一般的單片機(jī)都只有一個(gè)串口，所以必須模擬一個(gè)出來(lái)。

/*

sbit TXD1= P1^4;//define p14 as the analog transmit port

sbit RXD1= P1^2;//define p12 as the analog recieve port

*/

#include "REG52.H"

#define uint unsigned int

#define uchar unsigned char

#include

void WaitTF0(void);

void TIMEINI(void)//counter initial

{

TMOD=0x02;

TH0=0xA0;、//9600 BPS

TL0=TH0;

TR0=1;

TF0=0;

}

void WByte(uchar input)//send function

{

uchar i=8;

TR0=1;

TXD1=0;//begin bit

WaitTF0();

//send the Byte

while(i--)

{

TXD1=input&0x01;//send Byte from low bit to high bit

WaitTF0();

input=input>>1;//right shift

}

TXD1=1;//stop bit

WaitTF0();

TR0=0;//stop the counter

}

uchar RByte()//the recieve function

{

uchar Output=0;

uchar i=8;

while(RXD1);

i=i;

i=i;

i=i;

i=i;

i=i;

i=i;

i=i;

TR0=1;//計(jì)數(shù)器開(kāi)始工作

WaitTF0();

while(i--)//接收8位數(shù)據(jù)位

{

Output>>=1;

if(RXD1)Output=Output|0x80;//recieve from the high bit to low bit

WaitTF0();

}

TR0=0;

returnOutput;

}

void WaitTF0(void)//check the counter

{

while(!TF0);

TF0=0;

}