Interface GPS with PIC18F4550 Microcontroller

[KOH YUEN KHANG]

// Program to Interface GPS with PIC18F4550 Microcontroller

#include <xc.h>

#include <p18f4550.h>

 

#define FREQ 12000000 #define baud 4800 #define spbrg_value (((FREQ/64)/baud)-1) #define rs LATA.F0 #define rw LATA.F1 #define en LATA.F2 #define lcdport LATB

unsigned char rx_data();
void lcd_ini();
void lcdcmd(unsigned char);
void lcddata(unsigned char);

unsigned char longi_data[12];
unsigned char lati_data[12];
unsigned char data,value=0;
unsigned int i=0,pos;

void main()
{
TRISB=0; // Set Port B as output port
LATB=0;
TRISA=0;
LATA=0;
SPBRG=spbrg_value; // Fill SPBRG register to set the baud rate
RCSTA.SPEN=1; // To activate serial port (Tx and Rx pins)
RCSTA.CREN=1; // To enable continuous reception
lcd_ini();
while(1)
{
data=rx_data(); // Check the string '$GPGGA,'
if(data=='$')
{
data=rx_data();
if(data=='G')
{
data=rx_data();
if(data=='P');
{
data=rx_data();
if(data=='G');
{
data=rx_data();
if(data=='G')
{
data=rx_data();
if(data=='A')
{
data=rx_data();
if(data==',')
{
data=rx_data();
while(data!=',')
data=rx_data();
for(i=0;data!='N';i++)
data=rx_data();
lati_data=data; // Store the Latitude data
}
data=rx_data();
if(data==',')
{
for(i=0;data!='E';i++)
{
data=rx_data();
longi_data=data; // Store the Longitude data
}
}
i=0;
lcdcmd(0x80);
while(i<11)
{
lcddata(lati_data); // Print the Latitude data
i++;
}
i=0;
lcdcmd(0xC0);
while(i<12)
{
lcddata(longi_data); // Print the Longitude data
i++;
}
}
}
}
}
}
}
}
Delay_ms(1000);
for(i=0;i<12;i++)
{
data=0;
lati_data=0;
longi_data=0;
}
}
}

unsigned char rx_data(void)
{
while(PIR1.RCIF==0); // Wait until RCIF gets low
return RCREG; // Store data in Reception register
}

void lcd_ini()
{
lcdcmd(0x38); // Configure the LCD in 8-bit mode, 2 line and 5×7 font
lcdcmd(0x0C); // Display On and Cursor Off
lcdcmd(0x01); // Clear display screen
lcdcmd(0x06); // Increment cursor
lcdcmd(0x80); // Set cursor position to 1st line, 1st column
}

void lcdcmd(unsigned char cmdout)
{
lcdport=cmdout; //Send command to lcdport=PORTB
rs=0;
rw=0;
en=1;
Delay_ms(10);
en=0;
}

void lcddata(unsigned char dataout)
{
lcdport=dataout; //Send data to lcdport=PORTB
rs=1;
rw=0;
en=1;
Delay_ms(10);
en=0;
}

 

I obtanied the code above from the link below:

http://www.engineersgarage.com/embedded/pic-microcontroller-projects/gps-interface-circuit

I'm using MPlab IDE with xc8 compiler to run this code but I encountered the error below:

Executing: "C:Program FilesMicrochipxc8v1.35binxc8.exe" –pass1 "C:UsersHui YiDesktoppic18f4550test.c" -q –chip=18F4550 -P –runtime=default –opt=default -N-1 -D__DEBUG=1 -g –asmlist "–errformat=Error   [%n] %f; %l.%c %s" "–msgformat=Advisory[%n] %s" "–warnformat=Warning [%n] %f; %l.%c %s" 

Error   [196] C:UsersHui YiDesktoppic18f4550test.c; 29.11 struct/union required

Error   [196] C:UsersHui YiDesktoppic18f4550test.c; 30.11 struct/union required

Warning [361] C:UsersHui YiDesktoppic18f4550test.c; 92.1 function declared implicit int

Error   [285] C:UsersHui YiDesktoppic18f4550test.c; 100.1 no identifier in declaration

Warning [374] C:UsersHui YiDesktoppic18f4550test.c; 100.1 missing basic type; int assumed

Error   [314] C:UsersHui YiDesktoppic18f4550test.c; 100.1 ";" expected

Error   [196] C:UsersHui YiDesktoppic18f4550test.c; 104.16 struct/union required

Error   [196] C:UsersHui YiDesktoppic18f4550test.c; 120.8 struct/union required

Error   [196] C:UsersHui YiDesktoppic18f4550test.c; 121.8 struct/union required

Error   [196] C:UsersHui YiDesktoppic18f4550test.c; 122.8 struct/union required

Error   [196] C:UsersHui YiDesktoppic18f4550test.c; 124.8 struct/union required

Error   [196] C:UsersHui YiDesktoppic18f4550test.c; 130.8 struct/union required

Error   [196] C:UsersHui YiDesktoppic18f4550test.c; 131.8 struct/union required

Error   [196] C:UsersHui YiDesktoppic18f4550test.c; 132.8 struct/union required

Error   [196] C:UsersHui YiDesktoppic18f4550test.c; 134.8 struct/union required

(908) exit status = 1

 

Can anyone tell me whats wrong with this code or any things i have to add with?

 

[Prabakaran P M]

Hi KOH YUEN KHANG,

Copy the code from the page exactly as it is and make it look like same in the page use HitechC compiler.

[Author]

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