STM32做的程序有人帮我看一下怎么处理吗 -

#include "system.h"
#include "SysTick.h"
#include "led.h"
#include "usart.h"
#include "beep.h"
#include "key.h"

int main(void)
{
u8 key,i;
u8 set=0;
u8 t=0;
u8 m=0;
u8 h=0;
u8 num=t+m*60+h*360;
LED_Init();
BEEP_Init();
KEY_Init();
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
USART1_Init(9600);


while(1)
{
            key=KEY_Scan(0);
            switch(key)
            {
                     case KEY_UP: set=set+1;break;
                     case KEY_DOWN: set=set-1;break;
            }
            i++;
            if(i%20==0)
            {
                     led1=!led1;
            }
            delay_ms(10);
                     if(set<num)
                     {
                              beep=!beep;
                     }
                              else
                              {
      printf(" \r\n %dê±%d·Ö%dÃë \r\n",h,m,t);
                                    delay_ms(1000);
                                 t++;
                                    if(t%60==0)
                                    {
                                             m=t/60+m;
                                             if(m%60==0)
                                             {
                                                      h=m/60+h;
                                    printf(" \r\n %dê±%d·Ö%dÃë \r\n",m,t,h);
                                                      m=0;
                                             }
                                    else       printf(" \r\n %dê±%d·Ö%dÃë \r\n",h,t,m);
                                                t=0;
                                    }
                              }
                     }
            }