STM32 TIM4 CH3 无法正常输出PWM

ID:196216 · 发表于 2020-5-15 14:44

TIM4配置程序如下

void TIM4_PWM_Init(u16 arr,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
TIM_OCInitTypeDef  TIM_OCInitStructure;
NVIC_InitTypeDef NVIC_InitStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE); //使能定时器3时钟

   RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB|RCC_APB2Periph_AFIO, ENABLE);  //使能GPIO外设和AFIO复用功能模块时钟

// GPIO_PinRemapConfig(GPIO_Remap_TIM4, ENABLE); //Timer4完全重映射
      /* 不重映射，RCT6没有GPIOD以上引脚由单片机引脚而设定    */

//设置该引脚为复用输出功能,输出TIM4 CH3的PWM脉冲波形 GPIOB.8
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8; //TIM_CH3
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  //复用推挽输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);//初始化GPIO

/*****TIME4定时器中断*******/

   TIM_ITConfig(TIM4,TIM_IT_Update,ENABLE ); //使能指定的TIM4中断,允许更新中断

NVIC_InitStructure.NVIC_IRQChannel = TIM4_IRQn;  //TIM3中断
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;  //先占优先级0级
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;  //从优先级3级
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能
NVIC_Init(&NVIC_InitStructure);  //初始化NVIC寄存器

//初始化TIM4
TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值
TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //TIM向上计数模式
TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位

//初始化TIM4 Channel2M?PWＪ?
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //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low
TIM_OC3Init(TIM4, &TIM_OCInitStructure);  //根据T指定的参数初始化外设TIM4 OC2

TIM_OC3PreloadConfig(TIM4, TIM_OCPreload_Enable);  //使能TIM4在CCR2上的预装载寄存器

TIM_Cmd(TIM4, ENABLE);  //使能TIM3
}

/*定时器4中断服务程序*/

void TIM4_IRQHandler(void) //TIM3中断
{
static int i=0;

if (TIM_GetITStatus(TIM4, TIM_IT_Update) != RESET) //检查指定的TIM中断发生与否:TIM 中断源
      {
      TIM_ClearITPendingBit(TIM4, TIM_IT_Update  );  //清除TIMx的中断待处理位:TIM 中断源
      i++;
//             if(i==1200)
//             {
//             i=0;
//                   TIM_Cmd(TIM4, DISABLE);
//             }

      }
}

主程序如下：
int main(void)
{
  // Init_12864();
   Motor_Init();
// LCD_P6x8Str(2,0,"BMP180:");
TIM4_PWM_Init(100,0);
while(1)
{
      TIM_SetCompare3(TIM4,50);
}
}

帐号		自动登录	找回密码
密码			立即注册