用stc89c52rc单片机为辅机和stc15w408as单片机为主机进行串口通信的代码，让stc89c52rc单片机通过矩阵按键1或者2发送指令，stc15w408as单片机进行接收，相对应按键后让P5^4为引脚的LED亮，让stc89c52rc单片机在ld1602显示的温度数加1，相反减1

以下是用stc89c52rc单片机为辅机和stc15w408as单片机为主机进行串口通信的代码：

stc89c52rc单片机代码：

#include <reg52.h>
#include <intrins.h>

#define FOSC 11059200L
#define BAUD 9600
#define TIMER_1MS (65536-FOSC/12/1000)

sbit Matrix1 = P2^0;
sbit Matrix2 = P2^1;

unsigned char TxdData;
unsigned char ReceiveData;
unsigned char TxdFlag = 0;

void SendData(unsigned char dat);
void DelayMs(unsigned int ms);
void InitUart();
void MatrixScan();

void main()
{
    InitUart();
    while(1)
    {
        MatrixScan();
        if(Matrix1 == 0)
        {
            SendData('1');
            while(Matrix1 == 0);
            P5^4 = 1;
            DelayMs(10);
            P5^4 = 0;
        }
        if(Matrix2 == 0)
        {
            SendData('2');
            while(Matrix2 == 0);
            P5^4 = 1;
            DelayMs(10);
            P5^4 = 0;
        }
    }
}

void SendData(unsigned char dat)
{
    SBUF = dat;
    while(!TxdFlag);
    TxdFlag = 0;
}

void DelayMs(unsigned int ms)
{
    unsigned int i,j;
    for(i=ms; i>0; i--)
        for(j=110; j>0; j--);
}

void InitUart()
{
    TMOD &= 0x0F;
    TMOD |= 0x20;
    TH1 = TIMER_1MS / BAUD;
    TL1 = TIMER_1MS % BAUD;
    TR1 = 1;
    ES = 1;
    EA = 1;
}

void MatrixScan()
{
    unsigned char i;
    static unsigned char code KeyTable[] =
    {
        0x7f,0xbf,0xdf,0xef,
        0xf7,0xfb,0xfd,0xfe
    };
    for(i=0; i<8; i++)
    {
        P1 = KeyTable[i];
        _nop_();
        if((P1 & 0x0f) != 0x0f)
            break;
    }
    if(i < 8)
    {
        switch(i)
        {
            case 0: ReceiveData = '1'; break;
            case 1: ReceiveData = '4'; break;
            case 2: ReceiveData = '7'; break;
            case 3: ReceiveData = '*'; break;
            case 4: ReceiveData = '2'; break;
            case 5: ReceiveData = '5'; break;
            case 6: ReceiveData = '8'; break;
            case 7: ReceiveData = '0'; break;
            default: break;
        }
    }
    else ReceiveData = 0;
}

void UartIsr() interrupt 4
{
    if(RI)
    {
        RI = 0;
        ReceiveData = SBUF;
        if(ReceiveData == '1')
        {
            P5^4 = 1;
            DelayMs(10);
            P5^4 = 0;
        }
        if(ReceiveData == '2')
        {
            P5^4 = 1;
            DelayMs(10);
            P5^4 = 0;
        }
    }
    if(TI)
    {
        TI = 0;
        TxdFlag = 1;
    }
}

stc15w408as单片机代码：

#include <REG52.H>
#include <stdio.h>

#define FOSC 22118400L
#define BAUD 9600
#define TIMER_1MS (65536-FOSC/12/1000)

sbit LED = P5^4;

unsigned char TxdData;
unsigned char ReceiveData;
unsigned char Temperature = 25;
unsigned char TxdFlag = 0;

void SendData(unsigned char dat);
void InitUart();
void InitTimer0();
void Timer0Isr() interrupt 1;
void UartIsr() interrupt 4;

void main()
{
    InitUart();
    InitTimer0();
    while(1);
}

void SendData(unsigned char dat)
{
    SBUF = dat;
    while(!TxdFlag);
    TxdFlag = 0;
}

void InitUart()
{
    TMOD &= 0x0F;
    TMOD |= 0x20;
    TH1 = TIMER_1MS / BAUD;
    TL1 = TIMER_1MS % BAUD;
    TR1 = 1;
    ES = 1;
    EA = 1;
}

void InitTimer0()
{
    TMOD &= 0xF0;
    TMOD |= 0x01;
    TH0 = TIMER_1MS / 1000;
    TL0 = TIMER_1MS % 1000;
    ET0 = 1;
    EA = 1;
    TR0 = 1;
}

void Timer0Isr() interrupt 1
{
    TH0 = TIMER_1MS / 1000;
    TL0 = TIMER_1MS % 1000;
    Temperature++;
    if(Temperature > 40)
        Temperature = 25;
}

void UartIsr() interrupt 4
{
    if(RI)
    {
        RI = 0;
        ReceiveData = SBUF;
        if(ReceiveData == '1')
            LED = 1;
        if(ReceiveData == '2')
            LED = 0;
    }
    if(TI)
    {
        TI = 0;
        TxdFlag = 1;
    }
}