前言：

最近在除錯STM32F205晶片ADC多通道DMA方式採集資料，總結下STM32多通道ADC的DMA方式採集的使用方法。

硬體平臺：STM32F205

軟體平臺：keil v5

函式庫：標準庫

多通道ADC的配置

#define Channel_Num  9 //ＡＤＣ的通道數，本例使用9個通道
#define Sample_Num  10 //取樣次數，本例使用平均濾波，取樣10次取均值

u16 ADC_ConvertedValue[Sample_Num][Channel_Num];//ADC採集資料的快取
uint16_t ADC_Value[Channel_Num]={0};//9個ADC通道的取樣值
 

下面為ADC及DMA的詳細配置函式。

void ADC_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 | RCC_AHB1Periph_GPIOC, ENABLE);
 

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);

  DMA_InitStructure.DMA_Channel = DMA_Channel_0;  
  DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&ADC1->DR;
  DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&ADC_ConvertedValue;  
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
 

  DMA_InitStructure.DMA_BufferSize = Sample_Num*Channel_Num;         
  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_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);


  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 |GPIO_Pin_2 | GPIO_Pin_4 | GPIO_Pin_5 | GPIO_Pin_7;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1 | GPIO_Pin_3 | GPIO_Pin_5;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;
  GPIO_Init(GPIOC, &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);

  ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
  ADC_InitStructure.ADC_ScanConvMode = ENABLE;
  ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
  ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
  ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
  ADC_InitStructure.ADC_NbrOfConversion = 9;
  ADC_Init(ADC1, &ADC_InitStructure);


    ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_3Cycles);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 2, ADC_SampleTime_3Cycles);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 3, ADC_SampleTime_3Cycles);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_4, 4, ADC_SampleTime_3Cycles);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_5, 5, ADC_SampleTime_3Cycles);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_7, 6, ADC_SampleTime_3Cycles);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_11, 7, ADC_SampleTime_3Cycles);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_13, 8, ADC_SampleTime_3Cycles);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_15, 9, ADC_SampleTime_3Cycles);


  ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE);

  /* Enable ADC1 DMA */
  ADC_DMACmd(ADC1, ENABLE);

  /* Enable ADC1 */
  ADC_Cmd(ADC1, ENABLE);

}

注意上述配置中 DMA_InitStructure.DMA_BufferSize 應配置為Sample_Num*Channel_Num，而不是通道數。

下面是均值濾波函式。

u16 ReadADCAverageValue(uint16_t Channel)
{
    uint8_t i;
    uint32_t sum = 0;
    for(i=0; i<Sample_Num; i++)
    {
     sum+=ADC_ConvertedValue[i][Channel];
    }
    return (sum/Sample_Num);
}

　　最後，呼叫ADC_SoftwareStartConv(ADC1)函式即可開啟ADC 9個通道DMA方式迴圈取樣，取樣值存放在ADC_Value[Channel_Num]陣列中，讀取陣列即可得到取樣值，進行後續的資料處理。