Stm32_标准库_4_TIM中断_PWM波形_呼吸灯

基本原理

PWM相关物理量的求法

呼吸灯代码

#include "stm32f10x.h"    // Device header
#include "Delay.h"

TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
TIM_OCInitTypeDef TIM_OCInitStructuer;//结构体
GPIO_InitTypeDef GPIO_InitStructur;//定义变量结构体
 


void GPIOA_Init(void){
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
	GPIO_InitStructur.GPIO_Mode = GPIO_Mode_AF_PP;
	GPIO_InitStructur.GPIO_Pin = GPIO_Pin_0;		//GPIO_Pin_15;
	GPIO_InitStructur.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructur);
}

void PWM_Init(void){ //pwm波形配置
	   TIM_OCStructInit(&TIM_OCInitStructuer);//给不需要配置的结构体成员赋予初始值
	   TIM_OCInitStructuer.TIM_OCMode = TIM_OCMode_PWM1; //输出比较模式
	   TIM_OCInitStructuer.TIM_OCPolarity = TIM_OCPolarity_High; //极性
	   TIM_OCInitStructuer.TIM_OutputState = TIM_OutputState_Enable; //输出使能
	   TIM_OCInitStructuer.TIM_Pulse = 0; //CCR,频率1kHZ,占空比50%的PWM波形
	   TIM_OC1Init(TIM2, &TIM_OCInitStructuer);//配置GPIOA端口通道
}

/*定时器定时中断代码*/

void Timer_Init(void)//使用TM2定时器
{
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
	
	GPIOA_Init();
	
	TIM_InternalClockConfig(TIM2);
	
	 
	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(TIM2, &TIM_TimeBaseInitStructure);
	
	
	PWM_Init();
	 
	
	TIM_Cmd(TIM2, ENABLE);//启动定时器
}

/*CCR控制灯的亮度在运行过程中不断更改CCR的值来达到呼吸效果*/ //CCR[0~100]值越大灯越亮
void PWM_setcompare1(uint16_t compare){
	   TIM_SetCompare1(TIM2, compare);
}

uint8_t i;
	
int main(void){
	Timer_Init();
 
	while(1){
		 for(i = 0; i <= 100; i ++){
			   PWM_setcompare1(i);
			   Delay_ms(10);
		 }
		 for(i = 0; i <= 100; i ++){
			   PWM_setcompare1(100 - i);
			   Delay_ms(10);
		 }
	}
}
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注：TIM_OutputState 和 TIM_OutputNState不同

效果：

亮度会由暗变亮再变暗循环往复