stm32F406VET6测频率代码

以下是使用STM32F406VET6测量频率的代码，使用TIM2计数器：

#include "stm32f4xx.h"

TIM_HandleTypeDef htim2;
uint32_t frequency;

void SystemClock_Config(void);

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

  __HAL_RCC_TIM2_CLK_ENABLE();

  htim2.Instance = TIM2;
  htim2.Init.Prescaler = 0;
  htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim2.Init.Period = 0xFFFFFFFF;
  htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  HAL_TIM_Base_Init(&htim2);

  HAL_TIM_Base_Start(&htim2);

  while (1)
  {
    frequency = HAL_TIM_ReadCapturedValue(&htim2, TIM_CHANNEL_1);
    printf("Frequency: %d Hz\n", frequency);
    HAL_Delay(1000);
  }
}

void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct;
  RCC_ClkInitTypeDef RCC_ClkInitStruct;

  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = 16;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
  RCC_OscInitStruct.PLL.PLLM = 16;
  RCC_OscInitStruct.PLL.PLLN = 336;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
  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);
}

在这个代码中，我们使用TIM2计数器来测量频率。代码中的while循环通过HAL_TIM_ReadCapturedValue函数读取TIM2计数器的值，并将其作为频率输出。

请注意，此代码仅供参考。具体实现方式可能因您的硬件配置和应用程序要求而有所不同。