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);
} |