AD采集模块，采集到的数据老是有波动，求大神指教

只看该作者 · 2015-4-9 22:45

void ADC3_IN4_Config(void)
{
GPIO_InitTypeDef       GPIO_InitStructure;
DMA_InitTypeDef       DMA_InitStructure;
ADC_InitTypeDef       ADC_InitStructure;
ADC_CommonInitTypeDef ADC_CommonInitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2,  ENABLE);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure);

DMA_InitStructure.DMA_Channel          = DMA_Channel_0;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADC1_DR_Addr;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&ADC1ConvertedValue;
DMA_InitStructure.DMA_DIR             = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_BufferSize       = RTD_RX_NO;
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_PeripheralDataSize_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);

ADC_DeInit();
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_ExternalTrigConv = ADC_ExternalTrigConv_T2_CC2;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfConversion = 1;
ADC_Init(ADC1, &ADC_InitStructure);

ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;
ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div8;
ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled;
ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_20Cycles;
ADC_CommonInit(&ADC_CommonInitStructure);

ADC_RegularChannelConfig(ADC1, ADC_Channel_7, 1, ADC_SampleTime_480Cycles);

ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE);

ADC_DMACmd(ADC1, ENABLE);

ADC_Cmd(ADC1, ENABLE);

ADC_SoftwareStartConv(ADC1);
}