Interface a GPS module with 8051 extract the RMC data and display on 16×2 lcd

[Tyrone]

I’m trying to build up a sort of a GPS trecker using the SkyNave SKM53 gps module and interface it with the 89C51AC2 microcontroller. I’ve tried of all sort and thanks to this site I made up lots of improvement. Here I found a project that is similar to what I want to biuld, here’s the link: 

http://www.engineersgarage.com/microcontroller/8051projects/extract-gps-receiver-details-8051-circuit

I’ve done the same programming as I found here but I changed the output pins of the lcd instead of P2 I used P0 but the lcd dispaly nothing. Now I’m trying to just display the date so at least I can begin from somewhere I have diplayed “DATE” on the fist line and on the second line the result is something like this %%-%%-%% .  Below is the program of what I’ve done so far could someone please help me to extract the correct date please…

 

 

 

 

#include<reg51.h>

 

char info[70];

char test[6]={“$GPRMC”};

char comma_position[13];

unsigned int check=0,i;

unsigned char a;

 

void lcd_data (unsigned int i);

void lcd_cmd(unsigned int i);

void delay(int j);

void initialise_lcd();

void lcd_date();

void serial();

void find_comma();

void lcd_string();

 

// SERIAL PORT SETTING

void serial()

{    

TMOD=0x20;     //MODE=2    

TH1=0xFD;       // 9600 BAUDRATE    

SCON=0x50  ;   // SERIAL MODE 1 ,8- BIT DATA ,1 STOP BIT ,1 START BIT , RECEIVING ON    

TR1=1;           //TIMER START

}

 

void receive_data()            interrupt 4 

{    

info[check++]=SBUF;       //Read SBUF

if(check<7)    

{        

if(info[check-1]!=test[check-1])        

check=0;    

}    

RI=0;

}

 

void main()

{   

serial();

   

while(1)    

    {           

find_comma();

lcd_date();    

}

}

 

// Send the begining commads – Always

void initialise_lcd()  

{

 

    lcd_cmd(0x38);   //init. LCD 2 lines,5×7 matrix

    delay(1000);

    lcd_cmd(0x0e); //display on, cursor on

    delay(1000);

    lcd_cmd(0x01); //clear lcd

    delay(1000);

    lcd_cmd(0xc0); //cursor

    delay(1000);

}

 

// Sending Command To LCD

void lcd_cmd(unsigned int i)

{   

P0 = i  ;

    P2 =  0X04;   //rs = 0, rw = 0, e = 1

    P2 = 0X00;   //clear enable to make pulse

}

 

// Sending Data To LCD

void lcd_data (unsigned int i)

{   

P0 = i ;

    P2 =  0X05; //rs = 1, rw = 0, e = 1

    P2 = 0X01; //clear enable to make pulse

}

 

void lcd_date()

{    

unsigned int c9=comma_position[8];

unsigned char i =0;

char write[] = “DATE”;

initialise_lcd();

 

lcd_cmd(0x80);

for(i=0; i<4; i++)

{

delay(1000);

lcd_data(write);

}

delay(1000);

lcd_cmd(0xC0);

delay(1000);    

lcd_data(info[c9+1]);

delay(1000);    

lcd_data(info[c9+2]);

delay(1000);    

lcd_data(‘-‘);

delay(1000);    

lcd_data(info[c9+3]);

delay(1000);    

lcd_data(info[c9+4]);

delay(1000);    

lcd_data(‘-‘);

delay(1000);    

lcd_data(info[c9+5]);

delay(1000);    

lcd_data(info[c9+6]);    

delay(1000);

 

while(1);

}

 

//DELAY FUNCTION

void delay(unsigned char i)

{   

  unsigned int rr;

    for (rr = 0; rr < i; rr++);

}

 

void find_comma()

{    

unsigned int i,count=0;    

for(i=0;i<70;i++)    

{            

if(info==’,’)        

{            

comma_position[count]=i;        

} 

}

}

 

 

 

Thanks 

Tyrone

 

[praveen]

i  have problem in inerrupt 4……the value from gps is not  matching with the test array…..what should be done

[Author]

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