stm32 PWM实现呼吸灯

• 项目：stm32 输出PWM实现呼吸灯效果
• 代码：
  • PWM.c

    #include "stm32f10x.h"
    
    
    void PWM_Init(void)
    {
    	//PB0默认TIM3_CH3通道
    	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
    	
    	//配置PB0为复用推挽输出
    	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
    	GPIO_InitTypeDef GPIO_InitStructure;
    	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;		//复用推挽输出，中断控制来自片上外设（TIM3_CH3），而非输出数据寄存器
    	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
    	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    	GPIO_Init(GPIOB, &GPIO_InitStructure);
    	//设置TIM3定时器内部时钟源
    	TIM_InternalClockConfig(TIM3);
    	//频率为1kHz, 占空比为50%，分辨率为1%
    	TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
    	TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    	TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
    	TIM_TimeBaseInitStructure.TIM_Period = 100 - 1;		//ARR
    	TIM_TimeBaseInitStructure.TIM_Prescaler = 720 - 1;		//PSC
    	TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;
    	TIM_TimeBaseInit(TIM3, &TIM_TimeBaseInitStructure);
    	//清除更新标志位
    	TIM_ClearFlag(TIM3, TIM_FLAG_Update);
    	TIM_ITConfig(TIM3, TIM_IT_Update, ENABLE);	//TIM3中断配置使能
    	
    	TIM_OCInitTypeDef	TIM_OCInitStructure;
    	TIM_OCStructInit(&TIM_OCInitStructure);		//给结构体赋初始值
    	TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;		//输出比较模式
    	TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;	//极性选择
    	TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;	//输出使能
    	TIM_OCInitStructure.TIM_Pulse = 0;		//CCR
    	TIM_OC3Init(TIM3, &TIM_OCInitStructure);
    	//打开TIM3定时器外设
    	TIM_Cmd(TIM3, ENABLE);
    	
    }
    
    
    //PWM占空比的函数
    void PWM_SetCompare3(uint16_t Compare3)
    {
    	TIM_SetCompare3(TIM3, Compare3);
    }
    

    　　

  • PWM.h

    #ifndef __PWM_H
    #define __PWM_H
    void PWM_Init(void);
    void PWM_SetCompare3(uint16_t Compare3);
    
    #endif
    

    　　

  • main.c

    #include "stm32f10x.h"
    #include "Delay.h"
    #include "OLED.h"
    #include "PWM.h"
    
    uint8_t i;
    
    int main(void)
    {
    	PWM_Init();		//PWM初始化
    	
    	while(1)	
    	{	
    		for(i = 0; i <= 100; i ++)
    		{
    			PWM_SetCompare3(i);		//设置TIM3捕获比较3寄存器的值，即CRR
    			Delay_ms(10);
    		}
    		for(i = 0; i <= 100; i ++)
    		{
    			PWM_SetCompare3(100 - i);
    			Delay_ms(10);
    		}
    		
    	}
    }
    

    　　

• 参考资料
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