GPS INTERFACING

#include  <lpc214x.h>     //Includes LPC2148 register definitions
#include <string.h>
#define DATA_PORT() IO0SET=(1<<16)       //Function to select data port on LCD
#define READ_DATA() IO0SET=(1<<17)       //Function to select read operation on LCD
#define EN_HI() IO0SET=(1<<18)           //Function to Enable LCD


#define COMMAND_PORT() IO0CLR=(1<<16)     //Function to select command port on LCD
#define WRITE_DATA() IO0CLR=(1<<17)       //Function to select write operation on LCD
#define EN_LOW() IO0CLR=(1<<18)           //Function to disable LCD

unsigned char String1[16]={"NORTH"};
unsigned char String2[16]={"EAST"};
unsigned char String3[16]={"WEST"};
unsigned char String4[16]={"SOUTH"};

 char direction1[] = "North";
 char direction2[] = "East";
 char direction3[] = "West";
 char direction4[] = "South";

void Delay(unsigned char j)
{
 unsigned int  i;
 for(;j>0;j--)
 {
  for(i=0; i<60000; i++);
 }
}

void Delay_Small(unsigned char j)
{
 unsigned int  i;
 for(;j>0;j--)
 {
  for(i=0; i<1000; i++);
 }
}


unsigned char Busy_Wait()              //This function checks the busy status of LCD
{
 unsigned int temp=0;
 EN_LOW();
 COMMAND_PORT();
 READ_DATA();

 IO0PIN&=0xFF87FFFF;
 IO0DIR&=0xFF87FFFF;
 IO0PIN|=0x00400000;

 do{
 EN_HI();
 EN_LOW();
 EN_HI();
 EN_LOW();
 temp=IO0PIN;
 }
 while((temp & 0x00400000)==0x00400000);
 EN_LOW();
 WRITE_DATA();
 IO0DIR&=0xFF80FFFF;
 IO0DIR|=0x007F0000;
 return (0);
}


void LCD_Command(unsigned int data)           //This function is used to send LCD commands
{
 unsigned int temp=0;
 EN_LOW();
 COMMAND_PORT();
 WRITE_DATA();

 temp=data;
 //IO0PIN&=0xFF87FFFF;
 IO0PIN&=0x00010000;
 IO0PIN|=(temp & 0xF0) << 15;

 EN_HI();
 EN_LOW();

 temp=data & 0x0F;
 //IO0PIN&=0xFF87FFFF;
 IO0PIN&=0x00010000;
 IO0PIN|=(temp) << 19;

 EN_HI();
 EN_LOW();
 //while(Busy_Wait());
 Delay(10);
}


void LCD_Data(unsigned int data)           //This function is used to send data to LCD
{
 unsigned int temp=0;
 EN_LOW();
 DATA_PORT();
 WRITE_DATA();

 temp=data;
 //IO0PIN&=0xFF87FFFF;
 IO0PIN&=0x00010000;
 IO0PIN|=(temp & 0xF0) << 15;

 EN_HI();
 EN_LOW();

 temp=data & 0x0F;

 //IO0PIN&=0xFF87FFFF;
 IO0PIN&=0x00870000;
 IO0PIN|=(temp) << 19;

 EN_HI();
 EN_LOW();
 Delay_Small(1);
}

void LCD_Init()
{
 LCD_Command(0x02);
 LCD_Command(0x28);
 LCD_Command(0x0C);
 LCD_Command(0x06);
}


void LCD_String(unsigned char *data)
{
 while(*data)
 {
  LCD_Data(*data);
  data++;
 }
}


int main(void)
{
 PINSEL0 = 0x00000000;      // Enable GPIO on all pins
 PINSEL1 = 0x00000000;
 PINSEL2 = 0x00000000;

 Delay(20);
 IO0DIR = (1<<22) | (1<<21) | (1<<20) | (1<<19) | (1<<18) | (1<<17) | (1<<16);


 LCD_Init();
 LCD_Command(0x01);
 Delay(20);


 while(1){
 char dir[]="North";               //change directions
        LCD_Command(0x01);
 if(strcmp(dir,direction1)== 1){
      LCD_Command(0x80);
        LCD_String(&String1[0]);
 }else if(strcmp(dir,direction2)== 1){
      LCD_Command(0x80);
        LCD_String(&String2[0]);
 }else if(strcmp(dir,direction3)== 1){
      LCD_Command(0x80);
        LCD_String(&String3[0]);
 }else if(strcmp(dir,direction4)== 1){
      LCD_Command(0x80);
        LCD_String(&String4[0]);
 }
 }
}