#include "lcd_definitions.h"

/* Configure the pins of arduino */
void dinit(void){
    //control
    LCD_E_DDR |= (1 << LCD_E_PIN);
    LCD_RS_DDR |= (1 << LCD_RS_PIN);
    //data 
    LCD_D4_DDR |= (1 << LCD_D4_PIN);
    LCD_D5_DDR |= (1 << LCD_D5_PIN);
    LCD_D6_DDR |= (1 << LCD_D6_PIN);
    LCD_D7_DDR |= (1 << LCD_D7_PIN);
}

/* Initialize the LCD as described in the datasheet */
void lcd_init(void){

    _delay_ms(50); //power delay more than 15ms

    LCD_RS_PORT &= ~(1 << LCD_RS_PIN); //RS to low
    LCD_E_PORT &= ~(1 << LCD_E_PIN); //E to low


    // "reboot process"
    lcd_write(LCD_FUNCTION_SET_8bit);
    _delay_ms(10); //more than 4.1ms
    lcd_write(LCD_FUNCTION_SET_8bit);
    _delay_us(200); //more than 100us
    lcd_write(LCD_FUNCTION_SET_8bit);
    _delay_us(200); //more than 100us

    //set to 4bit
    lcd_write(LCD_FUNCTION_SET_4bit);
    _delay_us(80); //more than 39us
    lcd_cmd(LCD_FUNCTION_SET_4bit); 
    _delay_us(80); //more than 39us

    //send instructions
    lcd_cmd(LCD_DISPLAY_OFF);
    _delay_us(80); //more than 39us
    lcd_cmd(LCD_CLEAR);
    _delay_ms(3); //more than 1.53 ms
    lcd_cmd(LCD_ENTRY_MODE);
    _delay_us(80); //more than 39us
    lcd_cmd(LCD_DISPLAY_ON);
    _delay_us(80); //more than 39us

}

/* send an 8bit information to the LCD register in order to be written */
void lcd_write(uint8_t info){
    //(info & 1 << 4) ? LCD_D4_PORT |= (1 << LCD_D4_PIN) :  LCD_D4_PORT &= ~(1 << LCD_D4_PIN)
    if (info & 1<<4){
        LCD_D4_PORT |= (1 << LCD_D4_PIN);
    }
    else {
        LCD_D4_PORT &= ~(1 << LCD_D4_PIN);
    }

    if (info & 1<<5){
        LCD_D5_PORT |= (1 << LCD_D5_PIN);
    }
    else {
        LCD_D5_PORT &= ~(1 << LCD_D5_PIN);
    }

    if (info & 1<<6){
        LCD_D6_PORT |= (1 << LCD_D6_PIN);
    }
    else {
        LCD_D6_PORT &= ~(1 << LCD_D6_PIN);
    }
    if (info & 1<<7){
        LCD_D7_PORT |= (1 << LCD_D7_PIN);
    }
    else {
        LCD_D7_PORT &= ~(1 << LCD_D7_PIN);
    }

    //pulse the Enable pin to indicate we have written the data
    LCD_E_PORT |= (1 << LCD_E_PIN); //high
    _delay_us(1);
    LCD_E_PORT &= ~(1 << LCD_E_PIN); //low
    _delay_us(1);
}

/* send an 8bit instruction to the LCD instruction register */
void lcd_cmd(uint8_t cmd){

    LCD_RS_PORT &= ~(1 << LCD_RS_PIN); //low
    LCD_E_PORT &= ~(1 << LCD_E_PIN); //low
    lcd_write(cmd); // upper 4 bits
    lcd_write(cmd << 4); // lower 4 bits
}

/* send an 8bit data character to the LCD register */
void lcd_char(uint8_t char_data){

    LCD_RS_PORT |= (1 << LCD_RS_PIN); //high
    LCD_E_PORT &= ~(1 << LCD_E_PIN); //low
    lcd_write(char_data); // upper 4 bits
    lcd_write(char_data << 4); // lower 4 bits
}

/* give a string to display to the LCD */
void lcd_string(uint8_t lstring[]){

    //uint8_t lstring = atoi(message);
    volatile int i = 0;
    for (i = 0; lstring[i] != 0 ; i++) {
        lcd_char(lstring[i]);
        _delay_us(80); //more than 39us
    }
}

uint8_t msg[] = "Arduino";
uint8_t msg2[] = "Hello world";

int main(void) {
    dinit();
    lcd_init();
    lcd_string(msg);
    lcd_cmd(LCD_CURSOR_SET | LCD_START_LINE2);
    _delay_us(80); // more than 39us
    lcd_string(msg2);

    while(1);
    return 0;
}