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：$CNT=N\ast (ARR+1)+CRR1$
• • 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：$f=Fosc/(psc+1)$
• • Fosc:定时器的频率（主时钟频率）
• • psc：分频系数
• 📐计一个数时间：$T=1÷f$ =$\frac{1}{f}$
• 📏CNT总计数时间：$CNT\times T$
• 📏脉宽宽度等于上升沿开始到下一个下降沿之间的计数值:$CCR2\ast \frac{1}{f}$

📑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：$1/CNT\ast T=1/CNT\ast (1/f)=f/CNT$
• 🌿PWM占空比：$CRR2÷CNT$

📐最小捕获频率计算

• 🎋定时器频率: $f/psc$

• 🖍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=$f/(psc-1)$

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

• 👉🏻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 = $2000000÷N\ast (ARR+1)+CRR1$ （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=1KHzTIM2->PSC = 36 - 1; //预分频；f=2MHzHAL_TIM_IC_Start(&htim2, TIM_CHANNEL_1); //开启输入捕获上升沿：PA0HAL_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; //捕获上升沿开始计数，计数值Duty_High = TIM2->CCR2 + 1; //捕获下降沿，计数值//f = f/psc=1000 000//计一个数的时间T：1/f//PWM_f  = ARR/fPWM_f = 2000/ARR;//KHz, 1/ARR*(T)= 1/ARR*(1/f)= f/ARRDuty = 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