STM32 HAL库定时器输入捕获SlaveMode脉宽测量

STM32 HAL库定时器输入捕获SlaveMode脉宽测量

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SlaveMode模式简介

✨SlaveMode复位模式：在发生一个触发输入事件时，计数器和它的预分频器能够重新被初始化；同时，如果TIMx_CR1寄存器的URS位为低，还会产生一个更新事件UEV；然后所有的预装载寄存器(TIMx_ARR， TIMx_CCRx)都会被更新。

• 🔖当所测频率低于最小定时器捕获频率时，需要使能自动重装载和定时器溢出中断。

SlaveMode模式下当输入捕获引脚接收到脉冲的上降沿信号时，产生复位并从零开始重新计数。

• 🎋一个周期内的总计数：输入捕获上（下）升沿信号开始，到下一个上(下)升沿结束总计数个数： C N T = N ∗ ( A R R + 1 ) + C R R 1 CNT=N*(ARR+1)+CRR1 CNT=N∗(ARR+1)+CRR1
• • N:定时器溢出次数
• • ARR:TIMx预装载值
• • TIMx->CRR1寄存器计数值
• 🌴定时器计数频率： f = F o s c / ( p s c + 1 ) f =Fosc/(psc+1) f=Fosc/(psc+1)
• • Fosc:定时器的频率（主时钟频率）
• • psc：分频系数
• 📐计一个数时间： T = 1 ÷ f T = 1 \div f T=1÷f = 1 f \frac{1}f f1
• 📏CNT总计数时间： C N T × T CNT \times T CNT×T
• 📏脉宽宽度等于上升沿开始到下一个下降沿之间的计数值: C C R 2 ∗ 1 f CCR2*\frac{1}f CCR2∗f1

📑PWM主要参数

• 🌿频率：是指1秒钟内信号从高电平到低电平再回到高电平的次数(一个周期)；
• 🌿占空比：一个脉冲周期内，高电平的时间与整个周期时间的比例。

🛠输入捕获SlaveMode脉宽测量

• 🌿输入捕获到的PWM信号频率： 1 / C N T ∗ T = 1 / C N T ∗ ( 1 / f ) = f / C N T 1/CNT*T = 1/CNT*(1/f) = f/CNT 1/CNT∗T=1/CNT∗(1/f)=f/CNT
• 🌿PWM占空比： C R R 2 ÷ C N T CRR2 \div CNT CRR2÷CNT

📐最小捕获频率计算

• 🎋定时器频率: f / p s c f/psc f/psc

🖍如果STM32以72MHz主频,定时器分频系数为36，定时器的时钟频率为2MHz。

PSC定时器TIMx->PSC= f / ( p s c − 1 ) f/(psc-1) f/(psc−1)

• 🔧在没有开启溢出中断的情况下，最小捕获频率 = 2000000 ÷ 65535 ≈ 15.25 H z 2000 000 \div 65535 \approx 15.25Hz 2000000÷65535≈15.25Hz

• 👉🏻如果开启了溢出中断，那么捕获频率就不受限制。

• 🔧开启溢出中断的情况下，捕获频率 = 2000000 ÷ N ∗ ( A R R + 1 ) + C R R 1 2000 000 \div N*(ARR+1)+CRR1 2000000÷N∗(ARR+1)+CRR1 （其中N代表溢出次数，ARR代表装载值）

• 🔖如果被测量的频率低于1Hz，那么测量就没有多大意义了。

📝输入捕获SlaveMode脉宽测量例程

使用STM32F1利用TIM3通道1产生PWM输出信号，使用TIM2定时器作为信号输入捕获，并开启SlaveMode模式设置为ReSet Mode,同时开启两路极性互补输入捕获。

• 🌿接线说明：PA6 PWM输出引脚和PA0输入捕获引脚连接到一起即可进行测量。
  
• 🔨TIM2输入捕获配置

• 🌿TIM3配置输出PWM占空比和频率可以行调整测试。
  
• 📑main程序代码

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2023 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 "usart.h"
#include "gpio.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "stdio.h"
#include "string.h"
/* 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 */

/* 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 */
    uint8_t USART_TX_Buff[32] = {0};
    uint16_t Duty, Duty_High, ARR, PWM_f;
    /* 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_TIM2_Init();
    MX_TIM3_Init();
    MX_USART1_UART_Init();
    /* USER CODE BEGIN 2 */
    HAL_TIM_PWM_Start(&htim3, TIM_CHANNEL_1); //开启PWM输出通道:PA6
//			TIM3->ARR = 1000-1;//自动重装载值
    TIM3->CCR1 = 300;//捕获/比较计数值，PWM占空比5000/1000=50% f=1MHz/1000=1KHz

    TIM2->PSC = 36 - 1; //预分频；f=2MHz
    HAL_TIM_IC_Start(&htim2, TIM_CHANNEL_1); //开启输入捕获上升沿：PA0
    HAL_TIM_IC_Start(&htim2, TIM_CHANNEL_2); //开启输入捕获下降沿:PA0
    /* USER CODE END 2 */

    /* Infinite loop */
    /* USER CODE BEGIN WHILE */
    while(1)
    {
        /* USER CODE END WHILE */

        /* USER CODE BEGIN 3 */
        HAL_Delay(1000);
        ARR = TIM2->CCR1 + 1; //捕获从上一个上升沿开始到下一个上升沿结束的计数值，也就是一个完整周期的计数值
        Duty_High = TIM2->CCR2 + 1; //捕获从上一个上升沿开始到下降沿之间的计数值，也就是高电平计数值
				//f = f/psc=1000 000
				//计一个数的时间T：1/f
				//PWM_f  = ARR/f
        PWM_f = 2000/ARR;//KHz, 1/ARR*(T)= 1/ARR*(1/f)= f/ARR
        Duty = Duty_High * 100 / ARR;
        sprintf((char*)USART_TX_Buff, "PWM_f:%dKHz,ARR:%d,Duty_High:%d,Duty:%d%%", PWM_f, ARR, Duty_High, Duty); //打印输入捕获总计数值，高电平计数值
        printf("%s \n", USART_TX_Buff);
        memset((char*)USART_TX_Buff, '\0', strlen((char*)USART_TX_Buff)); //清空数组
    }
    /* USER CODE END 3 */
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
    RCC_OscInitTypeDef RCC_OscInitStruct = {0};
    RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

    /** 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.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
    RCC_OscInitStruct.HSIState = RCC_HSI_ON;
    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
    RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
    RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
    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 */

• 📋串口打印
  

📚工程源码

链接：https://pan.baidu.com/s/1OJ6JuZt-76A-AjvvB2H3cA 
提取码：p4hf