//
//
// hello.ftdi.44.echo.c
//
// 115200 baud FTDI character echo, with flash string
//
// set lfuse to 0x7E for 20 MHz xtal
//
// Neil Gershenfeld
// 12/8/10
//
// (c) Massachusetts Institute of Technology 2010
// Permission granted for experimental and personal use;
// license for commercial sale available from MIT.
//

#include <avr/io.h>
#include <util/delay.h>
#include <avr/pgmspace.h>
#include <stdio.h>

int main(){
	double counter=0;
	double prev=0;
	double interval=5;
	double diff;
	DDRA=_BV(PA7); //128 deximal
	while(1){
		counter++;
		//printf("%ld\n",counter);
	
		//PORTA=_BV(PA7);
		
		PORTA=_BV(PA7);
		_delay_ms(interval/2.0);
		PORTA=0;
		_delay_ms(interval/2.0);
			
			
		if(PINA &  _BV(PA3)){ //high
			PORTA=0;
		}else
		{//low:button on
			
			diff=counter-prev-interval;
			
			if(abs(diff)<0.1*interval){
			interval=interval+5;
			}			
			prev=counter;
			
			//if(abs(counter-prev-interval)<diff){
			//PORTA=_BV(PA7);
			//}
		}		
		
			
		}
	}	
//	_delay_ms(500);