serial data is not receiving by 8051 micro controller

[V L RAGHURAM]

Hi friends, i am new to this forum, i have encountered a problem, i want to send the serial data from PC to 8051 micro controller through serial port and hyper terminal software, but the data is not receiving by micro controller. I want to display the character on 16 x 2 LCD display. RI is not setting to 1 and the routine what i written to receive and display the character is not executing. I am using Flash magic software to dump the code into micro controller and it is going properly. 

 

Since one week i am facing this problem, earlier it worked properly(data displayed on LCD). I attached my code and circuit diagram, so please suggest me what to do.

#include <REGX51.H>

 

 

sbit rs = P3^7;

sbit rw = P3^5;

sbit en = P3^6;

 

void msdelay(unsigned int value)

{   

unsigned int i,j;

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

for(j=0;j<1275;j++);

}

 

void LCD_data(unsigned char x)

{

 

 rs=1;

 rw=0;

 P1=x;

 en=1;

 msdelay(6);

 en=0;

 msdelay(6);

}

 

void LCD_cmd(unsigned char x)

{

  

  rs=0;

  rw=0;

  P1=x;

  en=1;

  msdelay(6);

  en=0;

  msdelay(6);

}

 

void lcd_str(unsigned char *str)

{

 int x;

 for(x=0;str[x]!=0;x++)

  {

    LCD_data(str[x]); 

  }

}

 

void lcd_ini()                  //Function to initialize the LCD

{

    LCD_cmd(0x38);          

    msdelay(5);

    LCD_cmd(0x0F);        

    msdelay(5);

    LCD_cmd(0x80);

    msdelay(5);

}

 

/* this headder file having the functions

serialinit()

tx(hex value) 

txs(string)

rx()

 

*/

void serialinit()   //serialinitilization

{

TMOD=0x20;// timer1,mode2

SCON=0x50;

TH1=-3;

TR1=1;

}

void tx(unsigned char ch) //transmitting a single charecter

{

SBUF=ch;

while(TI==0);  //wait until TI=1

TI=0;

}

void txs(unsigned char *chr) //to send a string

{

unsigned char i=0;

for(i=0;chr!=’’;i++)

tx(chr);

}

unsigned char rx()  //serial receiving

{

unsigned char ch;

while(RI==0);

ch=SBUF;

RI=0;

LCD_cmd(0x01);

LCD_data(ch);

}

 

 

 

 

 

void main()   

{

serialinit();

lcd_ini();

txs(“testing string”);

lcd_str(“Raghuram”);

while(1)

{

rx();

}

  

 

}

[AJISH ALFRED]

Hi Raghuram,

RI and TI are bits, right? so try

 

“while ( RI = 0 );” and “while ( TI = 0 );” instead of “while ( RI == 0 );” and “while ( TI = 0 );”

[Ashutosh Bhatt]

there must be a problem in your baud rate. it wont be same on both side

set 9600 baud rate in your hyper terminal software (or flash magic or tera term) in PC

to set 9600 baud in your 8051 use 11.059 MHz crystal. and calculate proper value to load in timer registers.

[SHAH DISHANT H.]

Hi,

 

Have you checked with baud rate?

 

Set the same baudrate on both side and check it.

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