我用STM32f303r6t6, pa0,pa1做差分输入；用三个10k电阻串起来取电压，pa0+;pa1-;调节中间电阻，改变取样电压；加上图发不上来
图看工程附在最后
初始化代码；

/* Includes ------------------------------------------------------------------*/
#include "adc.h"
#include "gpio.h"
#include "dma.h"
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
ADC_HandleTypeDef hadc1;
DMA_HandleTypeDef hdma_adc1;
/* ADC1 init function */
void MX_ADC1_Init(void)
{
  ADC_ChannelConfTypeDef sConfig;
    /**Common config
    */
  hadc1.Instance = ADC1;
  hadc1.Init.ScanConvMode = ADC_SCAN_DISABLE;
  hadc1.Init.ContinuousConvMode = ENABLE;
  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();
  }
    /**Configure Regular Channel
    */
  sConfig.Channel = ADC_CHANNEL_3;
  sConfig.Rank = 1;
  sConfig.SamplingTime = ADC_SAMPLETIME_71CYCLES_5;
  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }
}
void HAL_ADC_MspInit(ADC_HandleTypeDef* adcHandle)
{
  GPIO_InitTypeDef GPIO_InitStruct;
  if(adcHandle->Instance==ADC1)
  {
  /* USER CODE BEGIN ADC1_MspInit 0 */
  /* USER CODE END ADC1_MspInit 0 */
    /* Peripheral clock enable */
    __HAL_RCC_ADC1_CLK_ENABLE();
  
    /**ADC1 GPIO Configuration   
    PA3     ------> ADC1_IN3
    */
    GPIO_InitStruct.Pin = GPIO_PIN_3;
    GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
    /* Peripheral DMA init*/
  
    hdma_adc1.Instance = DMA1_Channel1;
    hdma_adc1.Init.Direction = DMA_PERIPH_TO_MEMORY;
    hdma_adc1.Init.PeriphInc = DMA_PINC_DISABLE;
    hdma_adc1.Init.MemInc = DMA_MINC_ENABLE;
    hdma_adc1.Init.PeriphDataAlignment = DMA_PDATAALIGN_WORD;
    hdma_adc1.Init.MemDataAlignment = DMA_MDATAALIGN_WORD;
    hdma_adc1.Init.Mode = DMA_CIRCULAR;
    hdma_adc1.Init.Priority = DMA_PRIORITY_LOW;
    if (HAL_DMA_Init(&hdma_adc1) != HAL_OK)
    {
      Error_Handler();
    }
    __HAL_LINKDMA(adcHandle,DMA_Handle,hdma_adc1);
  /* USER CODE BEGIN ADC1_MspInit 1 */
  /* USER CODE END ADC1_MspInit 1 */
  }
}
void HAL_ADC_MspDeInit(ADC_HandleTypeDef* adcHandle)
{
  if(adcHandle->Instance==ADC1)
  {
  /* USER CODE BEGIN ADC1_MspDeInit 0 */
  /* USER CODE END ADC1_MspDeInit 0 */
    /* Peripheral clock disable */
    __HAL_RCC_ADC1_CLK_DISABLE();
  
    /**ADC1 GPIO Configuration   
    PA3     ------> ADC1_IN3
    */
    HAL_GPIO_DeInit(GPIOA, GPIO_PIN_3);
    /* Peripheral DMA DeInit*/
    HAL_DMA_DeInit(adcHandle->DMA_Handle);
  }
  /* USER CODE BEGIN ADC1_MspDeInit 1 */
  /* USER CODE END ADC1_MspDeInit 1 */
}

主代码
******************************************************************************
  */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "stm32f1xx_hal.h"
#include "adc.h"
#include "dma.h"
#include "usart.h"
#include "gpio.h"
/* USER CODE BEGIN Includes */
#include <string.h>
   #include "math.h"
   #include "stdio.h"
   ///   TIM_HandleTypeDef    TimHandle;
    #ifdef __GNUC__
    #define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
    #else
    #define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
    #endif
     PUTCHAR_PROTOTYPE
     {
      HAL_UART_Transmit(&huart1 , (uint8_t *)&ch, 1, 0xFFFF);
      return ch;
     }

