TIM_IS.TIM_Prescaler =720;//PWM周期20ms 50HzTIM_IS.TIM_ClockDivision = TIM_CKD_DIV1; TIM_IS.TIM_CounterMode = TIM_CounterMode_Up; TIM_TimeBaseInit(TIM2,&TIM_IS); TIM_OC_IS.TIM_OCMode = TIM_OCMode_PWM1; TIM_OC_IS.TIM_OutputState = TIM_OutputState_Enable; TIM_OC_IS.TIM_OCPol...