if(u==10)
       {                                                
             u=0;
             flag++;
        
            temp=read_AD(CH1)*2;//电阻分压过，值要乘2
              
            if(temp<5590)//高于0度
            {
                LED=1;
              temp=(temp-5590)/-40;
            }
            if(temp>5590)//低于0度
            {
                LED=0;
                temp=(temp-5590)/40;
            
            }    
        
                 shi=temp%100/10;  //取十位
                ge=temp%10;          //取个位
        }