如何用STM32分离两个相减的信号，具体代码

以下是一个使用STM32 HAL库实现的简单示例代码，用于从两个ADC通道读取输入信号，然后将其相减并输出到DAC通道：

#include "stm32f4xx_hal.h"

ADC_HandleTypeDef hadc1;
ADC_HandleTypeDef hadc2;
DAC_HandleTypeDef hdac;

void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DMA_Init(void);
static void MX_ADC1_Init(void);
static void MX_ADC2_Init(void);
static void MX_DAC_Init(void);

int16_t ADC1_Data[256];
int16_t ADC2_Data[256];
int16_t DAC_Data[256];

int main(void)
{
  HAL_Init();
  SystemClock_Config();
  MX_GPIO_Init();
  MX_DMA_Init();
  MX_ADC1_Init();
  MX_ADC2_Init();
  MX_DAC_Init();

  HAL_ADC_Start_DMA(&hadc1, (uint32_t*)ADC1_Data, 256);
  HAL_ADC_Start_DMA(&hadc2, (uint32_t*)ADC2_Data, 256);

  while (1)
  {
    for (int i = 0; i < 256; i++)
    {
      DAC_Data[i] = ADC1_Data[i] - ADC2_Data[i];
    }
    HAL_DAC_Start_DMA(&hdac, DAC_Channel_1, (uint32_t*)DAC_Data, 256, DAC_ALIGN_12B_R);
  }
}

void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = 25;
  RCC_OscInitStruct.PLL.PLLN = 336;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = 7;
  HAL_RCC_OscConfig(&RCC_OscInitStruct);

  RCC_ClkInitStruct.ClockType = 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_DIV4;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;
  HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5);
}

static void MX_ADC1_Init(void)
{
  ADC_ChannelConfTypeDef sConfig = {0};

  __HAL_RCC_ADC1_CLK_ENABLE();

  hadc1.Instance = ADC1;
  hadc1.Init.ClockPrescaler = ADC_CLOCK_SYNC_PCLK_DIV2;
  hadc1.Init.Resolution = ADC_RESOLUTION_12B;
  hadc1.Init.ScanConvMode = ENABLE;
  hadc1.Init.ContinuousConvMode = ENABLE;
  hadc1.Init.DiscontinuousConvMode = DISABLE;
  hadc1.Init.NbrOfDiscConversion = 0;
  hadc1.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
  hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;
  hadc1.Init.DataAlign = ADC_DATAALIGN_RIGHT;
  hadc1.Init.NbrOfConversion = 1;
  hadc1.Init.DMAContinuousRequests = ENABLE;
  hadc1.Init.EOCSelection = ADC_EOC_SINGLE_CONV;
  HAL_ADC_Init(&hadc1);

  sConfig.Channel = ADC_CHANNEL_1;
  sConfig.Rank = 1;
  sConfig.SamplingTime = ADC_SAMPLETIME_3CYCLES;
  sConfig.Offset = 0;
  HAL_ADC_ConfigChannel(&hadc1, &sConfig);
}

static void MX_ADC2_Init(void)
{
  ADC_ChannelConfTypeDef sConfig = {0};

  __HAL_RCC_ADC2_CLK_ENABLE();

  hadc2.Instance = ADC2;
  hadc2.Init.ClockPrescaler = ADC_CLOCK_SYNC_PCLK_DIV2;
  hadc2.Init.Resolution = ADC_RESOLUTION_12B;
  hadc2.Init.ScanConvMode = ENABLE;
  hadc2.Init.ContinuousConvMode = ENABLE;
  hadc2.Init.DiscontinuousConvMode = DISABLE;
  hadc2.Init.NbrOfDiscConversion = 0;
  hadc2.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
  hadc2.Init.ExternalTrigConv = ADC_SOFTWARE_START;
  hadc2.Init.DataAlign = ADC_DATAALIGN_RIGHT;
  hadc2.Init.NbrOfConversion = 1;
  hadc2.Init.DMAContinuousRequests = ENABLE;
  hadc2.Init.EOCSelection = ADC_EOC_SINGLE_CONV;
  HAL_ADC_Init(&hadc2);

  sConfig.Channel = ADC_CHANNEL_2;
  sConfig.Rank = 1;
  sConfig.SamplingTime = ADC_SAMPLETIME_3CYCLES;
  sConfig.Offset = 0;
  HAL_ADC_ConfigChannel(&hadc2, &sConfig);
}

static void MX_DAC_Init(void)
{
  DAC_ChannelConfTypeDef sConfig = {0};

  __HAL_RCC_DAC_CLK_ENABLE();

  hdac.Instance = DAC;
  HAL_DAC_Init(&hdac);

  sConfig.DAC_Trigger = DAC_TRIGGER_NONE;
  sConfig.DAC_OutputBuffer = DAC_OUTPUTBUFFER_ENABLE;
  HAL_DAC_ConfigChannel(&hdac, &sConfig, DAC_CHANNEL_1);
}

static void MX_DMA_Init(void)
{
  __HAL_RCC_DMA1_CLK_ENABLE();

  HAL_NVIC_SetPriority(DMA1_Stream0_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(DMA1_Stream0_IRQn);
}

void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc)
{
  // Do nothing
}

void HAL_ADC_ErrorCallback(ADC_HandleTypeDef *hadc)
{
  // Do nothing
}

void HAL_DAC_ConvCpltCallbackCh1(DAC_HandleTypeDef* hdac)
{
  // Do nothing
}

void HAL_DAC_ErrorCallbackCh1(DAC_HandleTypeDef* hdac)
{
  // Do nothing
}

void DMA1_Stream0_IRQHandler(void)
{
  HAL_DMA_IRQHandler(&hdac);
  HAL_DMA_IRQHandler(&hadc1);
  HAL_DMA_IRQHandler(&hadc2);
}

这个代码将从ADC1和ADC2通道读取模拟输入信号，然后将其传输到内存缓冲区中。然后，使用一个循环来计算两个缓冲区的差值，并将结果传输到DAC通道以输出模拟信号。注意，这个示例并不是一个完整的实现，你需要根据你的具体应用场景进行修改和优化。