STM32F407内部温度偏差太大

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power568 提问时间：2016-3-24 16:58 /

各位有没有使用过F407内部的温度传感器，今天测试了下，室温在15度左右，采集内码值为1220，换算为温度为：

T = （Vsense – V25）/AVG_Slope +25 = 114.16,

V25 = 0.76V；

AVG_Slope = 2.5mv/℃

这太离谱了吧，不知道是哪里出了问题；

按照官方给的公式，要是温度在15~30摄氏度之间，转换内码值就需要在910~960之间才可以

求高手指点…

代码如下：

static void AdcPinComInit(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
ADC_CommonInitTypeDef ADC_InitStructure;

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1 | RCC_APB2Periph_ADC2, ENABLE);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3 | GPIO_Pin_4;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure);

ADC_InitStructure.ADC_Mode = ADC_DualMode_RegSimult;
ADC_InitStructure.ADC_Prescaler = ADC_Prescaler_Div2;
ADC_InitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_1;
ADC_InitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_10Cycles;
ADC_CommonInit(&ADC_InitStructure);
}

static void AdcDmaInit(void)
{
DMA_InitTypeDef DMA_InitStructure;

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);

  DMA_InitStructure.DMA_Channel = DMA_Channel_0;
  DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)AdcSampDmaBuf;
  DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADC_CCR_ADDRESS;
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
  DMA_InitStructure.DMA_BufferSize = ADC_DMA_BUF_LEN;
  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_Enable;    ////
  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);
}

static void Adc1ChxConfig(void)
{
  ADC_InitTypeDef ADC_InitStructure;

  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_ExternalTrigConv = ADC_ExternalTrigConv_T1_CC1;
  ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
  ADC_InitStructure.ADC_NbrOfConversion = 3;
  ADC_Init(ADC1, &ADC_InitStructure);

  //// ADC1 regular channels configuration
  ADC_RegularChannelConfig(ADC1, ADC_Channel_TempSensor, 1, ADC_SampleTime_15Cycles);
  ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 2, ADC_SampleTime_15Cycles);
  ADC_RegularChannelConfig(ADC1, ADC_Channel_3, 3, ADC_SampleTime_15Cycles);
}

static void Adc2ChxConfig(void)
{
  ADC_InitTypeDef ADC_InitStructure;

  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_ExternalTrigConv = ADC_ExternalTrigConv_T1_CC1;
  ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
  ADC_InitStructure.ADC_NbrOfConversion = 3;
  ADC_Init(ADC2, &ADC_InitStructure);

  //// ADC2 regular channels configuration
  ADC_RegularChannelConfig(ADC2, ADC_Channel_2, 1, ADC_SampleTime_15Cycles);
  ADC_RegularChannelConfig(ADC2, ADC_Channel_4, 2, ADC_SampleTime_15Cycles);
  ADC_RegularChannelConfig(ADC2, ADC_Channel_2, 3, ADC_SampleTime_15Cycles);
}