Help with serial communication and lighting of led

[Julian]

Greetings. I’m a beginner is programming 8051. i’m doing a project involving leds, pushbuttons, lcd n serial comm. My led, lcd and pushbuttons work fine but when i combined the serial part, it’s only either the serial is working or the lcd n led are working. I’ve provided my source code below. it’s not a difficult program. pls correct me if there’s any mistake. thx a lot. 

 

 

 

 

#include <reg51.h>

#include <stdio.h>

#define lcd_port P2

 

int j;

sbit rs = P0^5;

sbit rw = P0^6;

sbit en = P0^7;

sbit BUT0 = P0^0;

sbit LED0 = P1^0;

sbit BUT1 = P0^1;

sbit LED1 = P1^1;

 

char bz[]={“Busy”};

char awy[]={“Not at campus”};

 

void delay(unsigned int msec)  

{

int i,j ;

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

for(j=0;j<200;j++);

}

 

void lcdcmd(unsigned char value)

{

rs = 0;

rw = 0;

lcd_port = value;

en = 1;

delay(1);

en = 0;

}

 

void lcd_data(unsigned char display)

{

rs = 1;

rw = 0;

lcd_port = display;

en = 1;

delay(1);

en = 0;

}

 

void shift_left()

{

lcdcmd(0x18);

delay(200);

}

 

void lcd_busy()

{

for (j=0; bz[j]!=’’;j++)

{

  lcd_data(bz[j]);

  delay(100);

}

}

 

void lcd_away()

{

for (j=0; awy[j]!=’’;j++)

{

  lcd_data(awy[j]);

  delay(100);

}

}

 

void lcd_init()

{

lcdcmd(0x38);

delay(150);

lcdcmd(0x0E);

delay(150);

lcdcmd(0x01);

delay(150);

lcdcmd(0x06);

delay(150);

lcdcmd(0x80);

delay(150);

}

 

void main(void)

{

lcd_init();

 

while(1)

{

if(!BUT0)

{

LED0 = 0;

LED1 = 1;

lcdcmd(0x01);   

delay(50);

   lcd_busy();

}

else if(!BUT1)

{ 

LED0 = 1;

LED1 = 0;

lcdcmd(0x01);

delay(50);

   lcd_away();

}

else if ( BUT0 && BUT1)            // serial part

{

char word;

TMOD = 0x20;

TH1 = 0xFD;

SCON = 0x50;

TR1 = 1;

while (RI == 0);

word = SBUF;

lcd_data(word);

RI = 0;

}

else

{

shift_left();

}

}

}

[GANEEV SINGH]

Hi

One thing that I think could be a problem in this code is that Timer1 is being initailized everytime you try to receive a byte. Initialization should be done once throughout the communication process. Try refering this project on EG: https://www.engineersgarage.com/microcontroller/8051projects/interface-serialport-RS232-AT89C51-circuit

[Author]

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