输入捕获实验代码2
141.5.13 输入捕获实验代码（二）
/* ========================================================================
* Project: CubeIDE/08IC
* File: Core/Inc/main.h
* ======================================================================== */
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.h
* @brief : Header for main.c file.
* This file contains the common defines of the application.
******************************************************************************
* @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 */
/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef __MAIN_H
#define __MAIN_H
#ifdef __cplusplus
extern "C" {
#endif
/* Includes ------------------------------------------------------------------*/
#include "stm32f1xx_hal.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* Exported types ------------------------------------------------------------*/
/* USER CODE BEGIN ET */
/* USER CODE END ET */
/* Exported constants --------------------------------------------------------*/
/* USER CODE BEGIN EC */
/* USER CODE END EC */
/* Exported macro ------------------------------------------------------------*/
/* USER CODE BEGIN EM */
/* USER CODE END EM */
/* Exported functions prototypes ---------------------------------------------*/
void Error_Handler(void);
/* USER CODE BEGIN EFP */
/* USER CODE END EFP */
/* Private defines -----------------------------------------------------------*/
/* USER CODE BEGIN Private defines */
/* USER CODE END Private defines */
#ifdef __cplusplus
}
#endif
#endif /* __MAIN_H */
/* ========================================================================
* Project: CubeIDE/08IC
* File: Core/Inc/gpio.h
* ======================================================================== */
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file gpio.h
* @brief This file contains all the function prototypes for
* the gpio.c file
******************************************************************************
* @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 */
/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef __GPIO_H__
#define __GPIO_H__
#ifdef __cplusplus
extern "C" {
#endif
/* Includes ------------------------------------------------------------------*/
#include "main.h"
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* USER CODE BEGIN Private defines */
/* USER CODE END Private defines */
void MX_GPIO_Init(void);
/* USER CODE BEGIN Prototypes */
/* USER CODE END Prototypes */
#ifdef __cplusplus
}
#endif
#endif /*__ GPIO_H__ */
/* ========================================================================
* Project: CubeIDE/08IC
* File: Core/Inc/tim.h
* ======================================================================== */
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file tim.h
* @brief This file contains all the function prototypes for
* the tim.c file
******************************************************************************
* @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 */
/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef __TIM_H__
#define __TIM_H__
#ifdef __cplusplus
extern "C" {
#endif
/* Includes ------------------------------------------------------------------*/
#include "main.h"
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
extern TIM_HandleTypeDef htim2;
/* USER CODE BEGIN Private defines */
/* USER CODE END Private defines */
void MX_TIM2_Init(void);
/* USER CODE BEGIN Prototypes */
/* USER CODE END Prototypes */
#ifdef __cplusplus
}
#endif
#endif /* __TIM_H__ */
/* ========================================================================
* Project: CubeIDE/08IC
* File: Core/Inc/usart.h
* ======================================================================== */
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file usart.h
* @brief This file contains all the function prototypes for
* the usart.c file
******************************************************************************
* @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 */
/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef __USART_H__
#define __USART_H__
#ifdef __cplusplus
extern "C" {
#endif
/* Includes ------------------------------------------------------------------*/
#include "main.h"
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
extern UART_HandleTypeDef huart1;
/* USER CODE BEGIN Private defines */
extern uint8_t u_buf[256];//printf?????
#define printf(...) HAL_UART_Transmit(&huart1, (uint8_t *)u_buf, sprintf((char*)u_buf, __VA_ARGS__), 0xffff)
/* USER CODE END Private defines */
void MX_USART1_UART_Init(void);
/* USER CODE BEGIN Prototypes */
/* USER CODE END Prototypes */
#ifdef __cplusplus
}
#endif
#endif /* __USART_H__ */
/* ========================================================================
* Project: CubeIDE/08IC
* File: Core/Inc/stm32f1xx_it.h
* ======================================================================== */
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file stm32f1xx_it.h
* @brief This file contains the headers of the interrupt handlers.
