STM32F030 PWM更新问题

debug

void PWM_GPIO_Config(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;


  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA | RCC_AHBPeriph_GPIOB, ENABLE);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ;
  GPIO_Init(GPIOA, &GPIO_InitStructure);       
  GPIO_PinAFConfig(GPIOA, GPIO_PinSource9, GPIO_AF_2);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ;
  GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource0, GPIO_AF_2);


        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;  
        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_Level_2;  
        GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;  
        GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;  
        GPIO_Init(GPIOB , &GPIO_InitStructure);   
        GPIO_PinAFConfig(GPIOB, GPIO_PinSource12, GPIO_AF_2);
}

void TIM_PWM_Config(void)
{
       
        NVIC_InitTypeDef NVIC_InitStructure;
        TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
        TIM_OCInitTypeDef  TIM_OCInitStructure;
        TIM_BDTRInitTypeDef TIM_BDTRInitStructure;
       
        RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1 , ENABLE);


  TimerPeriod = (SystemCoreClock / 100000) - 1;//100kHz

  TIM_TimeBaseStructure.TIM_Prescaler = 0;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  
  TIM_TimeBaseStructure.TIM_Period = TimerPeriod;
  TIM_TimeBaseStructure.TIM_ClockDivision = 0;
  TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;

  TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);


  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCNPolarity_High;
  TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;
  TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset;
  TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Set;



  TIM_OCInitStructure.TIM_Pulse = Channel2Pulse;
  TIM_OC2Init(TIM1, &TIM_OCInitStructure);

        TIM_BDTRInitStructure.TIM_OSSRState = TIM_OSSRState_Enable;  
  TIM_BDTRInitStructure.TIM_OSSIState = TIM_OSSIState_Enable;  
  TIM_BDTRInitStructure.TIM_LOCKLevel = TIM_LOCKLevel_OFF;  
  TIM_BDTRInitStructure.TIM_DeadTime = 2; //0~127
  TIM_BDTRInitStructure.TIM_Break = TIM_Break_Enable;  
  TIM_BDTRInitStructure.TIM_BreakPolarity = TIM_BreakPolarity_Low;  
  TIM_BDTRInitStructure.TIM_AutomaticOutput = TIM_AutomaticOutput_Enable;  
  TIM_BDTRConfig(TIM1, &TIM_BDTRInitStructure);  

  TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);  
  TIM_ARRPreloadConfig(TIM1, ENABLE);

        NVIC_InitStructure.NVIC_IRQChannel = TIM1_CC_IRQn;
        NVIC_InitStructure.NVIC_IRQChannelPriority = 1;
        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
        NVIC_Init(&NVIC_InitStructure);

  TIM_Cmd(TIM1, ENABLE);       

}
void TIM1_PWM_Update(uint16_t duty)        
{

        TIM_OCInitTypeDef  TIM_OCInitStructure;
       
  Channel2Pulse = (uint16_t) (((uint32_t)duty * (TimerPeriod - 1)) / 1000);

       
  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;

  TIM_OCInitStructure.TIM_Pulse = Channel2Pulse;
  TIM_OC2Init(TIM1, &TIM_OCInitStructure);

  TIM_CtrlPWMOutputs(TIM1, ENABLE);       
}

每隔一定时间调用TIM1_PWM_Update；
                        u16DutyCalculation = 333;

                        TIM1_PWM_Update(u16DutyCalculation);
周期性（与调用周期时间一致）的出现图中占空比乱的现象。

debug

        u16Pulse = (uint16_t) (((uint32_t) duty * (TimerPeriod - 1)) / 1000);
        TIM_SetCompare2(TIM1,u16Pulse);
        TIM_CtrlPWMOutputs(TIM1, ENABLE);

正点原子

开启APRE试试