利用脉冲位宽调制技术和一级滤波电路实现正弦波输出

利用PWM和RC滤波电路输出正弦波

流程图

主程序
中断部分

1、初始化硬件

(1)时钟

使能RCC，选择外部高速晶振
将HCLK配置为最大的84MHz

(2)PWM

使能TIM1，将PWM设为20KHz，将死区设置为25ns
注意：为防止开关不同步导致的短路，需要设置“死区”

PWM频率计算公式：\(频率 = \frac{计时器频率}{(预分频 + 1) \times (重装载值 + 1)}\)
此时计时器频率为84MHz，预分频数值为0，重装载值为4199，所以PWM频率为20KHz

(3)TIM

将TIM2的时钟源设置为内部时钟，重装载值设置为4199
使能TIM2中断

(4)代码部分

在主循环外部对TIM进行初始化

  /* USER CODE BEGIN 2 */
	HAL_TIM_Base_Start_IT(&htim2);//开启定时器2中断
	HAL_TIM_PWM_Start (&htim1,TIM_CHANNEL_1);//开启四路pwm波
	HAL_TIMEx_PWMN_Start (&htim1,TIM_CHANNEL_1);
  /* USER CODE END 2 */

2、写入代码

(1)启用`TIM`

  /* USER CODE BEGIN 2 */
	HAL_TIM_Base_Start_IT(&htim2);//开启定时器2中断
	HAL_TIM_PWM_Start (&htim1,TIM_CHANNEL_1);//开启四路pwm波
	HAL_TIMEx_PWMN_Start (&htim1,TIM_CHANNEL_1);

(2)回调函数

在主函数外侧定义中断回调

/* USER CODE BEGIN PM */
uint16_t spwmcnt=0;//数组计数值：0~399；
float M=0.8;//调制比M：0~1

int spwm_group[400]={
	33,99,165,231,297,362,428,494,559,624,690,755,819,884,948,1013,1076,
1140,1203,1266,1329,1392,1454,1515,1577,1638,1698,1758,1818,1877,1936,1994,2052,
2110,2166,2223,2278,2333,2388,2442,2495,2548,2600,2652,2703,2753,2802,2851,2899,
2946,2993,3039,3084,3129,3172,3215,3257,3298,3339,3378,3417,3455,3492,3528,3564,
3598,3632,3664,3696,3727,3757,3786,3814,3841,3868,3893,3917,3940,3963,3984,4005,
4024,4042,4060,4076,4092,4106,4119,4132,4143,4153,4163,4171,4178,4184,4190,4194,
4197,4199,4200,4200,4199,4197,4194,4190,4184,4178,4171,4163,4153,4143,4132,4119,
4106,4092,4076,4060,4042,4024,4005,3984,3963,3940,3917,3893,3868,3841,3814,3786,
3757,3727,3696,3664,3632,3598,3564,3528,3492,3455,3417,3378,3339,3298,3257,3215,
3172,3129,3084,3039,2993,2946,2899,2851,2802,2753,2703,2652,2600,2548,2495,2442,
2388,2333,2278,2223,2166,2110,2052,1994,1936,1877,1818,1758,1698,1638,1577,1515,
1454,1392,1329,1266,1203,1140,1076,1013,948,884,819,755,690,624,559,494,
428,362,297,231,165,99,33,-33,-99,-165,-231,-297,-362,-428,-494,-559,
-624,-690,-755,-819,-884,-948,-1013,-1076,-1140,-1203,-1266,-1329,-1392,-1454,-1515,-1577,
-1638,-1698,-1758,-1818,-1877,-1936,-1994,-2052,-2110,-2166,-2223,-2278,-2333,-2388,-2442,-2495,
-2548,-2600,-2652,-2703,-2753,-2802,-2851,-2899,-2946,-2993,-3039,-3084,-3129,-3172,-3215,-3257,
-3298,-3339,-3378,-3417,-3455,-3492,-3528,-3564,-3598,-3632,-3664,-3696,-3727,-3757,-3786,-3814,
-3841,-3868,-3893,-3917,-3940,-3963,-3984,-4005,-4024,-4042,-4060,-4076,-4092,-4106,-4119,-4132,
-4143,-4153,-4163,-4171,-4178,-4184,-4190,-4194,-4197,-4199,-4200,-4200,-4199,-4197,-4194,-4190,
-4184,-4178,-4171,-4163,-4153,-4143,-4132,-4119,-4106,-4092,-4076,-4060,-4042,-4024,-4005,-3984,
-3963,-3940,-3917,-3893,-3868,-3841,-3814,-3786,-3757,-3727,-3696,-3664,-3632,-3598,-3564,-3528,
-3492,-3455,-3417,-3378,-3339,-3298,-3257,-3215,-3172,-3129,-3084,-3039,-2993,-2946,-2899,-2851,
-2802,-2753,-2703,-2652,-2600,-2548,-2495,-2442,-2388,-2333,-2278,-2223,-2166,-2110,-2052,-1994,
-1936,-1877,-1818,-1758,-1698,-1638,-1577,-1515,-1454,-1392,-1329,-1266,-1203,-1140,-1076,-1013,
-948,-884,-819,-755,-690,-624,-559,-494,-428,-362,-297,-231,-165,-99,-33,
};
 void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)  //中断回调函数 20k
{
	if(htim==&htim2)
	{
		