******************************************************************************
* @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 */
/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef __STM32F1xx_IT_H
#define __STM32F1xx_IT_H
#ifdef __cplusplus
extern "C" {
#endif
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* Exported types ------------------------------------------------------------*/
/* USER CODE BEGIN ET */
/* USER CODE END ET */
/* Exported constants --------------------------------------------------------*/
/* USER CODE BEGIN EC */
/* USER CODE END EC */
/* Exported macro ------------------------------------------------------------*/
/* USER CODE BEGIN EM */
/* USER CODE END EM */
/* Exported functions prototypes ---------------------------------------------*/
void NMI_Handler(void);
void HardFault_Handler(void);
void MemManage_Handler(void);
void BusFault_Handler(void);
void UsageFault_Handler(void);
void SVC_Handler(void);
void DebugMon_Handler(void);
void PendSV_Handler(void);
void SysTick_Handler(void);
void TIM2_IRQHandler(void);
/* USER CODE BEGIN EFP */
/* USER CODE END EFP */
#ifdef __cplusplus
}
#endif
#endif /* __STM32F1xx_IT_H */
/* ========================================================================
* Project: CubeIDE/08IC
* File: Core/Src/main.c
* ======================================================================== */
/* 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 */
/* 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 */
uint32_t ic_state=0,period_count=0,ic_count=0,us_count;
/* 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_TIM2_Init();
MX_USART1_UART_Init();
/* USER CODE BEGIN 2 */
HAL_TIM_Base_Start_IT(&htim2);
HAL_TIM_IC_Start_IT(&htim2, TIM_CHANNEL_2);
printf("Please connect MCU51 P2.0,and let SG90 run to detect signal!\n");
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
if(ic_state== 2 )
{
us_count = ic_count + period_count * 0xFFFF;
printf("High level duration: %ldus \n",us_count);//(float)(us_count)/1000.000
ic_state = 0;
}
/* 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};
/** 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 */
void HAL_TIM_IC_CaptureCallback(TIM_HandleTypeDef *htim)
{
if(TIM2 == htim->Instance)
{
if ( ic_state == 0 )
{
__HAL_TIM_SET_COUNTER(htim,0);
__HAL_TIM_SET_CAPTUREPOLARITY(&htim2, TIM_CHANNEL_2, TIM_INPUTCHANNELPOLARITY_FALLING);
ic_state = 1;
period_count = 0;
ic_count = 0;
}
else
{
ic_count = HAL_TIM_ReadCapturedValue(&htim2,TIM_CHANNEL_2);
__HAL_TIM_SET_CAPTUREPOLARITY(&htim2, TIM_CHANNEL_2, TIM_INPUTCHANNELPOLARITY_RISING);
ic_state = 2;
}
}
}
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
if(TIM2 == htim->Instance){
if(ic_state==1)
{
if(period_count==0XFFFF)
{
ic_state=2;
ic_count=0XFFFF;
}else period_count++;
}
}
}
/* 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 */
/* ========================================================================
* Project: CubeIDE/08IC
* File: Core/Src/gpio.c
* ======================================================================== */
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file gpio.c
* @brief This file provides code for the configuration
* of all used GPIO pins.
******************************************************************************
* @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 "gpio.h"
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/*----------------------------------------------------------------------------*/
/* Configure GPIO */
/*----------------------------------------------------------------------------*/
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/** Configure pins as
* Analog
* Input
* Output
* EVENT_OUT
* EXTI
*/
void MX_GPIO_Init(void)
{
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOA_CLK_ENABLE();
}
/* USER CODE BEGIN 2 */
/* USER CODE END 2 */
/* ========================================================================
* Project: CubeIDE/08IC
* File: Core/Src/tim.c
* ======================================================================== */
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file tim.c
* @brief This file provides code for the configuration
* of the TIM instances.
******************************************************************************
* @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 "tim.h"
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
TIM_HandleTypeDef htim2;
/* TIM2 init function */
void MX_TIM2_Init(void)
{
/* USER CODE BEGIN TIM2_Init 0 */
/* USER CODE END TIM2_Init 0 */
TIM_ClockConfigTypeDef sClockSourceConfig = {0};
TIM_MasterConfigTypeDef sMasterConfig = {0};
TIM_IC_InitTypeDef sConfigIC = {0};
/* USER CODE BEGIN TIM2_Init 1 */
/* USER CODE END TIM2_Init 1 */
htim2.Instance = TIM2;
htim2.Init.Prescaler = 71;
htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
