Tim3的通道1打开后，我自己打开通道2，然后通道1调占空比没用了

22599967 · 发表于 2016-5-18 15:32:55

哪里有问题，通道1一直是低电平，led灯一直亮，不能变亮变暗了，通道2正常，哪里写的有问题？

void TIM3_PWM_Init(u32 arr,u32 psc)
{
//此部分需手动修改IO口设置

GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
TIM_OCInitTypeDef  TIM_OCInitStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE);    //TIM3时钟使能
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE); //使能PORTF时钟

GPIO_PinAFConfig(GPIOA,GPIO_PinSource6|GPIO_PinSource7,GPIO_AF_TIM3); //GPIOA6\A7复用为定时器3

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6|GPIO_Pin_7;          //GPIOA6\A7
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;       //复用功能
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz; //速度100MHz
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;    //推挽复用输出
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;       //上拉
GPIO_Init(GPIOA,&GPIO_InitStructure);             //初始化PA6

TIM_TimeBaseStructure.TIM_Prescaler=psc;  //定时器分频
TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式
TIM_TimeBaseStructure.TIM_Period=arr; //自动重装载值
TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1;

TIM_TimeBaseInit(TIM3,&TIM_TimeBaseStructure);//初始化定时器3

//初始化TIM3 Channel1 PWM模式
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //选择定时器模式:TIM脉冲宽度调制模式2
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; //输出极性:TIM输出比较极性低
TIM_OC1Init(TIM3, &TIM_OCInitStructure);  //根据T指定的参数初始化外设TIM1 4OC1

TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);  //使能TIM3在CCR1上的预装载寄存器

//初始化TIM3 Channel2 PWM模式
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //选择定时器模式:TIM脉冲宽度调制模式2
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; //输出极性:TIM输出比较极性低
TIM_OC2Init(TIM3, &TIM_OCInitStructure);  //根据T指定的参数初始化外设TIM1 4OC1

TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);  //使能TIM3在CCR1上的预装载寄存器

TIM_ARRPreloadConfig(TIM3,ENABLE);//ARPE使能

TIM_Cmd(TIM3, ENABLE);  //使能TIM3


}