/* USER CODE END Includes */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
/* Private variables ---------------------------------------------------------*/
   
    uint32_t   aResultDMA[12];
   
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
  void SystemClock_Config(void);
  void Error_Handler(void);
/* USER CODE BEGIN PFP */
/* Private function prototypes -----------------------------------------------*/
/* USER CODE END PFP */
/* USER CODE BEGIN 0 */

float adZhonXifu11A(void)
{
unsigned char i ,j;
uint16_t addata[12];
float fluc1;
uint16_t uiNc1;
uint16_t uiTol;
for(i=0;i<11;i++){addata= (uint16_t)aResultDMA[i*3];}
for(j=0;j<10;j++)
{
for(i=0;i<11-j;i++)
{
  if(addata>addata[i+1])
  {
   uiNc1=addata;
   addata=addata[i+1];
   addata[i+1]=uiNc1;
  }
}//for(i=0;<11-j;i++)
}//for(j=0;j<10;j++)
fluc1=(float)addata[5];
uiNc1=(uint16_t)(fluc1*0.03);
if(uiNc1<5) uiNc1=5;
uiTol=addata[5]; i=1;
for(j=6;j<11;j++)
{
if((addata[j]-addata[5])<uiNc1)
{
  i++;
  uiTol=uiTol+addata[j];
}
}
for(j=0;j<5;j++)
{
if((addata[5]-addata[j])<uiNc1)
{
  i++;
  uiTol=uiTol+addata[j];
}
}
fluc1=((float)uiTol)/((float)i);
return(fluc1);  
}


/* USER CODE END 0 */
int main(void)
{
  /* USER CODE BEGIN 1 */
  uint16_t uiNdata;
float flNdata;
  /* USER CODE END 1 */
  /* MCU Configuration----------------------------------------------------------*/
  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();
  /* Configure the system clock */
  SystemClock_Config();
  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_DMA_Init();
  MX_ADC1_Init();
  MX_USART1_UART_Init();
  /* USER CODE BEGIN 2 */
    HAL_ADC_Start_DMA(&hadc1, aResultDMA, 11);

  /* USER CODE END 2 */
  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
  /* USER CODE END WHILE */
  /* USER CODE BEGIN 3 */
    flNdata=adZhonXifu11A();
    uiNdata=(uint16_t)flNdata;
  
    printf(" A Chanel  Test OK ");
     printf("0x%02X", uiNdata);
  
     HAL_Delay(1);
  
  
  }
  /* USER CODE END 3 */
}
/** System Clock Configuration
*/
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct;
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  RCC_PeriphCLKInitTypeDef PeriphClkInit;
    /**Initializes the CPU, AHB and APB busses clocks
    */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.Prediv1Source = RCC_PREDIV1_SOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
  RCC_OscInitStruct.PLL2.PLL2State = RCC_PLL_NONE;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }
    /**Initializes the CPU, AHB and APB busses clocks
    */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
  {
    Error_Handler();
  }
  PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_ADC;
  PeriphClkInit.AdcClockSelection = RCC_ADCPCLK2_DIV6;
  if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
  {
    Error_Handler();
  }
    /**Configure the Systick interrupt time
    */
  HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000);
    /**Configure the Systick
    */
  HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);
    /**Configure the Systick interrupt time
    */
  __HAL_RCC_PLLI2S_ENABLE();
  /* SysTick_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0);
}
/* USER CODE BEGIN 4 */
/* USER CODE END 4 */
/**
  * @brief  This function is executed in case of error occurrence.
  * @param  None
  * @retval None
  */
void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler */
  /* User can add his own implementation to report the HAL error return state */
  while(1)
  {
  }
  /* USER CODE END Error_Handler */
}
#ifdef USE_FULL_ASSERT
/**
   * @brief Reports the name of the source file and the source line number
   * where the assert_param error has occurred.
   * @param file: pointer to the source file name
   * @param line: assert_param error line source number
   * @retval None
   */
void assert_failed(uint8_t* file, uint32_t line)
{
  /* USER CODE BEGIN 6 */
  /* User can add his own implementation to report the file name and line number,
    ex: printf("Wrong parameters value: file %s on line %d ", file, line) */
  /* USER CODE END 6 */
}
#endif