问答

用ST的标准库配置PA8,PA9,PA10输出TIM1的PWM，一直没输出，代码如下： RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE); GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9| GPIO_Pin_10; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOA, &GPIO_InitStructure); GPIO_PinAFConfig(GPIOA, GPIO_PinSource8, GPIO_AF_2); // TIM1_CH1 GPIO_PinAFConfig(GPIOA, GPIO_PinSource9, GPIO_AF_2); // TIM1_CH2 GPIO_PinAFConfig(GPIOA, GPIO_PinSource10, GPIO_AF_2); // TIM1_CH3 RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE); //使能定时器1 TIM_TimeBaseStructure.TIM_Period = 1000 - 1; // ARR TIM_TimeBaseStructure.TIM_Prescaler = 48 -1; // PSC TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; TIM_TimeBaseStructure.TIM_RepetitionCounter = 0; TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure); TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; // 通道输出使能 TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable; // 互补通道关闭 TIM_OCInitStructure.TIM_Pulse = 500; // 初始占空比CCR1=0 TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; // 有效电平高 TIM_OC1Init(TIM1, &TIM_OCInitStructure); TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable); // 使能CCR预装载 TIM_OC2Init(TIM1, &TIM_OCInitStructure); TIM_OC2PreloadConfig(TIM1, TIM_OCPreload_Enable); // 使能CCR预装载 TIM_OC3Init(TIM1, &TIM_OCInitStructure); TIM_OC3PreloadConfig(TIM1, TIM_OCPreload_Enable); // 使能CCR预装载 TIM_BDTRInitStructure.TIM_OSSRState = TIM_OSSRState_Disable; TIM_BDTRInitStructure.TIM_OSSIState = TIM_OSSIState_Disable; TIM_BDTRInitStructure.TIM_LOCKLevel = TIM_LOCKLevel_OFF; TIM_BDTRInitStructure.TIM_DeadTime = 0; TIM_BDTRInitStructure.TIM_Break = TIM_Break_Disable; TIM_BDTRInitStructure.TIM_BreakPolarity = TIM_BreakPolarity_Low; TIM_BDTRInitStructure.TIM_AutomaticOutput = TIM_AutomaticOutput_Disable; TIM_BDTRConfig(TIM1, &TIM_BDTRInitStructure); TIM_CtrlPWMOutputs(TIM1, ENABLE); TIM_ARRPreloadConfig(TIM1, ENABLE); TIM_Cmd(TIM1, ENABLE); 这样配置是不是哪里有问题？