#define F_CPU 16000000UL
#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>
#include <stdlib.h>

#define lcd_DPRT PORTD //LCD DATA PORT
#define lcd_DDDR DDRD //LCD DATA DDR
#define lcd_DPIN PIND //LCD DATA PIN

#define lcd_CPRT PORTB //LCD COMMANDS PORT
#define lcd_CDDR DDRB //LCD COMMANDS DDR
#define lcd_CPIN PINB //LCD COMMANDS PIN
#define lcd_RS 4 //LCD RS
#define lcd_EN 5 //LCD EN

#define lcd_POT 1 //LCD Potentiometer
#define pot_DDRD DDRC //LCD DATA DDR

float x = 0;
char Vol[] = ("  Voltage:");
char dot[] = (".");


void lcdCommand( unsigned char cmnd ) {
  lcd_DPRT = cmnd & 0xF0; //send high nibble to D4-D7
  lcd_CPRT &= ~ (1 << lcd_RS); //RS = 0 for command
  lcd_CPRT |= (1 << lcd_EN); //EN = 1 for H-to-L pulse
  _delay_us(1); //make EN pulse wider
  lcd_CPRT &= ~ (1 << lcd_EN); //EN = 0 for H-to-L pulse
  _delay_us(100); //wait
  lcd_DPRT = cmnd << 4; //send low nibble to D4-D7
  lcd_CPRT |= (1 << lcd_EN); //EN = 1 for H-to-L pulse
  _delay_us(1); //make EN pulse wider
  lcd_CPRT &= ~ (1 << lcd_EN); //EN = 0 for H-to-L pulse
  _delay_us(100); //wait
}

void lcdData( unsigned char data ) {
  lcd_DPRT = data & 0xF0; //send high nibble to D4-D7
  lcd_CPRT |= (1 << lcd_RS); //RS = 1 for data
  lcd_CPRT |= (1 << lcd_EN); //EN = 1 for H-to-L pulse
  _delay_us(1); //make EN pulse wider
  lcd_CPRT &= ~ (1 << lcd_EN); //EN = 0 for H-to-L pulse
  lcd_DPRT = data << 4; //send low nibble to D4-D7
  lcd_CPRT |= (1 << lcd_EN); //EN = 1 for H-to-L pulse
  _delay_us(1); //make EN pulse wider
  lcd_CPRT &= ~ (1 << lcd_EN); //EN = 0 for H-to-L pulse
  _delay_us(100); //wait
}

void lcd_init() {
  lcd_DDDR = 0xFF;
  lcd_CDDR = 0xFF;
  lcd_CPRT &= ~(1 << lcd_EN); //lcd_EN = 0
  lcdCommand(0x33); //send $33 for init.
  lcdCommand(0x32); //send $32 for init.
  lcdCommand(0x28); //init. LCD 2 line,5×7 matrix
  lcdCommand(0x0e); //display on, cursor on
  lcdCommand(0x01); //clear LCD
  _delay_us(2000);
  lcdCommand(0x06); //shift cursor right
}

void lcd_gotoxy(unsigned char x, unsigned char y) {
  unsigned char firstCharAdr[] = {0x80, 0xC0, 0x94, 0xD4};
  lcdCommand(firstCharAdr[y - 1] + x - 1);
  _delay_us(100);
}

void lcd_print(char * str ) {
  unsigned char i = 0;
  while (str[i] != 0)
  {
    lcdData(str[i]);
    i++ ;
  }
}
int main(void)
{
  lcd_init();
  float Number;
  pot_DDRD |= (1 << lcd_POT); //Potentiometer in
  ADCSRA = 0x8F;           //enable and interrupt select ck/128
  ADMUX = 0x44;            //5V Vref - input right-justified data
  ADCSRA |= (1 << ADSC);   //start conversion once

  while (1) { //stay here forever

    ADCSRA |= (1 << ADSC);          //start conversion once
    while ((ADCSRA & (1 << ADIF)) == 0); //wait for conversion to finish
    Number = ADC;
    lcd_gotoxy(1, 1);
    lcd_print(Vol);

    x = Number / 1024;
    x = x * 5;

    char voltage_str[] = "";
    //Enteros
    lcd_gotoxy(1, 2);
    sprintf(voltage_str, "%d", (int)x);
    lcd_print(voltage_str);

    //Decimales
    lcd_print(dot);
    sprintf(voltage_str, "%d", ((int)(x * 100) % 100) );


    lcd_print(voltage_str);
    lcd_gotoxy(5, 2);
    _delay_ms(100);
  }
  return 0;
}