單片機接收PC機發(fā)來的指令信號，然后單片機又向PC機發(fā)送字符串。具體要求如下：

當接收指令信號為：'go'，單片機向PC機發(fā)送字符串：WELCOME TO CHINA!;

當接收指令信號為：'who'，單片機向PC機發(fā)送字符串：MY NAME IS LIMING;

當接收指令信號為：'home'，單片機向PC機發(fā)送字符串：YINGYONGKEXUEXUEYUAN。

PC機上的串口調試軟件，會在窗口顯示出單片機送回來相應字符串;

如果接送的字符串不正確，單片機不響應。

采用C語言。

題目鏈接：http://zhidao.baidu.com/question/282477940.html

//---------------------------------------------------------

做而論道回答如下：

看看下面的。

//---------------------------------------------------------

#include

#include

#define uchar unsigned char

#define uint unsigned int

//---------------------------------------------------

uchar idata trdata1[] = {

'W','E','L','C','O','M','E',' ','T','O',' ','C','H','I','N','A','!',0x0d,0x0a,0x00};

uchar idata trdata2[] = {

'M','Y',' ','N','A','M','E',' ','I','S',' ','L','I','M','I','N','G',0x0d,0x0a,0x00};

uchar idata trdata3[] = {

'Y','I','N','G','Y','O','N','G','K','E','X','U','E','X','U','E','Y','U','A','N',0x0d,0x0a,0x00};

uchar RxBuf[5], Rx_p, Rx_i, TX_p, Tx_i;

//---------------------------------------------------

void UART_Init(void) //串口初始化

{

PCON = 0x00;

SCON = 0x50; //串口工作方式為1，允許接收.

TMOD = 0x20; // T1 定時方式2

TH1 = 0xfd; //波特率 9600bps @ fosc = 11.0592MHz

TL1 = 0xfd;

TR1 = 1; //啟動T1

ES = 1; //開串口中斷.

EA = 1; //開總中斷.

}

//---------------------------------------------------

void main()

{

UART_Init();

Rx_p = 0;

Rx_p = 2;

while(1) {

if (Rx_p != 0) {

TX_p = Rx_p;//字符串1 2 3

Tx_i = 0; //字符指針.

Rx_p = 0; //清零.

Rx_i = 0;

TI = 1; //啟動發(fā)送中斷.

} }

}

//---------------------------------------------------

void Uart_INT(void) interrupt 4 //串口中斷函數(shù)

{

uchar Tcv = 0;

if(RI) { //接收?.

RI = 0; //標志位清零.

RxBuf[Rx_i] = SBUF;

if((RxBuf[Rx_i - 1] == 'g') && (RxBuf[Rx_i] == 'o')) Rx_p = 1;

if((RxBuf[Rx_i - 2] == 'w') && (RxBuf[Rx_i - 1] == 'h') && (RxBuf[Rx_i] == 'o')) Rx_p = 2;

if((RxBuf[Rx_i - 3] == 'h') && (RxBuf[Rx_i - 2] == 'o') && (RxBuf[Rx_i - 1] == 'm') && (RxBuf[Rx_i] == 'e')) Rx_p = 3;

P1 = Rx_p; //在P1顯示收到的信息.

Rx_i++;

Rx_i %= 5;

}

else {

TI = 0;

if (TX_p == 1) Tcv = trdata1[Tx_i]; //取來待發(fā)字符.

if (TX_p == 2) Tcv = trdata2[Tx_i];

if (TX_p == 3) Tcv = trdata3[Tx_i];

if (Tcv != 0) {SBUF = Tcv; Tx_i++;} //不是0就發(fā)送.

}

}