#!/usr/bin/perl
#

use strict;

use RPi::Pin;
use RPi::Const qw(:all);

my $pin4 = RPi::Pin->new(4);
$pin4->mode(INPUT);
$pin4->set_interrupt(EDGE_RISING, "main::pin4_interrupt_handler");

my $pin19 = RPi::Pin->new(19);
$pin19->mode(OUTPUT);
$pin19->write(LOW);

my $pin4prev = 0;
my $cnt = 0;
while (1) {
   my $num = $pin4->num;
   my $mode = $pin4->mode;
   my $state = $pin4->read;
   if ($state != $pin4prev) {
       print "pin number $num is in mode $mode with state $state\n";
       $pin4prev = $state;
   }

   my $val = ($cnt % 2);
   $num = $pin19->num;
   $mode = $pin19->mode;
   $pin19->write($val);
   sleep(1);
   $cnt++;
}

sub pin4_interrupt_handler {
   print "in pin4 interrupt handler\n";
}