Interfacing parallax Gps Receiver

GtsTsgy

Hi everybody, I bought parallax Gps Receiver Rev 2.3 last month. I want to interface it with 80c51 Phillips microcontroller read standard NMEA0183 data and display it in 4x20 lcd. but nothing is displayed in the lcd.
the type of gps i used is
http://www.grandideastudio.com/portfolio/gps-receiver/
and its datasheet is
http://www.parallax.com/dl/docs/prod/acc/GPSManualV1.1.pdf
my code is

#include "lcd.h" //lcd header file
bit datareceived = 0;
unsigned char Data;

/******************************************************************************/
void serial_init() //setting baudrate at 4800
{
PCON= 0x80;
TMOD = 0x20;
SCON = 0x50;
TH1 = (unsigned char)(256-(12000000/(12 * 16 * 4800)));
TR1 = 1;
}

/******************************************************************************/
void serial_read() interrupt 4 using 2
{

if (RI)
{
Data = SBUF;
RI = 0;
datareceived = 1;
}
}


/*************************************************************/
void main()
{
char ch,x=0;
lcdInit();
serial_init();
EA = 1;
ES = 1;

lcdClear();
lcdGotoXY(1,0);
lcdPrint("Communication");
RAM = 0;
while(1)
{
if(datareceived)
{
datareceived=0;
lcdGotoXY(x++,1);
sprintf(ch,"%c", Data);
lcdPrint(ch);
}
}
}
/*************************************************************/

hover1

Are you running the GPS in RAW mode? (Pin 4 low)

Franklin

First make sure you can display text on the LCD. You will have to find code elsewhere. Then make sure you are getting data from the GPS, hook it up to your computer and see if it is sending data. Now you can connect the two in your code.

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- Stephen

GtsTsgy

Thanking Stephen and ---- for your help.

Yes, I am running in RAW mode. And I do not have problems in displaying data on the 4x20 LCD

GtsTsgy

TH1 = (unsigned char)(256-((12000000/192)/ 4800));

Franklin

I would do the math on a calculator and plug that number into the equation.

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- Stephen