htim2.Init.Period = 0xffff;
htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
htim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;
if (HAL_TIM_Base_Init(&htim2) != HAL_OK)
{
Error_Handler();
}
sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
if (HAL_TIM_ConfigClockSource(&htim2, &sClockSourceConfig) != HAL_OK)
{
Error_Handler();
}
if (HAL_TIM_IC_Init(&htim2) != HAL_OK)
{
Error_Handler();
}
sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
if (HAL_TIMEx_MasterConfigSynchronization(&htim2, &sMasterConfig) != HAL_OK)
{
Error_Handler();
}
sConfigIC.ICPolarity = TIM_INPUTCHANNELPOLARITY_RISING;
sConfigIC.ICSelection = TIM_ICSELECTION_DIRECTTI;
sConfigIC.ICPrescaler = TIM_ICPSC_DIV1;
sConfigIC.ICFilter = 0;
if (HAL_TIM_IC_ConfigChannel(&htim2, &sConfigIC, TIM_CHANNEL_2) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN TIM2_Init 2 */
/* USER CODE END TIM2_Init 2 */
}
void HAL_TIM_Base_MspInit(TIM_HandleTypeDef* tim_baseHandle)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
if(tim_baseHandle->Instance==TIM2)
{
/* USER CODE BEGIN TIM2_MspInit 0 */
/* USER CODE END TIM2_MspInit 0 */
/* TIM2 clock enable */
__HAL_RCC_TIM2_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
/**TIM2 GPIO Configuration
PA1 ------> TIM2_CH2
*/
GPIO_InitStruct.Pin = GPIO_PIN_1;
GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
GPIO_InitStruct.Pull = GPIO_PULLUP;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/* TIM2 interrupt Init */
HAL_NVIC_SetPriority(TIM2_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(TIM2_IRQn);
/* USER CODE BEGIN TIM2_MspInit 1 */
/* USER CODE END TIM2_MspInit 1 */
}
}
void HAL_TIM_Base_MspDeInit(TIM_HandleTypeDef* tim_baseHandle)
{
if(tim_baseHandle->Instance==TIM2)
{
/* USER CODE BEGIN TIM2_MspDeInit 0 */
/* USER CODE END TIM2_MspDeInit 0 */
/* Peripheral clock disable */
__HAL_RCC_TIM2_CLK_DISABLE();
/**TIM2 GPIO Configuration
PA1 ------> TIM2_CH2
*/
HAL_GPIO_DeInit(GPIOA, GPIO_PIN_1);
/* TIM2 interrupt Deinit */
HAL_NVIC_DisableIRQ(TIM2_IRQn);
/* USER CODE BEGIN TIM2_MspDeInit 1 */
/* USER CODE END TIM2_MspDeInit 1 */
}
}
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* ========================================================================
* Project: CubeIDE/08IC
* File: Core/Src/usart.c
* ======================================================================== */
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file usart.c
* @brief This file provides code for the configuration
* of the USART instances.
******************************************************************************
* @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 "usart.h"
/* USER CODE BEGIN 0 */
uint8_t u_buf[256];
/* USER CODE END 0 */
UART_HandleTypeDef huart1;
/* USART1 init function */
void MX_USART1_UART_Init(void)
{
/* USER CODE BEGIN USART1_Init 0 */
/* USER CODE END USART1_Init 0 */
/* USER CODE BEGIN USART1_Init 1 */
/* USER CODE END USART1_Init 1 */
huart1.Instance = USART1;
huart1.Init.BaudRate = 115200;
huart1.Init.WordLength = UART_WORDLENGTH_8B;
huart1.Init.StopBits = UART_STOPBITS_1;
huart1.Init.Parity = UART_PARITY_NONE;
huart1.Init.Mode = UART_MODE_TX_RX;
huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
huart1.Init.OverSampling = UART_OVERSAMPLING_16;
if (HAL_UART_Init(&huart1) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN USART1_Init 2 */
/* USER CODE END USART1_Init 2 */
}
void HAL_UART_MspInit(UART_HandleTypeDef* uartHandle)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
if(uartHandle->Instance==USART1)
{
/* USER CODE BEGIN USART1_MspInit 0 */
/* USER CODE END USART1_MspInit 0 */
/* USART1 clock enable */
__HAL_RCC_USART1_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
/**USART1 GPIO Configuration
PA9 ------> USART1_TX
PA10 ------> USART1_RX
*/
GPIO_InitStruct.Pin = GPIO_PIN_9;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
GPIO_InitStruct.Pin = GPIO_PIN_10;
GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/* USER CODE BEGIN USART1_MspInit 1 */
/* USER CODE END USART1_MspInit 1 */
}
}
void HAL_UART_MspDeInit(UART_HandleTypeDef* uartHandle)
{
if(uartHandle->Instance==USART1)
{
/* USER CODE BEGIN USART1_MspDeInit 0 */
/* USER CODE END USART1_MspDeInit 0 */
/* Peripheral clock disable */
__HAL_RCC_USART1_CLK_DISABLE();
/**USART1 GPIO Configuration
PA9 ------> USART1_TX
PA10 ------> USART1_RX
*/
HAL_GPIO_DeInit(GPIOA, GPIO_PIN_9|GPIO_PIN_10);
/* USER CODE BEGIN USART1_MspDeInit 1 */
/* USER CODE END USART1_MspDeInit 1 */
}
}
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* ========================================================================
* Project: CubeIDE/08IC
* File: Core/Src/stm32f1xx_it.c
* ======================================================================== */
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file stm32f1xx_it.c
* @brief Interrupt Service Routines.
