö´æ·ÅADCÖµ£¬Ò»¸ö´æ·ÅζÈÖµ
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;//ÍâÉè´æ´¢µ½ÄÚ´æ
  DMA_InitStructure.DMA_BufferSize = 1; //DMA´æ´¢Êý¾ÝÇø´óС£¬2¸öµ¥Î»
  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;//ÍâÉèµØÖ·²»ÀÛ¼Ó£¬´ÓADC¹Ì¶¨µÄDR¼Ä´æÆ÷È¡Êý¾Ý²»ÐèÒªÀÛ¼ÓµØÖ·
  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Disable;//ÄÚ´æµØÖ·ÀÛ¼Ó
  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;//°ë×Ö
  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
  DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;//DMAÑ­»·Ä£Ê½
  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);
  /* Configure ADC1 Channel6 pin as analog input ******************************/
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;
  GPIO_Init(GPIOA, &GPIO_InitStructure);
  /* ADC Common Init **********************************************************/
  ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;
  ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div2;
  ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled;
  ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles;
  ADC_CommonInit(&ADC_CommonInitStructure);
  /* ADC1 Init ****************************************************************/
  ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
  ADC_InitStructure.ADC_ScanConvMode = DISABLE;
  ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
  ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
  ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
  ADC_InitStructure.ADC_NbrOfConversion = 1;
  ADC_Init(ADC1, &ADC_InitStructure);
  

/* ADC1 regular channe6 configuration *************************************/
  ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_3Cycles);
/* Enable DMA request after last transfer (Single-ADC mode) */
  ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE);
  /* Enable ADC3 DMA */
  ADC_DMACmd(ADC1, ENABLE);
  /* Enable ADC3 */
  ADC_Cmd(ADC1, ENABLE);

  
}
void ADC_Initializes(void)
{
ADC1_CH6_DMA_Config();
ADC_SoftwareStartConv(ADC1);
}

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