Adam

This is the code that I use to check the LCD
On some LCD's you have to pulse the clock to get the busy signal,so this code will work on most HD44780 and clones.Note that is uses 4 bit mode through port 0 with pullups.



do { // wait until lcd is ready
lcd_port =0xf0;//set upper nibble to input
lcd_rw = 1;
lcd_enable = 1; // toggle data clock
delay_us();
lcd_val = lcd_port; // read data bus
lcd_enable = 0;
delay_us();
lcd_enable = 1;
lcd_short_delay();
lcd_enable = 0;

} while(lcd_val & 0x80);//keep looping if DB7 set,clears when not busy



the initialisation code is


void init_lcd(void) {
U8 i;
lcd_port=0;

lcd_long_delay();

for(i=1;i<=3;++i) {
lcd_port=0x30;
delay_ms(10);
lcd_enable = 1;
lcd_short_delay();
lcd_enable = 0;

}

lcd_port=0x20;
lcd_long_delay();
lcd_enable = 1;
lcd_short_delay();
lcd_enable = 0;
lcd_long_delay();

lcd_send_byte(1,0x28);
lcd_long_delay();
lcd_send_byte(1,0x08);
lcd_long_delay();
lcd_send_byte(1,0x0c);
lcd_long_delay();
lcd_send_byte(1,0x06);
}