2019年02月12日 | STM32——多通道ADC的DMA方式采集方法

前言：

最近在调试STM32F205芯片ADC多通道DMA方式采集数据，总结下STM32多通道ADC的DMA方式采集的使用方法。

硬件平台：STM32F205

软件平台：keil v5

函数库：标准库

多通道ADC的配置

#define Channel_Num  9 //ＡＤＣ的通道数，本例使用9个通道

#define Sample_Num  10 //采样次数，本例使用平均滤波，采样10次取均值

u16 ADC_ConvertedValue[Sample_Num][Channel_Num];//ADC采集数据的缓存

uint16_t ADC_Value[Channel_Num]={0};//9个ADC通道的采样值

下面为ADC及DMA的详细配置函数。

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 应配置为Sample_Num*Channel_Num，而不是通道数。

下面是均值滤波函数。

u16 ReadADCAverageValue(uint16_t Channel)

{

    uint8_t i;

    uint32_t sum = 0;

    for(i=0; i

    {

     sum+=ADC_ConvertedValue[i][Channel];

    }

    return (sum/Sample_Num);

}

　　最后，调用ADC_SoftwareStartConv(ADC1)函数即可开启ADC 9个通道DMA方式循环采样，采样值存放在ADC_Value[Channel_Num]数组中，读取数组即可得到采样值，进行后续的数据处理。