#include <avr\io.h> // Most basic include files
#include <avr\interrupt.h> // Add the necessary ones
#include <avr\signal.h>
#include <util\delay.h>
void main(void)
{
unsigned int keystate;
int key_sm(int);
PORTB=0x0f;
TCCR0=0x15;
keystate=1;
while(1)
{
keystate=key_sm(keystate);
}
}
int key_sm(int keystate)
{
int keypress(void);
char buffer;
char getkey(void);
switch(keystate)
{
case 1:
keypress();
if(keypress()== 1)
{
keystate=2;
TCNT0=216;
while(TCNT0<0xFF);
return(keystate);
}
break;
case 2:
if(TIFR==1)
{
keystate=3;
buffer=getkey();
PORTD=buffer;
return(keystate);
}
break;
case 3:
if(keypress()== 1)
{
keystate=2;
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