RCB-4H GPS module interface with PIC 16F877A

[soneal]

GPS and PIC 16F877A

Hi everyone.
I need some help.my final year project is about a velocity meter with GPS module.
I have GPS module (u-blox RCB-4H) ,PIC 16F877A and LCD display.
Firstly how can i interface the PIC and GPS module? Should i put something between them while interfacing?
Then, any code example do you have?.
I am new about this equipment and please help me or any adveice as soon as possible. because my time is restricted :S
Thank you.
(I add the datasheet of RCB-4H GPS module)

 

[NOORPURI]

Just Simply connect TX of GPS RCVR to RX of Microcontroller. And for time Tick accuracy connect GPS TP to interrupt pin of Microcontroller

 

[soneal]

thank you so much noorpuri
then i have interface the PIC with LCD display.do i need any circuit connection between PIC and LCD?

 

[soneal]

Hi again )
I had quited to work on this project but i am trying to do again now. I have made progress about circuit and code. However i need your help about with my code. I wrote this code in CCS C software. here it is:



#include <16F877A.h>
#fuses HS,NOWDT,NOPROTECT,NOBROWNOUT,NOLVP,NOPUT,NOWRT,NODEBUG,NOCPD
#device *=16 // This enables use of all RAM.
#use delay (clock=20000000)
#use fast_io(b)
#define use_portb_lcd TRUE
#include<lcd.c>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#use rs232(baud=9600, xmit=PIN_c6, rcv=PIN_c7, parity=N, bits=8, ERRORS)
#define BUFFER_SIZE 96

BYTE buffer[BUFFER_SIZE]; // implemented as a circular buffer

int comma = 0;
int dataLen;
int start, end, speedLen=0;
int i;
char speed[10];
char c;

short ReadSerial = 0;
short startok = 0;
int8 index,x;


double parseData() // this function parses the $GPVTG data strings to find the speed information
{
dataLen = strlen(buffer);
for (i=0; i<dataLen; i++)
{
if (buffer == ',')
comma++;
if (comma == 7)
{
i++;
start = i;
while (buffer != ',')
{
speedLen++;
i++;
}
end = i-1;
break;
}
}

for (i=start; i<=end; i++)
{
speed[i-start] = buffer;
}
speed = '\0';
return atof(speed);
}


#int_rda
void gps_isr()
{/// note this routine needs to as short as possible since it is called
/// for each char received from GPS

c=getc() ;

putc(c);
if (c=='$')
{
index = 0;
startok = 1;
}
buffer[index] = c;
index++;
if (index>BUFFER_SIZE)
{
index = 0;
}
if ((index>62) && (startok==1) && (buffer[3]=='V') && (buffer[4]=='T') && (buffer[5]=='G'))
{
startok=0;
disable_interrupts(int_rda);
readserial = 1;
}
}

#separate
void reset_serial()
{
ReadSerial = 0;
index = 0;
for(x=0;x<BUFFER_SIZE;x++) buffer[x]=' '; // reset input buffer
enable_interrupts(int_rda);
}


int main(){

setup_psp(PSP_DISABLED);
setup_spi(FALSE);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED, 0, 1);
setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_OFF);
setup_CCP1(CCP_OFF);
setup_CCP2(CCP_OFF);

enable_interrupts(GLOBAL);

reset_serial();

set_tris_b(0x00); // set the b port to the output



while(1)
{

if ( readserial == 1 )

{

lcd_init(); // initialize the lcd
lcd_send_byte(0,0x0d);
lcd_gotoxy(1,2);
printf(lcd_putc,"\f SPEED = %f",parseData());
delay_ms(1000);

reset_serial();

}

}
}

 

[layth amleh]

good evening everyone.
I need some help in my final year project GPS module.
I have GPS module (gps-310fs) ,PIC 16F877A and LCD display.
Firstly how can i interface the PIC and GPS module?
i need schematic design to connect gps with pic 16f877a