aa867734398的博客

void beep_init(void){ GPIOC.ALTFN0 &= ~(3<<28); GPIOC.ALTFN0 |= (1<<28); GPIOC.OUTENB |= (1<<14); GPIOC.OUT &= ~(1<<14);}void beep_open(void){ GPIOC.OUT |= ...