想用TIM1输出简单的pwm，输出没结果，求看看配置有什么问题

wywei · 发表于 2019-8-6 14:49:19

主函数里调用的是TIM1_PWM_Init(11250,6400);

然后函数定义是
void TIM1_PWM_Init(u16 arr,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
TIM_OCInitTypeDef  TIM_OCInitStructure;

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1 | RCC_APB2Periph_GPIOA, ENABLE);  //使能GPIO外设时钟

//设置该引脚为复用输出功能,输出TIM1 CH1的PWM脉冲波形 GPIOA.8
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8; //TIM1_CH1
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  //复用推挽输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);//初始化GPIO
//初始化TIM1
TIM_TimeBaseStructure.TIM_Period = arr; //设置在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_Down;  //TIM向下计数模式
TIM_TimeBaseStructure.TIM_RepetitionCounter=0;
TIM_TimeBaseInit(TIM1, &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TIM1CCR1的输出比较参数
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //选择定时器模式:TIM脉冲宽度调制模式1
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;//互补输出不使能
TIM_OCInitStructure.TIM_Pulse = 5625;//设置CCR的值 CCR1设置成两秒
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //输出极性:TIM输出比较极性高，CCER中CC1P位设置为1
TIM_OC1Init(TIM1, &TIM_OCInitStructure);  //根据指定的参数初始化外设TIM1 OC1

TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);  //使能TIM1在CCR1上的预装载寄存器

TIM_Cmd(TIM1, ENABLE);  //使能TIM1
}