	__HAL_TIM_SET_COMPARE(&htim1, TIM_CHANNEL_1, (4200.f + M*spwm_group[spwmcnt]) / 2.0f);//频率算错了，20kHz频率改变200次20000 / 200 = 100Hz的正弦波，因此占空比整体除2
	spwmcnt++;
  if(spwmcnt==400)spwmcnt=0;	
  }
}
/* USER CODE END PM */

(3)验证

先关闭中断，设定一个固定比较值，用示波器观察PWM波周期是否符合要求，确认无误后，可进行后续步骤

在CubeMX中将TIM2的中断选项取消勾选再生成代码

I 验证的代码部分

在主循环外侧写入以下内容：

	__HAL_TIM_SET_COMPARE(&htim1, TIM_CHANNEL_1, 1000);//设置固定比较值为1000
  /* USER CODE END 2 */

II 示波器采样结果

PWM通道
PWM互补通道

3、滤波电路

在完成验证后，可重新开启中断，并删除验证部分代码

(1)计算规格

已知方波频率为20kHz，所以RC滤波电路的截止频率\(f_c\)应该为10kHz ~ 2kHz
根据\(f_c = \frac{1}{2\pi \times R \times C}\)以及手头得器件进行选择

由于我实验室没有合适的零件，所以选择2个10Ω的电阻串联等效，1个2.2\(\mu F\)的电容和1个1.0\(\mu F\)的电容并联等效

由公式得，截止频率为\(f_c = \frac{1}{2\pi \times 10 \Omega \times 2 \times (2.2 \mu + 1.0 \mu)} = 2,486.79 Hz\)

(2) 搭建滤波电路

依照下图进行搭建，电阻侧接信号源，电容接地

3、测试信号

将示波器鳄鱼夹处夹在电容接地端，笔头接入电容与电阻之间，便能看到正弦波信号
分别测量PWM输出通道和PWM互补通道得滤波信号，可得到一对互补的正弦波信号

4、注意事项

电容

如果是使用的点解电容，请注意电容极性与电流方向匹配

采样接地端

请注意将示波器表笔的接地端直接接在电容接地端，若接入开发板的接地端可能会受到其他信号的干扰

接入开发板总地线的效果，可见干扰明显增大

死区

注意将TIM模块设置为"生成互补PWM"模式时，要开启死区保护电路，防止短路

5、代码清单

main.c

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2025 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "tim.h"
#include "gpio.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */

/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
uint16_t spwmcnt=0;//数组计数值：0~399；
float M=0.8;//调制比M：0~1

