STM32 的CMSIS

CMSIS（Cortex Microcontroller Software Interface Standard）是一套为Cortex-M处理器系列提供统一软件接口的标准。CMSIS包括了处理器核心（Core）、DSP库、RTOS（Real-Time Operating System）等组件。在STM32微控制器上，CMSIS DSP库是用于数字信号处理的库，包含了许多用于信号处理、滤波、FFT等操作的函数。

FFT计算交流信号基波频率的代码

#include "main.h"
#include "stm32f4xx_hal.h"
#include "arm_math.h"

#define ADC_BUFFER_SIZE 1024
#define SAMPLE_RATE     10000  // 采样率

ADC_HandleTypeDef hadc1;
DMA_HandleTypeDef hdma_adc1;

uint16_t adcBuffer[ADC_BUFFER_SIZE];
float32_t fftInput[ADC_BUFFER_SIZE];
float32_t fftOutput[ADC_BUFFER_SIZE];
arm_rfft_instance_f32 fftInstance;
float32_t maxValue;
uint32_t maxIndex;

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_FFT_Init(void);

int main(void)
{
  HAL_Init();
  SystemClock_Config();

  MX_GPIO_Init();
  MX_DMA_Init();
  MX_ADC1_Init();
  MX_FFT_Init();

  HAL_ADC_Start_DMA(&hadc1, (uint32_t*)adcBuffer, ADC_BUFFER_SIZE);

  while (1)
  {
    // 等待DMA传输完成
    while (HAL_DMA_PollForTransfer(&hdma_adc1, HAL_DMA_FULL_TRANSFER, HAL_MAX_DELAY) != HAL_OK);

    // 将ADC数据复制到FFT输入缓冲区
    for (uint16_t i = 0; i < ADC_BUFFER_SIZE; i++) {
      fftInput[i] = adcBuffer[i];
    }

    // 执行FFT
    arm_rfft_f32(&fftInstance, fftInput, fftOutput);

    // 查找最大幅度的频率
    arm_max_f32(fftOutput, ADC_BUFFER_SIZE, &maxValue, &maxIndex);

    // 计算对应的频率
    float32_t frequency = (float32_t)maxIndex * SAMPLE_RATE / ADC_BUFFER_SIZE;

    // 输出结果
    printf("Dominant frequency: %.2f Hz\n", frequency);

    // 可添加其他任务

    // 重新启动ADC DMA传输
    HAL_ADC_Start_DMA(&hadc1, (uint32_t*)adcBuffer, ADC_BUFFER_SIZE);
  }
}

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

  /** Configure the main internal regulator output voltage
  */
  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  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 = 8;
  RCC_OscInitStruct.PLL.PLLN = 360;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = 7;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure the CPU, AHB and APB buses 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_DIV4;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK)
  {
    Error_Handler();
  }
}

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

  __HAL_RCC_ADC1_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();

  /** Configure the global features of the ADC (Clock, Resolution, Data Alignment and number of conversion)
  */
  hadc1.Instance = ADC1;
  hadc1.Init.ClockPrescaler = ADC_CLOCK_SYNC_PCLK_DIV4;
  hadc1.Init.Resolution = ADC_RESOLUTION_12B;
  hadc1.Init.ScanConvMode = DISABLE;
  hadc1.Init.ContinuousConvMode = ENABLE;
  hadc1.Init.DiscontinuousConvMode = DISABLE;
  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;

  if (HAL_ADC_Init(&hadc1) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure for the selected ADC regular channel its corresponding rank in the sequencer and its sample time.
  */
  sConfig.Channel = ADC_CHANNEL_0;
  sConfig.Rank = 1;
  sConfig.SamplingTime = ADC_SAMPLETIME_3CYCLES;

  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }
}

static void MX_DMA_Init(void)
{
  __HAL_RCC_DMA2_CLK_ENABLE();

  HAL_NVIC_SetPriority(DMA2_Stream0_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(DMA2_Stream0_IRQn);
}

static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  __HAL_RCC_GPIOA_CLK_ENABLE();

  /**Configure GPIO pin : PA0
  */
  GPIO_InitStruct.Pin = GPIO_PIN_0;
  GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
}

static void MX_FFT_Init(void)
{
  arm_rfft_init_f32(&fftInstance, ADC_BUFFER_SIZE, 0, 1);
}

void Error_Handler(void)
{
  __disable_irq();
  while (1)
  {
  }
}

#ifdef  USE_FULL_ASSERT
void assert_failed(uint8_t *file, uint32_t line)
{
  /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  while (1)
  {
  }
}
#endif