C51单片机多机通信C语言

2024-12-22 11:25:54

推荐回答（2个）

回答1：

单片机a,b,c. a为主机，bc为从机。a上有一个外部中断0输入，按第一次a的两个LED亮500ms，再按一下，b机的两个LED灯亮500ms，第三次按下c机的两个LED灯亮500ms，然后周而复始。两个数码管分别显示0/1/2, 和abc（bc由从机反馈）

主从通信基本步骤：

1．主机从机初始化为方式2或者3，从机都置SM2=1，允许中断

2．主机置TB8=1，发送从机地址

3．所有从机均接收主机发送要寻址的从机地址

4．被寻址的从机确认地址后，置本机SM2=0，向主机返回地址，供主机核对

5．核对无误后，主机向被寻址的从机发送命令，通知从机接受或者发送数据。

6．本次通信结束后，主从机重置SM2=1，主机可再对其他从机寻址

******************************************************************

主机a：

******************************************************************

#include

#define uchar unsigned char

#define uint unsigned int

uchar leddata[]={0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F,0x77,0x7C,0x39,0x5E,0x79,0x71,0x40,0x00};

uchar Mode;

sbit P10 = P1^0;

sbit P13 = P1^3;

sbit P17 = P1^7;

sbit P20 = P2^0;

sbit P21 = P2^1;

void UART_init()

{

TMOD = 0x20;

TH1 = 0xfd;

TL1 = 0xfd;

TR1 = 1;

SCON = 0xd0;

ES = 1;

EX0 = 1;

IT0 = 1; //INT0下跳触发

EA = 1;

TI = 0;

}

void DelayMs(int ms)

{

uchar i;

while(ms--)

for(i=0; i<120; i++);

}

void putc_to_SerialPort(uchar c)

{

SBUF = c;

while(TI == 0);

TI = 0;

}

void MasterControl(unsigned char Addr, unsigned char Comd)

{

TB8 = 1;

putc_to_SerialPort(Addr);

DelayMs(50);

TB8 = 0;

putc_to_SerialPort(Comd);

DelayMs(50);

}

Ex0_int(void) interrupt 0

{

P0 = leddata[Mode];

P20 = 0;

if(Mode == 0)

{

P2 = leddata[10];

P10 = 0;

P13 = 0;

DelayMs(500);

P10 = 1;

P13 = 1;

// MasterControl('b','C');

// MasterControl('c','C');

}

else if(Mode == 1)

{

P10 = 1;

P13 = 1;

MasterControl('b','O');

// MasterControl('c','C');

}

else if(Mode == 2)

{

P10 = 1;

P13 = 1;

// MasterControl('b','C');

MasterControl('c','O');

}

Mode = (Mode + 1) % 3;

}

com_int(void) interrupt 4

{

if(RI)

{

RI = 0;

if(SBUF == 'b')

{

P2 = leddata[11];

}

if(SBUF == 'c')

{

P2 = leddata[12];

}

void main(void)

{

P0 = 0x00;

P1 = 0xff;

P2 = 0x00;

UART_init();

Mode = 0;

while(1);

}

******************************************************************

从机b：

******************************************************************

#include

#define uchar unsigned char

uchar RecData;

sbit P10 = P1^0;

sbit P13 = P1^3;

void UART_init()

{

TMOD = 0x21;

TH1 = 0xfd;

TL1 = 0xfd;

TR1 = 1;

SCON = 0xf0;

ES = 1;

PS = 1;

EA = 1;

}

void DelayMs(int ms)

{

uchar i;

while(ms--)

for(i=0; i<120; i++);

}

void putc_to_SerialPort(uchar c)

{

SBUF = c;

while(TI == 0);

TI = 0;

}

com_int(void) interrupt 4

{

if(RI)

{

RecData = SBUF;

RI = 0;

if(RB8 == 1) //地址

{

if(RecData == 'b') //是自己的地址,置SM2=0,准备接受数据

{

SM2 = 0;

putc_to_SerialPort('b');

}

else //不是自己的地址

{

SM2 = 1;

}

if(RB8 == 0) //数据

{

if(RecData=='O')

{

P10 = 0;

P13 = 0;

DelayMs(500);

P10 = 1;

P13 = 1;

}

if(RecData=='C')

{

P10 = 1;

P13 = 1;

}

SM2 = 1;

}

void main(void)

{

P0 = 0xff;

P1 = 0xff;

UART_init();

while(1);

}

******************************************************************

从机c：

******************************************************************

#include

#define uchar unsigned char

uchar RecData;

sbit P10 = P1^0;

sbit P13 = P1^3;

void UART_init()

{

TMOD = 0x21;

TH1 = 0xfd;

TL1 = 0xfd;

TR1 = 1;

SCON = 0xf0;

ES = 1;

PS = 1;

EA = 1;

}

void DelayMs(int ms)

{

uchar i;

while(ms--)

for(i=0; i<120; i++);

}

void putc_to_SerialPort(uchar c)

{

SBUF = c;

while(TI == 0);

TI = 0;

}

com_int(void) interrupt 4

{

if(RI)

{

RecData = SBUF;

RI = 0;

if(RB8 == 1) //地址

{

if(RecData == 'c') //是自己的地址,置SM2=0,准备接受数据

{

SM2 = 0;

putc_to_SerialPort('c');

}

else //不是自己的地址

{

SM2 = 1;

}

if(RB8 == 0) //数据

{

if(RecData=='O')

{

P10 = 0;

P13 = 0;

DelayMs(500);

P10 = 1;

P13 = 1;

SM2 = 1;

}

if(RecData=='C')

{

P10 = 1;

P13 = 1;

SM2 = 1;

}

void main(void)

{

P0 = 0xff;

P1 = 0xff;

UART_init();

while(1);

}

回答2：

哥们，建议你多看看基础的书吧！