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1
TIM_CHANNEL_2 - 通道2
TIM_CHANNEL_3 - 通道3
TIM_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。
