void init_port();
void data(char);
void control(char);
void dely(long);
void init_lcd();
void write_data(char);
void write_command(char);
void write_string(char);
void create_char(char location, volatile char array1[]);
void write_char(char);
void write_userchar();

void setup() {
   volatile char userchars[4][8] = {
    {0x00, 0x0A, 0x0A, 0x00, 0x11, 0x0E, 0x00, 0x00},
    {0x00, 0x0A, 0x1F, 0x1F, 0x0E, 0x04, 0x00, 0x00}, 
    {0x00, 0x04, 0x0E, 0x1F, 0x0E, 0x04, 0x00, 0x00}, 
    {0x00, 0x0E, 0x11, 0x11, 0x11, 0x0E, 0x00, 0x00}};

  init_port();
  init_lcd();
  for (char i = 0; i < 4; i++) {
    create_char(i, userchars[i]);
  }
  write_command(0x80); //set ddram address 0
  write_userchar();
  write_string(" LCD ");
  write_userchar();
  dely(1500);
  init_lcd();
  write_command(0x84); //custom address of 1st line
  write_string("HELLO...");
  write_command(0xc0); //custom address of 2nd line
  write_string("Welcome to Earth");
  write_command(0x0c); //turn cursor and blink off
  while(1){
    write_command(0x18); //shift display to left
    dely(50);
  }
}

void init_port(){
  volatile char *Fdir=(volatile char *)0x30, *Kdir=(volatile char *)0x107; 
  *Fdir=0x03; *Kdir=0xff;
}
void data(char ad1){
  volatile char *Kout=(volatile char *)0x108;
  *Kout=ad1;
}
void control(char ad2){
  volatile char *Fout=(volatile char *)0x31;
  *Fout=ad2;
}
void dely(long ms){
  for(volatile long g=0; g<(ms*1000); g++);
}

void write_data(char let){
  data(let);
  control(0x02); //RS=1
  dely(1);
  control(0x03); 
  dely(1);
  control(0x02);
  dely(1);
}
void write_command(char adr){
  data(adr);
  control(0x00); //RS=0
  dely(1);
  control(0x01); 
  dely(1);
  control(0x00);
  dely(1);
}
void init_lcd(){
  write_command(0x38); //8 bit 2 line
  write_command(0x0c); //cursor off
  write_command(0x01); //clear disp
  write_command(0x06); //cursor moves right without shift
}
void write_string(char *name) { 
  while (*name != '\0') {
    write_data(*name);
    dely(5);
    name++;
    }
}
void create_char(char location, volatile char array1[]) {
  for (volatile char j = 0; j < 8; j++) {
    write_command(0x40 + (location * 0x08) + j);
    write_data(array1[j]);
  }
}
void write_char(char location){
  write_command(0x80);
  write_data(location);
}
void write_userchar(){
  for (volatile char i = 0; i < 4; i++) {
    write_data(i);
    dely(50);
  }
}