配置注意:
void TIM1_Int_Init(u16 arr,u16 psc)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE); //①时钟 TIM1 使能
//定时器 TIM1 初始化
TIM_TimeBaseStructure.TIM_Period = arr