/*
 * ESC_IC_Adrian.c
 *
 * Created: 24.07.2013 18:52:06
 *  Author: Adrian
 
 CPU-Frequency: 8000000Hz
 */ 

#include <avr/io.h>
#include <avr/interrupt.h>

//Globale Variablen

uint8_t start;
uint8_t stop;
uint16_t time;
uint8_t ovflw=0;

int main(void)
{
	
	TCCR1B |= (1<<ICNC1) | (1<<ICES1);			//Noise-Canceler, positive Flanke
	TCCR1B |= (1<<CS11);						//Prescaler 8
	TIMSK |= (1<<TICIE1) | (1<<TOIE1);			//Input-capture interrupt enable, Overflow interrupt enable
	
	DDRC |= (1<<DDRC0);							//PORTC0 als output
	
	sei();										//Interrupts global enable
	

	
    while(1)
	{
		time = ovflw*2^16+stop-start;			//time = stopwert - startwert + (anzahl overflows*2^16)
		
		if(time > 1500)
		{
			PORTC |= (1<<PORTC0);				//Signalleuchte, falls zeit über 1.5 ms
		}
		else
		{
			PORTC &= ~(1<<PORTC0);
		}
	}	
		
}

ISR(TIMER1_CAPT_vect)
{
	if (TCCR1B & (1<<ICES1))
	{
		start = ICR1;						//IC-Register speichern
		TCCR1B &= ~(1<<ICES1);				//Flanke auf negativ
		TIFR = (1<<ICF1);
	} 
	else
	{
		stop = ICR1;						//IC-Register speichern
		TCCR1B |= (1<<ICES1);				//Flanke auf positiv
		TIFR = (1<<ICF1);
		ovflw = 0;							//Anzahl overflows zurücksetzen
	}
}

ISR(TIMER1_OVF_vect)
{
	ovflw += 1;								//Anzahl Overflows erhöhen
}