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理论上来说，配置adc由外部时钟控制加上dma转运可以使采样频率为100khz，可以采集到最高频率为50khz的信号。然后运用msp库中的fft函数，可以得到输入波形对应的频率以及峰峰值。那么理论上来说，我将adc采样频率改为200khz，应该可以采样到100khz波形。但是实际上遇到的问题是依旧只能采样到50khz以内，如果采样60khz波形，会在40khz波形对应的地方有最大值。同时如果采样40khz的波形，与100khz采样频率使对应的下标相同（如果我采样1024组数据，采样频率为100khz，此时分辨率为976hz,那么40khz对应的下标为400附近，但我此时将采样频率调整至200khz，40khz波形对应的下标依旧为400附近，理论上为200附近才对），困扰许久，求解答，代码如下（应该不是由于重装载值以及分频值配置错误的原因）：/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "adc.h"
#include "dma.h"
#include "tim.h"
#include "usart.h"
#include "gpio.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "arm_math.h"
#include "arm_const_structs.h"
#include "stdio.h"
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
#define FFT_LENGTH 1024
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
uint16_t adcBuff[FFT_LENGTH];
float fft_inputbuf[FFT_LENGTH * 2];
float fft_outputbuf[FFT_LENGTH];
__IO uint8_t AdcConvEnd = 0;
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_DMA_Init();
MX_ADC1_Init();
MX_TIM2_Init();
MX_USART1_UART_Init();
MX_TIM4_Init();
MX_ADC2_Init();
/* USER CODE BEGIN 2 */
HAL_TIM_Base_Start(&htim2);
HAL_ADC_Start_DMA(&hadc1, (uint32_t *)adcBuff, FFT_LENGTH);
while (!AdcConvEnd)
;
for (int i = 0; i < FFT_LENGTH; i++)
{
fft_inputbuf[i * 2] = adcBuff[i] * 3.3 / 4096;//实部赋值，* 3.3 / 4096是为了将ADC采集到的值转换成实际电压
fft_inputbuf[i * 2 + 1] = 0;//虚部赋值，固定为0.
}
arm_cfft_f32(&arm_cfft_sR_f32_len1024, fft_inputbuf, 0, 1);
arm_cmplx_mag_f32(fft_inputbuf, fft_outputbuf, FFT_LENGTH);
fft_outputbuf[0] /= 1024;
for (int i = 1; i < FFT_LENGTH; i++)
{
fft_outputbuf[i] /= 512;
}
for (int i = 0; i < FFT_LENGTH; i++)//输出各次谐波幅值
{
printf("%d:\t%.2f\r\n", i, fft_outputbuf[i]);
}
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
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);
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
RCC_OscInitStruct.PLL.PLLM = 8;
RCC_OscInitStruct.PLL.PLLN = 168;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
RCC_OscInitStruct.PLL.PLLQ = 4;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Initializes 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();
}
}
/* USER CODE BEGIN 4 */
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
if (htim == (&htim4))
{
ad7606_IRQSrc();
}
}
/* USER CODE END 4 */
/**
* @brief This function is executed in case of error occurrence.
* @retval None
*/
void Error_Handler(void)
{
/* USER CODE BEGIN Error_Handler_Debug */
/* User can add his own implementation to report the HAL error return state */
__disable_irq();
while (1)
{
}
/* USER CODE END Error_Handler_Debug */
}
#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\r\n", file, line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
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发表于 2025-7-27 22:39:55
发表于 2025-7-28 09:22:56
楼主
