ADC DAM 两路采样，采样值有时准确，有时误差离谱

只看该作者 · 2014-3-13 18:49

#include "adc_driver.h"
#include "time_driver.h"
#define ADC1_DR_ADDRESS ((uint32_t)0x40012458)
__IO uint16_t ADC_ConvertedValue[2][10];                   //采样数组，两路，每一路采样十次
float Battery_ADC,Photoactor_ADC,Photoactor_ADC1, Battery_ADC1;    实际电压采样变量
/*
*  */
void ADC_DMA_Configuration(void)
{
ADC_InitTypeDef ADC_InitStructure;                   //1
GPIO_InitTypeDef GPIO_InitStructure;                //1
DMA_InitTypeDef DMA_InitStructure;                      //1
  /*------------------------ DMA1 configuration ------------------------------*/
  /* Enable DMA1 clock */
  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE); //
  /* DMA1 channel1 configuration */
  DMA_DeInit(DMA1_Channel1);  //DAMÍ¨µÀ³õÊ¼»¯
  DMA_InitStructure.DMA_PeripheralBaseAddr = ADC1_DR_ADDRESS;  //
  DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)&ADC_ConvertedValue;//
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;             //´
  DMA_InitStructure.DMA_BufferSize = N*M;                            //
  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_M2M = DMA_M2M_Disable;       //
  DMA_Init(DMA1_Channel1, &DMA_InitStructure);       //

  /*----------------- ADC1 configuration with DMA enabled --------------------*/
  /* Enable the HSI oscillator */
  RCC_HSICmd(ENABLE);                                                 //
  /* Enable GPIOA clock */
  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);  //3
  /* Configure PA.1 (ADC Channel1) in analog mode */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;    //4
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;  //5
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
  GPIO_Init(GPIOA, &GPIO_InitStructure);  //
  /*Enable GPIOB clock */
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);
GPIO_InitStructure.GPIO_Pin=GPIO_Pin_15;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOB, &GPIO_InitStructure);

  /* Enable ADC1 clock */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);//4
  /* ADC1 configuration */                         //
  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 = 2;    //
  ADC_Init(ADC1, &ADC_InitStructure);

  /* ADC1 regular channel18 configuration */       //
  ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 1, ADC_SampleTime_384Cycles  ); //
ADC_RegularChannelConfig(ADC1, ADC_Channel_21 ,2,ADC_SampleTime_384Cycles  );
  /* Enable the request after last transfer for DMA Circular mode */
  ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE);

  /* Enable ADC1 DMA */
  ADC_DMACmd(ADC1, ENABLE);  //Ê¹ÄÜADC_DAM
  /* Enable ADC1 */
  ADC_Cmd(ADC1, ENABLE);  //Ê¹ÄÜADC
  /* Wait until the ADC1 is ready */
while(ADC_GetFlagStatus(ADC1, ADC_FLAG_ADONS) == RESET)
  {
  }
  /* Enable DMA1 channel1 */
  DMA_Cmd(DMA1_Channel1, ENABLE);
  /* Start ADC1 Software Conversion */
  ADC_SoftwareStartConv(ADC1);
}

      /*»采样二进制转换成十进制函数*/
float GetVolt(float ADC_ConvertedValue)
  {
   return(float)(ADC_ConvertedValue*3.3/4096);
}

float sum_guang,sum_volt;    //平均电压变样
/ 前5次光敏，电池电压数据总和函数
void  filter (void)
{    int count;
      for(count=0;count<N;count=count+2)
   {

         sum_volt=(float)ADC_ConvertedValue[0][count]+sum_volt;
      }

      for(count=1;count<N;count=count+2)
   {

         sum_guang+=(float)ADC_ConvertedValue[0][count];
      }

}
后五个光敏，电池电压数据总和函数
void  filter1 (void)
{       int count;

      for(count=0;count<N;count=count+2)
   {

         sum_volt+=(float)ADC_ConvertedValue[1][count];
      }

      for(count=1;count<N;count=count+2)
   {

         sum_guang+=(float)ADC_ConvertedValue[1][count];
      }
}
光敏，电池电压采样函数

void  sampling ()
{ float sum_guang1,sum_volt1;
   ADC_DMACmd(ADC1, ENABLE);
ADC_DMA_Configuration();
//Clock_Wait_10ms(1);
while(DMA_GetFlagStatus(DMA1_FLAG_TC1)==RESET);
   ADC_Cmd(ADC1, DISABLE);
   ADC_DMACmd(ADC1, DISABLE);
filter();
filter1();
// ADC_Cmd(ADC1, DISABLE);
   //ADC_DMACmd(ADC1, DISABLE);
  sum_guang1=sum_guang/10;
  sum_volt1=sum_volt/10;
   Battery_ADC= GetVolt(sum_volt1);
Clock_Wait_10ms(1);
  Photoactor_ADC= GetVolt(sum_guang1);
  sum_guang=0;
  sum_volt=0;
  // while(Battery_ADC>3.5&Photoactor_ADC>4);
//while(Battery_ADC<0.1&Photoactor_ADC<0.08);
//Battery_ADC1=Battery_ADC;
  //Photoactor_ADC1= Photoactor_ADC;


}

求指点，我用KEIL设断点发现读出的实际电压，有时准确，有时不准