LCD 4 bit

/* P0 noi voi LCD data*/
/* ma tran phim noi voi P3*/
/* noi 4 bit thap cua P2 voi chan cam LCD_CONTROL*/

/* cac lenh su dung:
int_lcd(); cai dat lcd
lenh(clr); xoa lcd
lenh(home); dua con tro ve dau dong
lenh(d_on); mo display,blink
lenh(set); che do 16x2
dat(1 ki tu); xuat 1 ki tu ra lcd
dat_str("chuoi"); xuat 1 chuoi ki tu ra lcd
*/

#include
const unsigned char clr=1,home=2,d_on=15,set=56,d_off=12;
sbit rs=P2^0; //P2_0
sbit rw=P2^1; //P2_1
sbit e=P2^2; //P2_2
sbit li=P2^3; //P2_3

//chuong trinh con tao thoi gian tre
void delay(unsigned int time)
{
unsigned int x,y;
for(x=0;x {
for(y=0;y<33;y++);
}
}
//-------------------------------------------------------

//chuong trinh con kiem tra lcd co ban ko
void busy()
{
rs=0;
rw=1;
P0_7=1;
while(P0_7!=0)
{
e=0;
e=1;
}
}
//--------------------------------------------------------

//chuong trinh con xuat lenh len LCD
void lenh(unsigned char ma)
{
busy();

rs=0;
rw=0;
e=1;
P0=ma;
e=0;
}
//---------------------------------------------------------

//chuong trinh con xuat du lieu len LCD
void dat(unsigned char ma)
{
busy();

rs=1;
rw=0;
e=1;
P0=ma;
e=0;
}
//----------------------------------------------------------

//chuong trinh di chuyen con tro
void mov(unsigned char row, unsigned char col)
{
lenh(128 | (row << 6) | col); //row =0 la hang dau,=1 la hang 2
}
//---------------------------------------------------------

//chuong trinh xuat ra LCD mot chuoi ki tu
void dat_str(unsigned char *str)
{
while (*str!='\0')
{
dat(*str);
str++;
}
}
//----------------------------------------------------------

//chuong trinh con cai dat LCD
void int_lcd()
{
delay(30); //doi
lenh(set); //8bit, 2 line
//lenh(d_on); //display on, cursor on,blinking on
lenh(d_off); //display on,cursor off,blinking off
lenh(clr); //clear display
lenh(home); //return home
}