f103使用hal库进行ADC读取电压数值不对

qq297880617 · 发表于 2019-9-25 19:15:28

读取5V电压，经过电路处理后进入PC0的电压大概是0.22V左右，但是读取出来的电压是3.16V左右，不清楚哪个环节出了问题，求教，下面附上代码电路

ADC_HandleTypeDef hadc1;
ADCDataTypedef ADC1Flag;
/* ADC1 init function */
void MX_ADC1_Init(void)
{
  ADC_ChannelConfTypeDef sConfig;
  hadc1.Instance = ADC1;
  hadc1.Init.ScanConvMode = ADC_SCAN_DISABLE;
  hadc1.Init.ContinuousConvMode = DISABLE;
  hadc1.Init.DiscontinuousConvMode = DISABLE;
  hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;
  hadc1.Init.DataAlign = ADC_DATAALIGN_RIGHT;
  hadc1.Init.NbrOfConversion = 1;
  if (HAL_ADC_Init(&hadc1) != HAL_OK)
  {
_Error_Handler(__FILE__, __LINE__);
  }
  sConfig.Channel = ADC_CHANNEL_10;
  sConfig.Rank = ADC_REGULAR_RANK_1;
  sConfig.SamplingTime = ADC_SAMPLETIME_1CYCLE_5;
  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
  {
_Error_Handler(__FILE__, __LINE__);
  }
HAL_ADCEx_Calibration_Start(&hadc1);
}

void HAL_ADC_MspInit(ADC_HandleTypeDef* adcHandle)
{

  GPIO_InitTypeDef GPIO_InitStruct;
  if(adcHandle->Instance==ADC1)
  {
__HAL_RCC_ADC1_CLK_ENABLE();


GPIO_InitStruct.Pin = GPIO_PIN_0;
GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);

  }
}

void HAL_ADC_MspDeInit(ADC_HandleTypeDef* adcHandle)
{

if(adcHandle->Instance==ADC1)
__HAL_RCC_ADC1_CLK_DISABLE();
HAL_GPIO_DeInit(GPIOC, GPIO_PIN_0);

  }
}

下面是串口发送部分

else if(rxBuffer[i+1] == 0x05 && rxBuffer[i+2] == 0x01 && rxBuffer[i+3] == 0x01)    // 46 05 01 01 ADC
{

         ADC1Flag.ADCBuffer = 0;
   HAL_ADC_Start(&hadc1);
         HAL_ADC_PollForConversion(&hadc1, 50);
   if(HAL_IS_BIT_SET(HAL_ADC_GetState(&hadc1), HAL_ADC_STATE_REG_EOC))
   {
         ADC1Flag.ADCBuffer = HAL_ADC_GetValue(&hadc1);
         My_printf("ADC2 Reading : %d \r\n",ADC1Flag.ADCBuffer);
   My_printf("PA6 Voltage : %.4f \r\n",ADC1Flag.ADCBuffer*3.3f/4095);
   }
}

输出内容：

ADC2 Reading : 3922

PA6 Voltage : 3.1606

ADC2 Reading : 3922

PA6 Voltage : 3.1606