关于PWM的翻转输出，无法输出波形

只看该作者 · 2020-6-2 16:38

求大佬们看看这是哪里的问题。
TIM.C
static void TIM3_GPIO_Config(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3 , ENABLE);
/
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB, ENABLE);

  GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_6 ;       //定时器TIM3通道1输出
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_0 ;    //led灯
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOB, &GPIO_InitStructure);
}
定时器配置
static void TIM3_Mode_Config(void)
{
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
TIM_OCInitTypeDef  TIM_OCInitStructure;

  TIM_TimeBaseStructure.TIM_Period = 999;
  TIM_TimeBaseStructure.TIM_Prescaler = 71;
  TIM_TimeBaseStructure.TIM_ClockDivision = 0 ;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = 500;
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
  TIM_OC1Init(TIM3, &TIM_OCInitStructure);
  TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);

  TIM_ARRPreloadConfig(TIM3, ENABLE);

  /* TIM3 enable counter */
  TIM_ClearFlag(TIM3,TIM_IT_CC1);
TIM_ITConfig(TIM3,TIM_IT_CC1,ENABLE);
TIM_Cmd(TIM3, ENABLE);
}

中断配置
void TIM3_NVIC_Configuration(void)
{
NVIC_InitTypeDef NVIC_InitStructure;

NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}

void TIM3_PWM_Init(void)
{
TIM3_GPIO_Config();
TIM3_Mode_Config();
}
中断函数
void TIM3_IRQHandler(void)
{
u16 temp=0;
u16 count=0;
if(TIM_GetITStatus(TIM3,TIM_IT_CC1) != RESET)
{
TIM_ClearITPendingBit(TIM3,TIM_IT_CC1);
count = TIM_GetCapture2(TIM3);
temp = count + 500;
TIM_SetCompare2(TIM3, temp);
time++;
}
}
main.c
volatile u32 time = 0;

int main(void)
{

TIM3_PWM_Init();

TIM3_NVIC_Configuration();

while (1)
{
if(time == 2000)
{
time = 0;
GPIOB ->ODR ^=GPIO_Pin_0;
}
}
}