Display a string at once using serial comm.

 

 Code : 

#include<reg51.h>                              // Include 8051 library.void ser_init();                                    // Initialize serial communications.

unsigned char p[100];                       // Store the string received from user.

void rx_word(unsigned int len);        // receive string from user.

void rx_word(unsigned char a[]);     //  transmit string of user.

void tx(unsigned char w);                 // transmit character of string.

unsigned char rx();                           // receive character of string.

void main()                                                 // Main function starts

{

ser_init();                                            // Serial function calling

rx_word(8);                                       // receive string from user of length 8

tx_word(p);                                        // transmit function for displaying data.

}

void ser_init()                                           // Serial transmission function

{

SCON = 0X50;                                // Mode 1 (8-bit UART ) 

TMOD = 0X20;                               // Timer 1 in Mode 2.

TH1 = 0XFD;                                  // Baud rate of 9600.

TR1 = 1;                                          // Timer run flag enabled.

}

void tx(unsigned char w)                      // Transmit function.

{

SBUF = w;                               // SBUF temporary buffer location where character is stored.

while(TI==0);                           // Wait until transmission completed flag gets high. TI=0;                                       // Once high , make it zero for the next character.

} 

void tx_word(unsigned char a[])       // transmit function for character stored in array

{

int i;                                           // integer i

for(i=0;a[i]!='\0';i++)             //  for loop until null is reached

{

tx(a[i]);                            // transmit function

  }

}

unsigned char rx()                                     // Receive function. 

{

while(RI==0);                                 // Wait while receive flag is not high.   

RI=0;                                               // Reset the receive flag.

return SBUF;                                   // Return data received in SBUF.

} 

void rx_word(unsigned int len)   // receive  function to store character in array

{

int i;                                     // integer i     

for(i=0;i<len;i++)              // for loop until string user defined length is reached.

{

p[i]=rx();                     // Receive function. 

}

}

  :  Circuit Diagram

A terminal window is connected to microcontroller 

for serial comm. 

 

 RxD of  8051 is connected to TxD of terminal.

TxD of  8051 is connected to RxD of terminal.

String Output Results : 

Here the word you type will be displayed at once, once the string length is reached .