stm32f303RE PWM输出波形变形

today123-335437 提问时间：2023-12-18 10:51 / 已解决

问答
是否解决:	已解决

我使用stm32 nucleo开发板，使用TIM3 CH4输出PWM方波，发现波形变形，整个工程只有这个PWM输出的功能，其他外设都没开启。工程使用的是标准库。请大神支个招。

void TIM_Config(void)

{

    GPIO_InitTypeDef  GPIO_InitStructure;
    TIM_TimeBaseInitTypeDef  TIM_TimeBaseInitStructure;
    TIM_OCInitTypeDef  TIM_OCInitStructure;
    TIM_BDTRInitTypeDef TIM_BDTRInitStructure;

    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB,ENABLE);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//GPIO_Mode_AF
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_Init(GPIOB,&GPIO_InitStructure);

    GPIO_PinAFConfig(GPIOB,GPIO_PinSource7,GPIO_AF_10);

    RCC_APB1PeriphClockCmd(RCC_APB1ENR_TIM3EN,ENABLE);

        TIM_TimeBaseInitStructure.TIM_Prescaler = 71;
    TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInitStructure.TIM_Period = 499;
    TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1 ;
    TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0x00;
    TIM_TimeBaseInit(TIM3,&TIM_TimeBaseInitStructure);

    TIM_OCStructInit(&TIM_OCInitStructure);
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;
    TIM_OCInitStructure.TIM_Pulse =250;
    TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset;
        TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Set;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;
    TIM_OC4Init(TIM3,&TIM_OCInitStructure);

    TIM_Cmd(TIM3,ENABLE);
    TIM_CtrlPWMOutputs(TIM3,ENABLE);

}