stm32pwm呼吸灯定时器2通道3无效

只看该作者 · 2022-10-17 23:41

初始化stm32的定时器2的PA1,2,3做pwm呼吸灯，但是通道2通道4都可以控制亮灭，通道3（PA2）一直常亮，不明白为什么

void TIM_Config(void)
{
static GPIO_InitTypeDef GPIO_InitStructure;
static TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
static TIM_OCInitTypeDef TIM_OCInitStructure;

只看该作者 · 2022-10-17 23:42

复制

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);  

 

GPIO_InitStructure.GPIO_Pin=GPIO_Pin_1|GPIO_Pin_2|GPIO_Pin_3;//选择GPIOA组的第123根引脚

GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP;//选择引脚为复用推挽功能

GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;//选择引脚速度    

GPIO_Init(GPIOA,&GPIO_InitStructure); //初始化GPIOA

 

TIM_TimeBaseStructure.TIM_Period=999;        //计数值

TIM_TimeBaseStructure.TIM_Prescaler=71;            //分频值

TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数

TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1;

TIM_TimeBaseInit(TIM2,&TIM_TimeBaseStructure);  //初始化定时器

    

 

TIM_OCInitStructure.TIM_OCMode=TIM_OCMode_PWM2;

TIM_OCInitStructure.TIM_OutputState=TIM_OutputState_Enable;//打开或者关闭脉冲输出

TIM_OCInitStructure.TIM_Pulse = 0;    //比较值

TIM_OCInitStructure.TIM_OCPolarity=TIM_OCPolarity_High; //有效电平设置为高状态        

TIM_OC2Init(TIM2,&TIM_OCInitStructure);//初始化定时器通道2

TIM_OC3Init(TIM2,&TIM_OCInitStructure);//3

TIM_OC4Init(TIM2,&TIM_OCInitStructure);//4

 

 

TIM_Cmd(TIM2,ENABLE);

TIM_OC2PreloadConfig(TIM2,TIM_OCPreload_Enable);

TIM_OC3PreloadConfig(TIM2,TIM_OCPreload_Enable);

TIM_OC4PreloadConfig(TIM2,TIM_OCPreload_Enable);

TIM_ARRPreloadConfig(TIM2,ENABLE);