******************************************************************************
* @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 "stm32f1xx_it.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN TD */
/* USER CODE END TD */
/* 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 -----------------------------------------------*/
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/* External variables --------------------------------------------------------*/
extern TIM_HandleTypeDef htim2;
/* USER CODE BEGIN EV */
/* USER CODE END EV */
/******************************************************************************/
/* Cortex-M3 Processor Interruption and Exception Handlers */
/******************************************************************************/
/**
* @brief This function handles Non maskable interrupt.
*/
void NMI_Handler(void)
{
/* USER CODE BEGIN NonMaskableInt_IRQn 0 */
/* USER CODE END NonMaskableInt_IRQn 0 */
/* USER CODE BEGIN NonMaskableInt_IRQn 1 */
while (1)
{
}
/* USER CODE END NonMaskableInt_IRQn 1 */
}
/**
* @brief This function handles Hard fault interrupt.
*/
void HardFault_Handler(void)
{
/* USER CODE BEGIN HardFault_IRQn 0 */
/* USER CODE END HardFault_IRQn 0 */
while (1)
{
/* USER CODE BEGIN W1_HardFault_IRQn 0 */
/* USER CODE END W1_HardFault_IRQn 0 */
}
}
/**
* @brief This function handles Memory management fault.
*/
void MemManage_Handler(void)
{
/* USER CODE BEGIN MemoryManagement_IRQn 0 */
/* USER CODE END MemoryManagement_IRQn 0 */
while (1)
{
/* USER CODE BEGIN W1_MemoryManagement_IRQn 0 */
/* USER CODE END W1_MemoryManagement_IRQn 0 */
}
}
/**
* @brief This function handles Prefetch fault, memory access fault.
*/
void BusFault_Handler(void)
{
/* USER CODE BEGIN BusFault_IRQn 0 */
/* USER CODE END BusFault_IRQn 0 */
while (1)
{
/* USER CODE BEGIN W1_BusFault_IRQn 0 */
/* USER CODE END W1_BusFault_IRQn 0 */
}
}
/**
* @brief This function handles Undefined instruction or illegal state.
*/
void UsageFault_Handler(void)
{
/* USER CODE BEGIN UsageFault_IRQn 0 */
/* USER CODE END UsageFault_IRQn 0 */
while (1)
{
/* USER CODE BEGIN W1_UsageFault_IRQn 0 */
/* USER CODE END W1_UsageFault_IRQn 0 */
}
}
/**
* @brief This function handles System service call via SWI instruction.
*/
void SVC_Handler(void)
{
/* USER CODE BEGIN SVCall_IRQn 0 */
/* USER CODE END SVCall_IRQn 0 */
/* USER CODE BEGIN SVCall_IRQn 1 */
/* USER CODE END SVCall_IRQn 1 */
}
/**
* @brief This function handles Debug monitor.
*/
void DebugMon_Handler(void)
{
/* USER CODE BEGIN DebugMonitor_IRQn 0 */
/* USER CODE END DebugMonitor_IRQn 0 */
/* USER CODE BEGIN DebugMonitor_IRQn 1 */
/* USER CODE END DebugMonitor_IRQn 1 */
}
/**
* @brief This function handles Pendable request for system service.
*/
void PendSV_Handler(void)
{
/* USER CODE BEGIN PendSV_IRQn 0 */
/* USER CODE END PendSV_IRQn 0 */
/* USER CODE BEGIN PendSV_IRQn 1 */
/* USER CODE END PendSV_IRQn 1 */
}
/**
* @brief This function handles System tick timer.
*/
void SysTick_Handler(void)
{
/* USER CODE BEGIN SysTick_IRQn 0 */
/* USER CODE END SysTick_IRQn 0 */
HAL_IncTick();
/* USER CODE BEGIN SysTick_IRQn 1 */
/* USER CODE END SysTick_IRQn 1 */
}
/******************************************************************************/
/* STM32F1xx Peripheral Interrupt Handlers */
/* Add here the Interrupt Handlers for the used peripherals. */
/* For the available peripheral interrupt handler names, */
/* please refer to the startup file (startup_stm32f1xx.s). */
/******************************************************************************/
/**
* @brief This function handles TIM2 global interrupt.
