Serial data reception using 8051

SOFTWARE: KEIL MICRO VISION 4.0

SIMULATOR: PROTEUS 8.0

CIRCUIT DIAGRAM:

WORKING:

Here in this project, I have received the data from the virtual terminal and displayed the received data on an lcd.When all the data get received, the RI flag in the SCON register becomes equal to 1 which indicates the complete reception of data(8 bit).

Received data gets stored into the SBUF register. I have taken the received data from the SBUF register and send this data on an lcd. I have used a 9600 baud rate.All the serial communication is done using TXD and RXD pin of 8051.

PROGRAM:

#include<reg51.h>

sbit RS = P2^0; 

sbit EN = P2^2;

void lcd_init(void); // lcd initialization function

void lcd_command(unsigned char c);// lcd command function

void lcd_data(unsigned char d);// lcd data function

void delay(unsigned int t); // delay function

int main()

{

unsigned char r;

lcd_init(); // lcd initialization

TMOD=0x20; // timer 1 in mode 2

SCON=0x50; // mode 1,8 bit data,1 stop bit,1 start bit

TH1=0xfd; // 9600 baud rate

TR1=1; // start timer 1

RI=0;   // clear receive flag

while(1)

{

while(RI==0); // wait untill reception is complete

r = SBUF;

RI=0; // clear RI for next reception

if(r==8)   // if backspace is pressed

{

lcd_command(0x01); // clear display

}

else

{

lcd_data(r); // display the received data on an lcd

}

}

}

void lcd_init()

{

lcd_command(0x01); // clear display

lcd_command(0x06); // Entry mode

lcd_command(0x38);//8 bit mode,2 line,5x7 matrix

lcd_command(0x0c); // display on,cursor off

lcd_command(0x80); // first location(begining)

}

void lcd_command(unsigned char c)

{

P1=c;

RS=0; // select command register

EN=1;  // send high to low pulse on enable pin

delay(2);

EN=0;

delay(4);

}

void lcd_data(unsigned char d)

{

P1=d;

RS=1; // select data register

EN=1;  // send high to low pulse on enable pin

delay(2);

EN=0;

delay(4);

}

void delay(unsigned int t)

{

unsigned int i;

for(i=0;i<t*1240;i++);

}

PROGRAM DESCRIPTION:

First I have initialized the lcd. After that I have followed the steps mentioned below.

Steps for serial data reception in serial mode 2:

1.Set the timer 1 in mode 2.

2.Set the SCON register in mode 2 with REN bit enable.

3.Select the baud rate and send the data with respect to that baud rate to TH1 register(as mentioned in above table). 
4.Start the timer 1.
5.Clear the RI flag.
6.Wait for the RI flag to set 1.

7.Take the data from the SBUF register.
8.Clear the RI flag to receive the next data.
9.For continuous process, repeat from step 6.

For selecting the baud rate send the below data to the TH1 register.

Whatever data we typed on the virtual terminal that data will get displayed on an lcd. Pressing of backspace key will clear the lcd screen.

VIDEO: