输入捕获实验代码1
140.5.12输入捕获实验代码(1)
/* ========================================================================
* 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
输入捕获用于测量外部数字信号的边沿时间。TIM2_CH2 接收到选定边沿时，硬件会把当时的 CNT 锁存到 CCR2，并置位捕获标志。软件读取 CCR2，即可计算两个边沿之间的时间。
flowchart LR
P[PA1/TIM2_CH2] --> M[输入选择CC2S]
M --> F[数字滤波IC2F]
F --> E[极性检测CC2P]
E --> L[边沿到来锁存CNT]
L --> C[CCR2]
L --> S[SR.CC2IF]
S --> I[DIER.CC2IE与NVIC]
I --> H[HAL_TIM_IC_CaptureCallback]
1.1 定时器配置
TIM2 的参数为 PSC=71、ARR=0xFFFF，输入时钟为 72 MHz：
计数频率 = 72 MHz / (71+1) = 1 MHz
每个计数 = 1 μs
溢出模数 = ARR+1 = 65536
溢出周期 = 65536 μs = 65.536 ms
CH2 配置为上升沿、直接输入、每个有效边沿都捕获、数字滤波值为 0。滤波值 0 表示没有数字去抖滤波，接线较长或噪声较大时可能出现误捕获，应结合信号质量选择滤波参数。
1.2 实验演示
实验把 51 单片机舵机控制信号接到 STM32 的 PA1，由 STM32 测量高电平脉宽。接线应是：
51单片机 P2.0（信号） ───── STM32 PA1 / TIM2_CH2
51单片机 GND ───────────── STM32 GND
舵机电源按原控制系统供电，信号测量必须共地
STM32 输入只测逻辑信号，不承担舵机电流。接线前应确认信号电压满足 PA1 的电气限制；需要改线时先断电，避免信号悬空、短路或热插拔造成异常。
测得约 500、1000、1500、2000、2500 μs，分别对应舵机控制中常见的 0.5～2.5 ms 高脉宽范围。
1.3 代码分析
1.3.1 main.c文件
复位后先由启动代码建立运行环境，再调用 main()。只有启动模式选择系统存储器等特殊区域时，才会进入芯片内置 Bootloader；正常从 Flash 启动不能笼统称为先运行 Bootloader。
业务变量用于保存捕获状态、溢出次数、当前捕获值和换算后的微秒数。凡是中断和主循环共同访问的变量，都应声明为 volatile，否则编译器可能缓存数值，主循环看不到中断中的最新修改。
1.3.2 配置系统时钟
SystemClock_Config() 把系统与定时器时钟配置到实验所需频率。它是 MCU 时钟树配置，不是 ST-Link 调试器配置。计算 TIM2 时钟时还要注意 APB 分频规则：当 APB 预分频不为 1 时，许多 STM32F1 定时器内核时钟是该 APB 外设时钟的 2 倍。
1.3.3 定时器二
TIM2 既承担自由运行计数，又承担 CH2 输入捕获。与测量有关的寄存器如下：
| 寄存器/位 | 作用 |
|---|---|
PSC | 把定时器时钟分到 1 MHz |
ARR | 决定 65536 个计数后溢出 |
CNT | 当前时间计数 |
CCMR1.CC2S | 把 CH2 连接到直接输入 TI2 |
CCMR1.IC2F | 输入数字滤波 |
CCER.CC2P | 选择捕获上升沿或下降沿 |
CCR2 | 保存捕获瞬间的 CNT |
DIER.CC2IE | 允许 CH2 捕获中断 |
SR.CC2IF | CH2 已发生捕获 |
SR.CC2OF | 新捕获覆盖了未及时处理的捕获 |
1.3.4 主函数
初始化顺序是 HAL、系统时钟、GPIO、TIM2、USART1。随后主循环等待 ic_state==2，计算脉宽、串口打印，再把状态恢复为 0，等待下一次测量。
这个实现只有一个结果槽。若信号边沿很快或打印阻塞很久，下一次测量可能覆盖尚未处理的数据。舵机信号约 20 ms 一帧，演示条件下通常足够；更高频的输入应使用缓冲队列、DMA 或更短的中断路径。
1.3.5 打开定时器
工程需要同时启动更新中断和输入捕获中断：
HAL_TIM_Base_Start_IT(&htim2);
HAL_TIM_IC_Start_IT(&htim2, TIM_CHANNEL_2);
第一句使能更新中断，用于累计 CNT 溢出次数；第二句使能 CH2 捕获中断。只启动其中一个，会分别失去跨溢出测量能力或边沿捕获能力。
1.3.6 配置界面
CubeMX 中 CH2 选择 Input Capture direct mode，极性先设为 Rising Edge，预分频为 DIV1，滤波为 0；PA1 配成 TIM2_CH2 输入，并开启 TIM2 全局中断。
PA1 在该工程中使用上拉输入。上拉只能在信号源断开时提供默认电平，不能替代共地，也不能修复超过电气额定值的输入电压。
1.3.7 分析代码
软件用一次上升沿作为起点、下一次下降沿作为终点，因此测到的是高电平宽度：
状态0：等待上升沿
上升沿到达 → CNT清零，改捕获下降沿，进入状态1
状态1：累计时间
CNT溢出 → period_count加1
下降沿到达 → 读CCR2，改回上升沿，进入状态2
状态2：主循环换算并打印
完成后回到状态0
1.3.7.1 ic_state定义
| 状态值 | 含义 | 允许的下一步 |
|---|---|---|
| 0 | 等待测量起始上升沿 | 清零计数并切到下降沿 |
| 1 | 正在测量高电平 | 等下降沿，期间统计溢出 |
| 2 | 一次结果已完成 | 主循环读取、打印并复位状态 |
状态变量能避免把每个边沿都按相同方式处理。中断与主循环共享时，建议定义为 volatile uint8_t。
1.3.7.2 回调函数
上升沿回调清零 CNT、把下一次捕获极性改成下降沿，并清零溢出次数；下降沿回调读取 CCR2，再把极性切回上升沿。
if (ic_state == 0U) {
__HAL_TIM_SET_COUNTER(htim, 0U);
__HAL_TIM_SET_CAPTUREPOLARITY(htim, TIM_CHANNEL_2,
TIM_INPUTCHANNELPOLARITY_FALLING);
period_count = 0U;
ic_state = 1U;
} else if (ic_state == 1U) {
ic_count = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_2);
__HAL_TIM_SET_CAPTUREPOLARITY(htim, TIM_CHANNEL_2,
TIM_INPUTCHANNELPOLARITY_RISING);
ic_state = 2U;
}
切换极性、清状态和改状态值的顺序应尽量紧凑。如果输入在这几条语句之间再次变化，可能漏掉边沿；需要高可靠测量时可使用 PWM Input 模式、从模式复位计数器、DMA 或专门设计的双通道捕获方案。
工程中的第二个分支写成了不带条件的 else，因此主循环尚未处理状态 2 时若又来一次捕获，也会进入下降沿处理并覆盖数据。更稳妥的写法是明确使用 else if (ic_state == 1U)，状态 2 到来的边沿只记录为丢帧或直接忽略。