//初始化串口
void init_serialcomm(void)
{
    SCON  = 0x50;       //SCON: serial mode 1, 8-bit UART, enable ucvr
    TMOD |= 0x20;       //TMOD: timer 1, mode 2, 8-bit reload
    PCON |= 0x80;       //SMOD=1;
    TH1   = 0xF4;       //Baud:4800  fosc=11.0592MHz
    IE   |= 0x90;       //Enable Serial Interrupt
    TR1   = 1;          // timer 1 run
   // TI=1;
}


void send_char_com(unsigned char ch)  
{
    SBUF=ch;
    while(TI==0);
    TI=0;
}

//向串口發送一個字符串,strlen為該字符串長度
void send_string_com(unsigned char *str,unsigned int strlen)
{
    unsigned int k=0;
    do
    {
        send_char_com(*(str + k));
        k++;
    } while(k < strlen);
}


//串口接收中斷函數
void serial () interrupt 4 using 3
{


unsigned char checksum,count3;
if(RI)
    {
        unsigned char ch;
        RI = 0;
        ch=SBUF;
       if(ch==255)
        {
             count3=0;
             Serial_Inbuf1[count3]=ch;
             checksum= ch-128;
        }
        else
        {
             count3++;
             Serial_Inbuf1[count3]=ch;
             checksum ^= ch;
          
             
             if( (count3==(INBUF_LEN-1)) && (!checksum) )
             {
                 //read_flag=1; 
                 event_word |= EVENT_RS232_ARRIVED;//如果串口接收的數據達到INBUF_LEN個,且校驗沒錯,
                               //就置位取數標志
             }
        }

            
    }
}