*/
void TIM2_IRQHandler(void)
{
/* USER CODE BEGIN TIM2_IRQn 0 */
/* USER CODE END TIM2_IRQn 0 */
HAL_TIM_IRQHandler(&htim2);
/* USER CODE BEGIN TIM2_IRQn 1 */
/* USER CODE END TIM2_IRQn 1 */
}
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
一、输入捕获实验代码分析
1.1 代码分析
下降沿到达时，硬件已经把当时的 CNT 锁存在 CCR2。HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_2) 读取的是这个锁存值，不是读取函数执行瞬间的 CNT，因此中断响应延迟通常不会直接增加测量脉宽。
若测量期间 CNT 没有溢出，捕获值就是从上升沿清零到下降沿的计数数。若发生溢出，正确公式是：
总计数 = 溢出次数 × (ARR + 1) + 最后一次CCR2
总时间 = 总计数 × 单个计数时间
本实验 ARR=0xFFFF、每格 1 μs，所以：
us_count = period_count × 0x10000 + ic_count
工程代码使用了 period_count * 0xFFFF，每次溢出会少算 1 μs；应使用 0x10000，或者写成更通用的 (uint32_t)(__HAL_TIM_GET_AUTORELOAD(&htim2) + 1U)。
建议参与计算的变量至少使用 32 位：
volatile uint8_t ic_state;
volatile uint32_t period_count;
volatile uint32_t ic_count;
uint64_t total_ticks;
total_ticks =
(uint64_t)period_count *
((uint64_t)__HAL_TIM_GET_AUTORELOAD(&htim2) + 1ULL) +
ic_count;
使用 64 位中间量可避免长脉宽时 32 位乘加溢出。若只测 0.5～2.5 ms 舵机脉冲，CNT 不会在 65.536 ms 内溢出，period_count 正常应为 0。
主循环打印完成后把 ic_state 恢复为 0。为避免中断在主循环读取多个共享变量时恰好改写它们，可以在极短的临界区内复制一份快照，再开放中断并完成格式化、串口发送。
1.2 定时器中断回调函数分析
这里分析的是定时器周期回调函数 HAL_TIM_PeriodElapsedCallback()。它由更新事件触发，用于记录计数器回绕：
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
if ((htim->Instance == TIM2) && (ic_state == 1U)) {
period_count++;
}
}
必须同时判断 htim->Instance == TIM2，因为 HAL 的周期回调可能被多个定时器共用；还要只在状态 1 累计，避免等待上升沿或处理结果时误计。
TIM2 的更新事件和 CH2 捕获事件共用同一个 TIM2_IRQHandler()，但它们是两类独立事件。HAL_TIM_Base_Start_IT() 使能更新中断，用来累计 period_count；HAL_TIM_IC_Start_IT() 使能捕获中断，用来切换边沿并读取 CCR2。二者都启动后，TIM2_IRQHandler() 再将挂起标志交给 HAL_TIM_IRQHandler() 分发到对应回调。缺少其中任意一个启动调用，测量范围或边沿处理都会不完整。
相关中断路径为：
flowchart TD
A[TIM2事件] --> B{事件类型}
B -->|CH2边沿| C[SR.CC2IF]
B -->|CNT溢出| D[SR.UIF]
C --> E[HAL_TIM_IRQHandler]
D --> E
E --> F[清CC2IF]
F --> G[HAL_TIM_IC_CaptureCallback]
E --> H[清UIF]
H --> I[HAL_TIM_PeriodElapsedCallback]
当捕获边沿恰好落在计数器溢出附近时，CC2IF 与 UIF 可能同时挂起。此时“捕获发生在溢出前还是溢出后”会影响总计数，单纯依赖两个回调的执行先后可能产生一个模数的误差。可采用以下办法提高可靠性：
- 在同一中断上下文中同时读取
SR、CCR2和CNT，依据标志与计数位置判断先后； - 维护扩展时间戳，在捕获时把高位溢出计数与
CCR2原子组合； - 使用 PWM Input/从模式复位，让硬件在有效边沿自动复位计数器；
- 本实验只测小于 65.536 ms 的舵机高脉宽时，可把 ARR 设计得更大或确认不会溢出，从根本上避开边界。
CC2OF 也值得检查：它表示上一次捕获尚未及时处理，又有新边沿到来。出现该标志时，当前测量可能已经丢失边沿，不应继续把数据当作可靠结果。
工程在溢出次数过多时把状态强制置为完成并给出特殊值，这更接近超时保护。更清晰的实现应设置独立的错误码，例如“等待下降沿超时”，主循环收到后打印故障信息并重新同步到下一个上升沿，而不是把超时值伪装成正常脉宽。