#include <string.h>

volatile char *DDR_DATA = (volatile char *)0x30;
volatile char *DDR_COMM = (volatile char *)0x107;

volatile char *PORT_DATA = (volatile char *)0x31;
volatile char *PORT_COMM = (volatile char *)0x108;

#define EN  0
#define RS  1
#define EN_HIGH  *PORT_COMM |=  (1<<EN);
#define EN_LOW   *PORT_COMM &= ~(1<<EN);
#define RS_HIGH  *PORT_COMM |=  (1<<RS);
#define RS_LOW   *PORT_COMM &= ~(1<<RS);

void delay1(int i){
  delayMicroseconds(2);
}
void init_port(void){ 
  *DDR_DATA = 0xFF; //8-pins
  *DDR_COMM = 0x03; //2-pins
}
void outcommand(char comm){
  //*PORT_DATA = data;
  *PORT_DATA = (*PORT_DATA &0xF0) |((comm >> 4) & 0x0F);
  RS_LOW;
  EN_pulse();
  delayMicroseconds(1);
  *PORT_DATA = (*PORT_DATA & 0xF0 ) |(comm & 0x0F);
  RS_LOW;
  EN_pulse();
  delayMicroseconds(2);
  //delayMicroseconds(100);
}
void outdata(char data){
  //*PORT_DATA = data;
  *PORT_DATA = (*PORT_DATA &0xF0) |((data >> 4) & 0x0F);
  RS_HIGH;
  EN_pulse();
  delayMicroseconds(2);
  *PORT_DATA = (*PORT_DATA & 0xF0 ) |(data & 0x0F);
  RS_HIGH;
  EN_pulse();
  delayMicroseconds(2);
}

void EN_pulse(void){
  EN_HIGH;
  delayMicroseconds(2);
  EN_LOW;
  delayMicroseconds(2);
  //delayMicroseconds(100); // Additional delay for 4-bit mode
}
void lcd_control_write(){
  RS_LOW;
  EN_HIGH;
  delay1(1);
  EN_LOW;
  delay1(1);
}

void init_lcd(){
  delay(20);
  outcommand(0x02);//30
  outcommand(0x28);  //8bit -2 line mode
  outcommand(0x28);  //Display on-off control
  outcommand(0x0C);  //Display on-off control
  outcommand(0x06);  //Entry Mode Set
  outcommand(0x01);  //Clear Display
  
}
// void write_command(char command){
//   lcd_control_write();
//   outdata(command);  //Entry Mode Set
//   lcd_control_write();
// }
void write_string(char *ptr){
  while(*ptr != '\0')
  {
    write_data(*ptr);
    ptr++;
  }
}
void write_data(char wr_data){
  outdata(wr_data);
}
void setup() {
  delay(15);
  char *arr = "USE LSB PINS";
  // put your setup code here, to run once:
  init_port();
  init_lcd();

  outcommand(0x80);
  write_string(arr);

}

void loop() {
  // put your main code here, to run repeatedly:
  //right_shift();
 // left_shift();
 //right_Shift_Display();
 
 // delay(1000);
}