本文利用前几节所学知识来实现一个呼吸灯实验：两颗led灯交替呼吸。
一、STM32CubeMX配置
step1：配置调试接口
step2：配置定时器
定时器1位于APB2总线上，如上图所示。
step3：配置时基单元
按照下图配置
时钟来源配置为内部RCC
预分频器PSC设置为7
自动重装寄存器ARR设置为999
计数方向CNT设置为上计数
重复计数器RCR设置为0
为了防止寄存器跑飞，我们使能ARR寄存器的预加载
设置完成后定时器CNT的值就会从0增加到999，而且发送一次溢出，周期为1ms
step4：输出PWM
使用定时器1的通道1向外输出PWM
Channel1参数说明：
先回顾一下上一节的八种输出比较的模式
最后是No Outout : 两种输出都禁止
CHx :只使能正常输出
CHxN ：只使能互补输出
CHx CHxN ：两种输出都使能
我们选择两种输出都使能
step5：连接电路图
step6：设置CH1的PWM参数
step7：生成代码
step8：
step9：
step10：
二、编程接口
HAL_StatusTypeDef HAL_TIM_PWM_Start(TIM_HandleTypeDef *htim ,uint32_t Channel)作用 ：启动PWM的正常输出HAL_StatusTypeDef HAL_TIMEx_PWMN_Start(TIM_HandleTypeDef *htim ,uint32_t Channel)作用 ：启动PWM的互补输出参数说明：htim 填写定时器句柄Channel ：填写通道编号 TIM_CHANNEL_1 - 通道1TIM_CHANNEL_2 - 通道2TIM_CHANNEL_3 - 通道3TIM_CHANNEL_4 - 通道4
__HAL_TIM_GET_PRESCALER(__HANDLE__) //读PSC__HAL_TIM_SET_PRESCALER(__HANDLE__ , __VAL__) //写PSC_____________________________________________________________________________________________HAL_TIM_GET_COUBTER(__HANDLE__) //读CNT__HAL_TIM_SET_COUNTER(__HANDLE__ , __VAL__) //写CNT_____________________________________________________________________________________________HAL_TIM_GET_AUTORELOAD(__HANDLE__) //读ARR__HAL_TIM_SET_AUTORELOAD(__HANDLE__ , __VAL__) //写ARR———————————————————————————————————————————————————————————————————————————————————————————__HAL_TIM_GET_COMPARE(__HANDLE__) //读CCR__HAL_TIM_SET_COMPARE(__HANDLE__ , __VAL__) //写CCR三、编程思路
公式：占空比 = 0.5sin(2Πt + 0.5)
先启动 通道1的正常输出
再启动通道1 的互补输出在while循环里面根据公式修改PWM的占空比 PWM的周期 = ARR+1占空比 = 高电压所占时间 / 总时间 = CCR / ARR+1
在while循环里面 ：
先获取当前时间
计算占空比
获取ARR寄存器的值
计算CCR寄存器的值
将结果写入CCR
四、代码
/* 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"
#include "math.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 *//* 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();/* USER CODE BEGIN 2 */HAL_TIM_PWM_Start(&htim1 , TIM_CHANNEL_1); //启动正常输出HAL_TIMEx_PWMN_Start(&htim1 , TIM_CHANNEL_1); //启动互补输出/* USER CODE END 2 *//* Infinite loop *//* USER CODE BEGIN WHILE */while (1){float t = HAL_GetTick()* 0.01 ;// 获取当前时间float duty = 0.5 * sin(2 * 3.14 * t) + 0.5 ; // 计算占空比uint16_t arr = __HAL_TIM_GET_AUTORELOAD(&htim1); //获取ARR寄存器的值uint16_t ccr =duty * (arr + 1); //计算CCR寄存器的值__HAL_TIM_SET_COMPARE(&htim1 , TIM_CHANNEL_1 , ccr); //将计算结果写入CCR/* 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_HSI;RCC_OscInitStruct.HSIState = RCC_HSI_ON;RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;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_HSI;RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != 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 */
最后将代码下载编译即可看到两颗LED灯交替闪烁。
