老哥们，我做了一个呼吸灯，用的是PB8 对应的是TIM4 CH3，但是只是实现了闪烁的效果，亮度并没有发生改变。求指教

木偶人的感情 · 发表于 2020-4-22 10:54:35

板子是STM32F103C8T6

u16 ledOpwmval;
int main(void)
{

u8 dir=1;
delay_init();
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
uart_init(115200);
Init_LEDpin();
TIM4_Int_Init(7999,8999);
while(1)
{
      delay_ms(10);
      if(dir == 1) ledOpwmval++;
      else ledOpwmval--;

      if(ledOpwmval>3999) dir = 0;
      if(ledOpwmval==0) dir = 1;
      TIM_SetCompare3(TIM4,ledOpwmval);
}
}

void TIM4_Int_Init(u16 arr,u16 psc)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStrue;
NVIC_InitTypeDef NVIC_InitStructture;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4,ENABLE);

TIM_TimeBaseInitStrue.TIM_Period = arr;
TIM_TimeBaseInitStrue.TIM_Prescaler = psc;
TIM_TimeBaseInitStrue.TIM_CounterMode =TIM_CounterMode_Up;
TIM_TimeBaseInitStrue.TIM_ClockDivision =0;
TIM_TimeBaseInit(TIM4,&TIM_TimeBaseInitStrue);

TIM_ITConfig(TIM4,TIM_IT_Update,ENABLE);

NVIC_InitStructture.NVIC_IRQChannel = TIM4_IRQn;
NVIC_InitStructture.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructture.NVIC_IRQChannelSubPriority = 3;
NVIC_InitStructture.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructture);

TIM_Cmd(TIM4,ENABLE);
}

void TIM4_IRQHandler(void)
{
if(TIM_GetITStatus(TIM4,TIM_IT_Update)!=RESET)
{
      LED1=!LED1;
      TIM_ClearITPendingBit(TIM4,TIM_IT_Update);
}
}
void TIM4_PWM_Init(u16 arr,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStrue;
TIM_OCInitTypeDef TIM_OCInitTypeStrue;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4,ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB|RCC_APB2Periph_AFIO,ENABLE);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;    // ¶Ë¿úÅäÖÃ
   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
   GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;    //IO¿úËù¶èÎa50MHz
   GPIO_Init(GPIOB, &GPIO_InitStructure);

TIM_TimeBaseInitStrue.TIM_Period = arr;
TIM_TimeBaseInitStrue.TIM_Prescaler = psc;
TIM_TimeBaseInitStrue.TIM_CounterMode =TIM_CounterMode_Up;
TIM_TimeBaseInitStrue.TIM_ClockDivision =0;
TIM_TimeBaseInit(TIM4,&TIM_TimeBaseInitStrue);

TIM_OCInitTypeStrue.TIM_OCMode =TIM_OCMode_PWM1;
TIM_OCInitTypeStrue.TIM_OCNPolarity =TIM_OCPolarity_High;
TIM_OCInitTypeStrue.TIM_OutputState =TIM_OutputState_Enable;
TIM_OC3Init(TIM4, &TIM_OCInitTypeStrue);

TIM_OC3PreloadConfig(TIM4,TIM_OCPreload_Enable);
TIM_Cmd(TIM4,ENABLE);
}