/*
 * DHT22.c
 *
 * Created: 5/10/2016 5:15:19 am
 *  Author: Dimitrios Porlidas
 */ 
 
#include "LCD_keyb_ROT.h"

uint16_t hum;												// Humidity register
uint16_t tem;												// Temperature register
uint8_t cdig;												// Control digit register
uint8_t i4;
uint8_t i5;
char hum_reg[6];											// Humidity display register
char tem_reg[6];											// Temperature display register
uint8_t err[] = {'E','R','R','O','R',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '};	

void timer1_init()											// Initialize interrupts
{
	TCCR1B |= (1 << WGM12); 								// Configure timer 1 for CTC mode
	TCCR1B |= (5 << CS10); 									// Start timer at Fcpu/1024 (1:/1, 2:/8, 3:/64, 4:/256, 5:/1024)
	TIMSK |= (1 << OCIE1A);									// Enable CTC interrupt
	OCR1A = 15624; 											// Set CTC compare value to 2 seconds at 8MHz AVR clock, with a prescaler of 1024
	sei();													// Enable global interrupts
}



ISR(TIMER1_COMPA_vect)										// Send "Error" message to display if DHT22 does not respond after 2 seconds
{
	SeCu (L2R1);
	_delay_ms(5);
	for (uint8_t i3 = 0; i3 < 16; i3++)
	WrDa(err[i3]);											
}

void GetDHT(void)
{
	timer1_init();
	_delay_ms(1000);
	while (rot1bin == 4)
	{
		_delay_ms (500);
		
		sensddr |= (1<<0);										// Init DHT Port as input
		sensport = 1<<sensbit;									// Rrepear to start communication with DHT
		_delay_ms(10);
		sensport = 0<<sensbit;									// Start communication with DHT, MCU Request (PORTC = 0;)
		_delay_ms(2);
		sensport = 1<<sensbit;									// MCU Request (PORTC = 1;)
		_delay_us(40);
		sensport = 0<<sensbit;									// End of MCU Request
		sensddr &= ~(1<<0);										// Port turns to input (DDRC = 0;)
		sensport = 1<<sensbit;									// Enable pull up (PORTC = 1;)
		_delay_us(20);
		while (!(bit_is_set(sensreg,0)));						// DHT Response 0, wait for 1
		_delay_us(100);
		
		hum = 0;
		for (uint8_t i1 = 0; i1 < 16; i1++)						// Start reading humidity 16-bit register
		{
			while (!(bit_is_set(sensreg,0)));					// Wait for 1
			_delay_us(40);
			hum = (hum<<1);
			if (bit_is_set(sensreg,0))							// Read 1
			{
				hum |= (1<<0);
//				while (bit_is_set(sensreg,0));					// Wait for 0
				i5=0;
				while (bit_is_set(sensreg,0))
				{
					i5++;
					_delay_us(5);
					if (i5 > 100)
					{
						SeCu (L2R1);
						_delay_ms(5);
						for (uint8_t i3 = 0; i3 < 16; i3++)
						WrDa(err[i3]);
						break;
					}
				}
			}
//			else												// Read 0 (no need for this routine because bit is 0 due to shift function)
//			hum &= ~(1<<0);
		}
		
		tem = 0;
		for (uint8_t i1 = 0; i1 < 16; i1++)						// Start reading temperature 16-bit register
		{
			while (!(bit_is_set(sensreg,0)));					// Wait for 1	
			_delay_us(40);
			tem = (tem<<1);
			if (bit_is_set(sensreg,0))							// Read 1
			{
				tem |= (1<<0);
//				while (bit_is_set(sensreg,0));					// Wait for 0
				i5=0;
				while (bit_is_set(sensreg,0))
				{
					i5++;
					_delay_us(5);
					if (i5 > 100)
					{
						SeCu (L2R1);
						_delay_ms(5);
						for (uint8_t i3 = 0; i3 < 16; i3++)
						WrDa(err[i3]);
						break;
					}
				}
			}
//			else												// Read 0 (no need for this routine because bit is 0 due to shift function)
//			tem &= ~(1<<0);
		}
		
		for (uint8_t i1 = 0; i1 < 8; i1++)						// Start reading control digit 8-bit register
		{
			while (!(bit_is_set(sensreg,0)));					// wait for 1
			_delay_us(40);
			cdig = (cdig<<1);
			if (bit_is_set(sensreg,0))							// Read 1
			{
				cdig |= (1<<0);
//				while (bit_is_set(sensreg,0));					// Wait for 0
				i5=0;
				while (bit_is_set(sensreg,0))
				{
					i5++;
					_delay_us(5);
					if (i5 > 100)
					{
						SeCu (L2R1);
						_delay_ms(5);
						for (uint8_t i3 = 0; i3 < 16; i3++)
						WrDa(err[i3]);
						break;
					}
				}
			}
//			else
//			cdig &= ~(1<<0);								// Read 0 (no need for this routine because bit is 0 due to shift function)
		}
				
		SeCu (L2R1); _delay_ms (5);
		WrDa('H');											
		WrDa('=');
		itoa (hum, hum_reg, 10);							// integer to ASCII function
//		SeCu (L1R3); _delay_ms (5);							// Send cursor to a specific address 0-80 (LCD)		
		for (i4 = 0; i4 < ((unsigned)strlen(hum_reg)-1); i4++)	// Send ASCII string to LCD, but not null characters, except the last digit (decimal)
		WrDa (hum_reg[i4]);
		WrDa('.');											// Send . to LCD for decimal digit
		WrDa (hum_reg[i4]);									// Send the last digit (decimal) to LCD
		WrDa('%');											// Send % symbol
		for (i4 = (unsigned)strlen(hum_reg); i4 < 6; i4++)	// Complete with blanks
		WrDa(' ');
		
		SeCu (L2R9); _delay_ms (5);
		WrDa('T');
		WrDa('=');
		itoa (tem, tem_reg, 10);							// integer to ASCII function
//		SeCu (L2R6); _delay_ms (5);							// Send cursor to a specific address 0-80 (LCD)		
		for (i4 = 0; i4 < ((unsigned)strlen(tem_reg)-1); i4++)	// Send ASCII string to LCD, but not null characters, except the last digit (decimal)
		WrDa (tem_reg[i4]);
		WrDa('.');											// Send . to LCD for decimal digit
		WrDa (tem_reg[i4]);									// Send the last digit (decimal) to LCD
		WrDa(223);											// Send degree symbol
		WrDa('C');											// Write C at the end of number (for Celcius)
		for (i4 = (unsigned)strlen(tem_reg); i4 < 5; i4++)	// Complete with blanks
		WrDa(' ');
		
		TCNT1 = 0;											// Reset TCNT1
	}
}