#define F_CPU 16000000UL
#include <avr/io.h>
#include <util/delay.h>
#include <string.h>
#include <math.h>
#include <stdio.h>

#define LCD_Port PORTD			//Definir LCD Port (PORTC, PORTD) como entrada
#define LCD_DPin  DDRD			//Definir Pins (PD4-PD7) como salida
#define RSPIN PD2			      
#define ENPIN PD3			     

void LCD_Action( unsigned char cmnd );
void LCD_Init (void);
void LCD_Clear();
void LCD_Print (const char *str);
void LCD_Printpos (char row, char pos, char *str);
float x = 0;
unsigned char xchar; 
void LCD_Init (void)
{
	LCD_DPin = 0xFF;		//Controlar Pins (D4-D7)
	_delay_ms(15);		
	LCD_Action(0x02);	
	LCD_Action(0x28);       
	LCD_Action(0x0c);       
	LCD_Action(0x06);       
	LCD_Action(0x01);       
	_delay_ms(2);
}

void LCD_Action( unsigned char cmnd )
{
	LCD_Port = (LCD_Port & 0x0F) | (cmnd & 0xF0);
	LCD_Port &= ~ (1<<RSPIN);
	LCD_Port |= (1<<ENPIN);
	_delay_us(1);
	LCD_Port &= ~ (1<<ENPIN);
	_delay_us(200);
	LCD_Port = (LCD_Port & 0x0F) | (cmnd << 4);
	LCD_Port |= (1<<ENPIN);
	_delay_us(1);
	LCD_Port &= ~ (1<<ENPIN);
	_delay_ms(2);
}

void LCD_Clear()
{
	LCD_Action (0x01);	
	_delay_ms(2);			
	LCD_Action (0x80);	
}

void LCD_Print (const char *str)
{
	int i;
	for(i=0; str[i]!=0; i++)
	{
		LCD_Port = (LCD_Port & 0x0F) | (str[i] & 0xF0);
		LCD_Port |= (1<<RSPIN);
		LCD_Port|= (1<<ENPIN);
		_delay_us(1);
		LCD_Port &= ~ (1<<ENPIN);
		_delay_us(200);
		LCD_Port = (LCD_Port & 0x0F) | (str[i] << 4);
		LCD_Port |= (1<<ENPIN);
		_delay_us(1);
		LCD_Port &= ~ (1<<ENPIN);
		_delay_ms(2);
	}
}

void LCD_Printpos (char row, char pos, char *str)
{
	if (row == 0 && pos<16)
	LCD_Action((pos & 0x0F)|0x80);
	else if (row == 1 && pos<16)
	LCD_Action((pos & 0x0F)|0xC0);
	LCD_Print(str);
}

int main()
{
  float n;
	LCD_Clear();
	LCD_Init(); //ActivaR  Pantalla LCD
	LCD_Print("   Voltimetro");	
	DDRC = 0; // puerto 0 entrada del ADC

	ADCSRA= 0x8F; 
	ADMUX= 0x40;
	ADCSRA|=(1<<ADSC); // Inicia la conversion
	
	while (1){
    ADCSRA|=(1<<ADSC); //inicia la conversion
    while((ADCSRA&(1<<ADIF))==0); // espera a que termine la conversion
  
    n = ADC&1023; 
    LCD_Action (0x80);
    LCD_Print("   Voltimetro");
    x =n*0.00488; // 4.49
    char string[]="";
    LCD_Action (0xC0);
    sprintf(string, "%d", (int)x); // 4
    LCD_Print(string);
  
    sprintf(string, ".");
    LCD_Print(string);
    sprintf(string, "%d", ((int)(x*100)%100)); 
    LCD_Print(string);
  }
}

void reverse(char* str, int len)
{
	int i = 0, j = len - 1, temp;
	while (i < j) {
		temp = str[i];
		str[i] = str[j];
		str[j] = temp;
		i++;
		j--;
	}
}

int intToStr(int x, char str[], int d)
{
	int i = 0;
	while (x) {
		str[i++] = (x % 10) + '0';
		x = x / 10;
	}

	while (i < d)
	str[i++] = '0';
	
	reverse(str, i);
	str[i] = '\0';
	return i;
}


void ftoa(float n, char* res, int afterpoint)
{
	int ipart = (int)n;
	float fpart = n - (float)ipart;
	int i = intToStr(ipart, res, 0);
	if (afterpoint != 0) {
		res[i] = '.'; // add dot
		fpart = fpart * pow(10, afterpoint);
		intToStr((int)fpart, res + i + 1, afterpoint);
	}
}