51单片机串口通信c语言编程

#include <REG52.H>

#define uchar unsigned char

#define uint unsigned int

sbit ring=P3^7

sbit CASE1=P2^0

sbit CASE2=P2^1

sbit CASE3=P2^2

sbit CASE4=P2^3

uchar se=0,re=0

uchar temp=0

void wait(uint cnt)

{

while(--cnt)

}

//串口发送程序

void send(uchar se)

{

SBUF=se //发送数据

while(TI == 0)

TI = 0

}

//串口接收程序

uchar receive(void)

{

re=SBUF //接收数据

while(RI==0)

RI=0

return re

}

//串口初始化

void sinti(void)

{

SCON = 0x50

TMOD |= 0x20

TH1 = 0xFD

TR1 = 1

EA= 1

ES= 1

}

void delay(int cnt)

{

while(--cnt)

}

//主程序

int main (void)

{

int i

sinti() //串口初始化程序

ring=1

while(1)

{

while (1)

{

if(CASE1==0)

{

send('a')

ring=0

break

}

if(CASE2==0)

{

send('b')

ring=0

break

}

if(CASE3==0)

{

send('c')

ring=0

break

}

if(CASE4==0)

{

send('d')

ring=0

break

}

}

if(ring==0)

{

wait(60000)

ring=1

}

for(i=0i<10000i++)

}

}

//串口中断程序

void UART_SER (void) interrupt 4 //串行中断服务程序

{

if(RI)//判断是接收中断产生

{

RI=0 //标志位清零

temp=SBUF

}

if(TI)//如果是发送标志位，清零

TI=0

}

#include <AT89X51.H>//单片机51头文件,存放着单片机的寄存器

unsigned char dat //用于存储单片机接收发送缓冲寄存器SBUF里面的内容

sbit gewei=P2^2 //个位选通定义

sbit shiwei=P2^3//十位选通定义

unsigned char code table[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x67,0x77,0x7c,0x39,0x5e,0x79,0x71}

//{0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x67,}// 0, 1, 2, 3, 4, 5, 6, 7, 8, 9

void Delay(unsigned int tc) //延时程序

{

while( tc != 0 )

{unsigned int i

for(i=0i<100i++)

tc--}

}

void LED()//LED显示接收到的数据

{

shiwei=0

P0=~table[dat/16]

Delay(8)

shiwei=1

gewei=0

P0=~table[dat%16]

Delay(5)

gewei=1

}

void Init_Com(void)//功能:串口初始化,波特率9600，方式1

{

TMOD = 0x20

PCON = 0x00

SCON = 0x50

TH1 = 0xFd

TL1 = 0xFd

TR1 = 1

}

void main()//主程序功能:实现接收数据并把接收到的数据原样发送回去///////

{

Init_Com()//串口初始化

// P1=0xf0

while(1)

{

if ( RI ) //扫描判断是否接收到数据，

{

dat = SBUF //接收数据SBUF赋与dat

RI=0 //RI清零。

SBUF = dat //在原样把数据发送回去

}

LED() //显示接收到的数据

}

}

第一题，已经测试成功:

#include <reg52.h>

#define uchar unsigned char

#define uint unsigned int

uchar flag, a

sbit d = P0^0

void init()

{

TMOD = 0x20 //设置定时器1为工作方式2

TH1 = 0xfd

TL1 = 0xfd

TR1 = 1 //开定时器1

REN = 1 //开串口通信.

SM0 = 0 //设置串口通信方式1

SM1 = 1

EA = 1 //开总中断.

ES = 1 //开串口中断.

}

void delay(uint z)

{

uint x, y

for(x = zx >0x--) for(y = 110y >0y--)

}

void main()

{

init()

a = '4'

while(1) {

if(a == '1') {

d = 0 delay(400)

d = 1 delay(400)

}

else if(a == '2') {

d = 0 delay(200)

d = 1 delay(200)

}

else if(a == '3') {

d = 0 delay(100)

d = 1 delay(100)

}

else if(a == '4') {

d = 1

}

}

}

void ser() interrupt 4

{

if (TI == 1) {

TI = 0

}

else if (RI == 1) {

RI = 0

a = SBUF //中间变量.

flag = 1

}

}

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