int spwm_group[400]={
	33,99,165,231,297,362,428,494,559,624,690,755,819,884,948,1013,1076,
1140,1203,1266,1329,1392,1454,1515,1577,1638,1698,1758,1818,1877,1936,1994,2052,
2110,2166,2223,2278,2333,2388,2442,2495,2548,2600,2652,2703,2753,2802,2851,2899,
2946,2993,3039,3084,3129,3172,3215,3257,3298,3339,3378,3417,3455,3492,3528,3564,
3598,3632,3664,3696,3727,3757,3786,3814,3841,3868,3893,3917,3940,3963,3984,4005,
4024,4042,4060,4076,4092,4106,4119,4132,4143,4153,4163,4171,4178,4184,4190,4194,
4197,4199,4200,4200,4199,4197,4194,4190,4184,4178,4171,4163,4153,4143,4132,4119,
4106,4092,4076,4060,4042,4024,4005,3984,3963,3940,3917,3893,3868,3841,3814,3786,
3757,3727,3696,3664,3632,3598,3564,3528,3492,3455,3417,3378,3339,3298,3257,3215,
3172,3129,3084,3039,2993,2946,2899,2851,2802,2753,2703,2652,2600,2548,2495,2442,
2388,2333,2278,2223,2166,2110,2052,1994,1936,1877,1818,1758,1698,1638,1577,1515,
1454,1392,1329,1266,1203,1140,1076,1013,948,884,819,755,690,624,559,494,
428,362,297,231,165,99,33,-33,-99,-165,-231,-297,-362,-428,-494,-559,
-624,-690,-755,-819,-884,-948,-1013,-1076,-1140,-1203,-1266,-1329,-1392,-1454,-1515,-1577,
-1638,-1698,-1758,-1818,-1877,-1936,-1994,-2052,-2110,-2166,-2223,-2278,-2333,-2388,-2442,-2495,
-2548,-2600,-2652,-2703,-2753,-2802,-2851,-2899,-2946,-2993,-3039,-3084,-3129,-3172,-3215,-3257,
-3298,-3339,-3378,-3417,-3455,-3492,-3528,-3564,-3598,-3632,-3664,-3696,-3727,-3757,-3786,-3814,
-3841,-3868,-3893,-3917,-3940,-3963,-3984,-4005,-4024,-4042,-4060,-4076,-4092,-4106,-4119,-4132,
-4143,-4153,-4163,-4171,-4178,-4184,-4190,-4194,-4197,-4199,-4200,-4200,-4199,-4197,-4194,-4190,
-4184,-4178,-4171,-4163,-4153,-4143,-4132,-4119,-4106,-4092,-4076,-4060,-4042,-4024,-4005,-3984,
-3963,-3940,-3917,-3893,-3868,-3841,-3814,-3786,-3757,-3727,-3696,-3664,-3632,-3598,-3564,-3528,
-3492,-3455,-3417,-3378,-3339,-3298,-3257,-3215,-3172,-3129,-3084,-3039,-2993,-2946,-2899,-2851,
-2802,-2753,-2703,-2652,-2600,-2548,-2495,-2442,-2388,-2333,-2278,-2223,-2166,-2110,-2052,-1994,
-1936,-1877,-1818,-1758,-1698,-1638,-1577,-1515,-1454,-1392,-1329,-1266,-1203,-1140,-1076,-1013,
-948,-884,-819,-755,-690,-624,-559,-494,-428,-362,-297,-231,-165,-99,-33,
};
 void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)  //中断回调函数 20k
{
	if(htim==&htim2)
	{
		
//	TIM1->CCR1 = (4200.f + M*spwm_group[spwmcnt]) / 2.0f ;//20khz的频率改变400次，20000/400=50hz的正弦波；
	__HAL_TIM_SET_COMPARE(&htim1, TIM_CHANNEL_1, (4200.f + M*spwm_group[spwmcnt]) / 2.0f);
	spwmcnt++;
  if(spwmcnt==400)spwmcnt=0;	
  }
}
/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/

/* USER CODE BEGIN PV */

/* 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_TIM1_Init();
  MX_TIM2_Init();
  /* USER CODE BEGIN 2 */
	HAL_TIM_Base_Start_IT(&htim2);//开启定时器2中断
	HAL_TIM_PWM_Start (&htim1,TIM_CHANNEL_1);//开启四路pwm波
	HAL_TIMEx_PWMN_Start (&htim1,TIM_CHANNEL_1);
//	__HAL_TIM_SET_COMPARE(&htim1, TIM_CHANNEL_1, 1000);
  /* 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_SCALE2);

  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  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 = 336;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
  RCC_OscInitStruct.PLL.PLLQ = 7;
  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_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
  {
    Error_Handler();
  }
}

/* USER CODE BEGIN 4 */

/* 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 */

posted @ 2025-10-14 21:17 奶龙大王阅读(28) 评论(0) 收藏举报

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奶龙科技

技术奶龙拯救世界 Tech Nailongs Save the World

利用脉冲位宽调制技术和一级滤波电路实现正弦波输出

流程图

1、初始化硬件

(1)时钟

(2)PWM

(3)TIM

(4)代码部分

2、写入代码

(1)启用`TIM`

(2)回调函数

(3)验证

I 验证的代码部分

II 示波器采样结果

3、滤波电路

(1)计算规格

(2) 搭建滤波电路

3、测试信号

4、注意事项

电容

采样接地端

死区

5、代码清单

公告

奶龙科技

技术奶龙拯救世界 Tech Nailongs Save the World

利用脉冲位宽调制技术和一级滤波电路实现正弦波输出

流程图

1、初始化硬件

(1)时钟

(2)PWM

(3)TIM

(4)代码部分

2、写入代码

(1)启用TIM

(2)回调函数

(3)验证

I 验证的代码部分

II 示波器采样结果

3、滤波电路

(1)计算规格

(2) 搭建滤波电路

3、测试信号

4、注意事项

电容

采样接地端

死区

5、代码清单

公告

(1)启用`TIM`