51 single-chip computer serial communication example

Question: Send a 0-255 in 16 of any number, when the microcontroller received after the dynamic display on the digital tube, the baud rate is self-determined.

#include <reg52.h> #define UCHAR unsigned char #define UINT unsigned int sbit Duan =p2^6;
Sbit Wei =p2^7;
Uchar Code table[]={0x3f,0x06,0x5b,0x4f, 0x66,0x6d,0x7d,0x07, 0x7f,0x6f,0x77,0x7c, 0x39,0x5e,0x79,0x71};
UCHAR Flag;
Uchar Bai,shi,ge;
UINT Num;
void Init ();
void display (Uchar Bai,char shi,uchar ge);
 void delay (UINT XMS) {UINT I,j;
for (i=0;i<xms;i++) for (j=0;j<10;j++);
 } void Main () {init ();
    while (1) {if (flag==1) {es=0;
    flag=0;
    bai=num/100;
    SHI=NUM%100/10;
    ge=num%10;
    /*sbuf=bai; while (!
    TI);
    ti=0;
    Sbuf=shi; while (!
    TI);
    ti=0;
    Sbuf=ge; while (!
    TI); 
      ti=0;*/Es=1;
    } display (bai,shi,ge);//If the function is written in the previous loop, it will go wrong, only one digit is displayed ....
    }} void Display (Uchar Bai,uchar shi,uchar ge) {wei=1;
    P0=0xfe;
    wei=0;
    P0=0xff;
    Duan=1;
    P0=table[bai];
    duan=0;
    P0=0xff;

    Delay (2);
    Wei=1;
    P0=0XFD;
    wei=0;
    P0=0xff;
    Duan=1;
    P0=table[shi];
   duan=0; P0=0xff;

    Delay (2);
    Wei=1;
    P0=0XFB;
    wei=0;
    P0=0xff;
    Duan=1;
    P0=table[ge];
    duan=0;
    P0=0xff;

Delay (2);
  } void Init () {tmod=0x20;
  TH1=0XFD;
  TL1=0XFD;
  sm0=0;
  Sm1=1;
  Tr1=1;
  Ren=1;
  Ea=1;

Es=1;
 } void Ser () interrupt 4 {num=sbuf;
 flag=1;


ri=0; }

Question: Send any byte data from the computer in 9600bps, when the microcontroller receives the data, add a sequence number before this data and send it together with this data to the computer, when the serial number exceeds 255 zero.

#include <reg52.h>
#define UCHAR unsigned char
#define UINT unsigned int
uchar AA;
Uchar Num;
UCHAR Flag;
void Init ();
void Main ()
{
 init ();
 while (1)
 {
   if (flag==1)
   {
      flag=0;
      es=0;             
      if (num==255)
      num=0;
      Sbuf=num;
      while (! TI);
      ti=0;
      SBUF=AA;
      while (! TI);
      ti=0;
      Es=1
;
}}} void init ()
{
 tmod=0x20;
 TH1=0XFD;
 TL1=0XFD;
 sm0=0;
 sm1=1;
 tr1=1;
 ea=1;
 Es=1;
 Ren=1;
 num=0;
}

void Ser () Interrupt 4
{
 flag=1;
 ri=0;
 Aa=sbuf;
 num++;

}