#include <avr/io.h>
#include <stdlib.h>
#include <stdio.h>
#include "lcd_io.h"
#include "util/delay.h"

#define DHT11_PIN 6
uint8_t c=0,I_RH,D_RH,I_Temp,D_Temp,CheckSum;

void Request()					/* Microcontroller send start pulse or request */
{
	DDRD |= (1<<DHT11_PIN);
	PORTD &= ~(1<<DHT11_PIN);	/* set to low pin */
	_delay_ms(20);				/* wait for 20ms */
	PORTD |= (1<<DHT11_PIN);	/* set to high pin */
}

void Response()					/* receive response from DHT11 */
{
	DDRD &= ~(1<<DHT11_PIN);
	while(PIND & (1<<DHT11_PIN));
	while((PIND & (1<<DHT11_PIN))==0);
	while(PIND & (1<<DHT11_PIN));
}

uint8_t Receive_data()			/* receive data */
{	
	int q;
	for ( q=0; q<8; q++)
	{
		while((PIND & (1<<DHT11_PIN)) == 0);	/* check received bit 0 or 1 */
		_delay_us(30);
		if(PIND & (1<<DHT11_PIN))	 /* if high pulse is greater than 30ms */
		c = (c<<1)|(0x01);		     /* then its logic HIGH */
		else				         /* otherwise its logic LOW */
		c = (c<<1);
		while(PIND & (1<<DHT11_PIN));
	}
	return c;
}

int main(void)
{	
	char data[5];
	
    lcd_init();					/* initialize LCD */
	lcd_clrscr();			/* clear LCD */
	lcd_gotoxy(0,0);			/* enter column and row position */
	lcd_puts("Humidity:");
	//lcd_gotoxy(1,0);
	//lcd_puts("Temp = ");
	
    while(1)
	{	
		Request();		                       /* send start pulse */
		Response();			                   /* receive response */
		I_RH=Receive_data();	               /* store first eight bit in I_RH */
		D_RH=Receive_data();	               /* store next eight bit in D_RH */
		I_Temp=Receive_data();                 /* store next eight bit in I_Temp */
		D_Temp=Receive_data();	               /* store next eight bit in D_Temp */
		CheckSum=Receive_data();               /* store next eight bit in CheckSum */
		
		if ((I_RH + D_RH + I_Temp + D_Temp) != CheckSum)
		{
			lcd_gotoxy(0,0);
			lcd_puts("Error");
		}
		
		else
		{	
			itoa(I_RH,data,10);
			lcd_gotoxy(11,0);
			lcd_puts(data);
			lcd_puts(".");
			
			itoa(D_RH,data,10);
			lcd_puts(data);
			//lcd_puts("\%");

			//itoa(I_Temp,data,10);
			//lcd_gotoxy(8,1);
			//lcd_puts(data);
			//lcd_putc('.');
			
			//itoa(D_Temp,data,10);
			//lcd_puts(data);
			//lcd_putc(0xDF);
			//lcd_putc('C');
			
			//itoa(CheckSum,data,10);
			//lcd_puts(data);
			//lcd_putc(' ');
		}
				
	_delay_ms(10);
	}	
}