ʹCMP1,PʹGPIO루PC0NʹGPIO루PC1
 ʩ״̬
 2.5V             -> PC0
   0V              -> PC1
 PA4 -> HIGH 


ڱԴѡTIM8OC4
TIM8ͨ4PC5PWMΣΪߵƽʱPA4 -> LOW. 

