LCD_51

#include <reg51.h>
#define keyboard  P3
#define dbport P0
sbit RS=P2^7;
sbit RW=P2^6;
sbit E=P2^5;

void debouncer();
unsigned char num[] = {0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0x41,0x42,0x43,0x44,0x45,0x46};
unsigned char scan[4] = {0xef,0xdf,0xbf,0x7f};
void delay1ms(int);
void lcd_data(char data1);
void lcd_cmd(char cmd);
void init_lcd();
char line1[]="welcome";
void main(void)
{
    unsigned char col,row,press,kcode,key_line2,key_line1,key_count;
    key_count=1;
    key_line2=0xc0;
    key_line1=0x80;
    lcd_cmd(0x3f);
    lcd_cmd(0x0e);
    lcd_cmd(0x01);
    delay1ms(5);
    lcd_cmd(0x80);
    //char *pp;
    while(1)
    {
        for(col=0;col<4;col++)
        {
            keyboard=scan[col];
            press=~keyboard&0x0f;
            if(press!=0)
            {
                debouncer();
                if(press==0x01) row=0;
                else if(press==0x02) row=1;
                else if(press==0x04) row=2;
                else if(press==0x08) row=3;
                kcode=row+4*col;
                while(press!=0)
                    press=~keyboard&0x0f;
                debouncer();

                if(key_count==33)
                {
                    key_count=1;
                    lcd_cmd(0x01);
                    delay1ms(5);
                    if(key_count<=16)
                    {
                    lcd_cmd(key_line1);
                    lcd_data(num[kcode]);
                    key_line1=key_line1+0x01;
                        if(key_count==16)key_line1=0x80;
                    }
                    else if((key_count<=32)&&(key_count>=17))
                    {
                    lcd_cmd(key_line2);
                    lcd_data(num[kcode]);
                    key_line2=key_line2+0x01;

                        if(key_count==32) key_line2=0xc0;
                    }
                }
                else
                {
                    if(key_count<=16)
                    {
                    lcd_cmd(key_line1);
                    lcd_data(num[kcode]);
                    key_line1=key_line1+0x01;
                        if(key_count==16)key_line1=0x80;
                    }
                    else if((key_count<=32)&&(key_count>=17))
                    {
                    lcd_cmd(key_line2);
                    lcd_data(num[kcode]);
                    key_line2=key_line2+0x01;

                        if(key_count==32) key_line2=0xc0;
                    }
                }
                key_count=key_count+1;
            }


        }
    }

}
void delay1ms(int x)
{
    int i, j;
    for(i=0;i<x;i++)
        for(j=0;j<114;j++);
}
void debouncer()
{
    delay1ms(20);
}
void lcd_data(char data1)
{
    char i;
    dbport=data1;
    RS=1;RW=0;E=1;
    for(i=0;i<40;i++)
    RS=1;RW=0;E=0;
}
void lcd_cmd(char cmd)
{
    char i;
    dbport=cmd;
    RS=0;RW=0;E=1;
    for(i=0;i<40;i++)
    RS=0;RW=0;E=0;
}
void init_lcd()
{
    lcd_data(0x30);
    lcd_data(0x30);
    lcd_data(0x30);
    lcd_data(0x38);
    lcd_data(0x08);
    lcd_data(0x01);
    lcd_data(0x06);
    lcd_data(0x0c);
}