请教各位大哥，我在用STM32F103中的DMA方式采集单片机内部温度传感器的温度值时，采集的值和原子哥例程中的不同，是个负值，....

xiaobakang · 发表于 2017-2-13 16:21:48

#include "adc.h"

__IO uint16_t ADCConvertedValue[20]={0};

void ADC_init(void)
{

ADC_InitTypeDef ADC_InitStructure;

  // GPIO_InitTypeDef GPIO_InitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE );    //使能ADC1通道时钟
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE); //使能DMA传输

RCC_ADCCLKConfig(RCC_PCLK2_Div6); //设置ADC分频因子6 72M/6=12,ADC最大时间不能超过14M

DMA_init();

/* ADC1 configuration ------------------------------------------------------*/
ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
ADC_InitStructure.ADC_ScanConvMode = DISABLE;//ENABLE;
ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfChannel = 1;
ADC_Init(ADC1, &ADC_InitStructure);

/* ADC1 regular channel16 configuration */
ADC_RegularChannelConfig(ADC1, ADC_Channel_16, 1, ADC_SampleTime_239Cycles5);

ADC_TempSensorVrefintCmd(ENABLE); //开启内部温度传感器，检测内部温度
/* Enable ADC1 DMA */
ADC_DMACmd(ADC1, ENABLE);

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

  /* Enable ADC1 reset calibration register */
ADC_ResetCalibration(ADC1);
/* Check the end of ADC1 reset calibration register */

while(ADC_GetResetCalibrationStatus(ADC1));

/* Start ADC1 calibration */
ADC_StartCalibration(ADC1);
/* Check the end of ADC1 calibration */
while(ADC_GetCalibrationStatus(ADC1));

/* Start ADC1 Software Conversion */
ADC_SoftwareStartConvCmd(ADC1, ENABLE);
}

void DMA_init(void)
{

DMA_InitTypeDef DMA_InitStructure;

DMA_DeInit(DMA1_Channel1);
DMA_InitStructure.DMA_PeripheralBaseAddr = ADC1_DR_Address;
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)&ADCConvertedValue;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
DMA_InitStructure.DMA_BufferSize = 20;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Disable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal ;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_Init(DMA1_Channel1, &DMA_InitStructure);

/* Enable DMA1 channel1 */
DMA_Cmd(DMA1_Channel1, ENABLE);
}

float Get_value(void)
{
   u8 i=0;
   u32 value_temp=0;
   double value=0;
   short temp_value=0;

   for(i=0;i<20;i++)
      {
   value_temp+=ADCConvertedValue[i];
   }
   value_temp= value_temp/20;
   value=(float)value_temp*(3.3/4096);
   value=(1.43-value)/0.0043+25;
   temp_value=value*100;
      return temp_value;
}

TGuest · 发表于 2017-2-14 17:24:13

单步跟踪看看value_temp= value_temp/20;这个值是多少。。

TGuest · 发表于 2017-2-14 17:26:45

而且你这个写的有问题 DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)&ADCConvertedValue; ADCConvertedValue【】就是一个数组，ADCConvertedValue这个数组的名字就是地址了，你在加一个取地址符&肯定是不对的。