use constant CHILD_LOG_VERBOSE => 1; # Activate verbose logging

        $l_new_stdout = FileHandle->new(">> /var/log/".$fname."_child_led.log") if CHILD_LOG_VERBOSE;
        $l_new_stdout->autoflush(1) if CHILD_LOG_VERBOSE;

# These values are cycles numbers: moltiply for Timer_resolution to obtain the timer duration
use constant LOG_DURATION_ON => 16;
use constant LOG_DURATION_OFF => 6;
use constant DURATION_ON => 1;
use constant DURATION_OFF => 1; # For quick flashing!

my $Timer_Resolution=250000 ; # 1'000'000 = 1 sec.

my @LED = (
	GREEN_LED,   # Verde
	RED_LED);  # Rosso

# Legal values accepted in FIFO:
my @Commands = (
	"G",      #  - V - Start Green flashing
	"R",      #  - R - Start Red flashing
	"AG",     #  - AV - Alarm green
	"AR" );   #  - AR - Alarm red

my $which=0; # index for array led 
my $alarm_status=0; # Alarm status

my $tmp_command=""; # Value from FFO: it will be immediately cleaned
my $cycles=0; # Cycles Counter

# Boolean Switch of led status (on, off)
# Denying the value 1 I get a "", so I have to work by difference: 1-Switch ...
my $lamp=0; # Stato del led: acceso o spento

my $owserver_led = OWNet->new( "localhost:4304" ) ;

my $appo_dir_list = $owserver_led->dir('/') || die ("Cannot open OWNet connection");
print { $l_new_stdout } (strftime "%b %e %H:%M:%S", localtime). " Initial dir_list to chech owserver connection: $appo_dir_list\n" if LOG_DEBUG;
print { $l_new_stdout } (strftime "%b %e %H:%M:%S", localtime). " Succesfully connected to owserver.\n" if LOG_DEBUG;


# FIFO startup.
# It needs a first input, else it rest blocked here.
# Conseguently I don't need to define a starting value: I'll get it from the FIFO!
  unless (-p $FIFO_TO_CHILD_LED)
  {
    unlink $FIFO_TO_CHILD_LED;
    system('mknod', $FIFO_TO_CHILD_LED, 'p') && die "can't mknod ".$FIFO_TO_CHILD_LED.": $!";
  }

  open (FIFO, "< ".$FIFO_TO_CHILD_LED) || die "can't read ".$FIFO_TO_CHILD_LED.": $!";

# Main !
  while (1) {
	
	if ( $tmp_command ~~ @Commands ) {
		if ( $tmp_command =~ /G/ ) { # G - AG
  			print { $l_new_stdout } (strftime "%b %e %H:%M:%S", localtime). " Child LED: 'G'reen received. \n" if CHILD_LOG_VERBOSE;
			$which=0;
			# Force GREEN on && RED off 
	                $owserver_led->write( BOTH_LED , "0,1" );
		} else { # R - AR
  			print { $l_new_stdout } (strftime "%b %e %H:%M:%S", localtime). " Child LED: 'R'ed received. \n" if CHILD_LOG_VERBOSE;
			$which=1;
			# Force GREEN off && RED on
	                $owserver_led->write( BOTH_LED , "1,0" );
		}
		if ( $tmp_command =~ /A/ ) { # AR - AG
  			print { $l_new_stdout } (strftime "%b %e %H:%M:%S", localtime). " Child LED: 'A'larm received. \n" if CHILD_LOG_VERBOSE;
			$alarm_status=1;
			$cycles=DURATION_ON;
		} else { # R - G 
  			print { $l_new_stdout } (strftime "%b %e %H:%M:%S", localtime). " Child LED: 'A'larm NOT received. \n" if CHILD_LOG_VERBOSE;
			$alarm_status=0;
			$cycles=LOG_DURATION_ON;
		}
		$lamp=1;
		$tmp_command="";
	}

	if ($cycles==0) {
		if ( $lamp ) {
                        print { $l_new_stdout } (strftime "%b %e %H:%M:%S", localtime). " Child LED: IF LAMP! Alarm: $alarm_status - Cycles: $cycles - Lamp: $lamp \n" if CHILD_LOG_VERBOSE;
			if ( $alarm_status ) { $cycles=DURATION_OFF;
			} else {	  $cycles=LOG_DURATION_OFF; }
			$lamp=0;
		} else {
                        print { $l_new_stdout } (strftime "%b %e %H:%M:%S", localtime). " Child LED: ELSE LAMP! Alarm: $alarm_status - Cycles: $cycles - Lamp: $lamp \n" if CHILD_LOG_VERBOSE;
			$cycles=DURATION_ON;
			$lamp=1;
		}
	        $owserver_led->write($LED[$which] , $lamp );
	}
        print { $l_new_stdout } (strftime "%b %e %H:%M:%S", localtime). " Child LED: Alarm: $alarm_status - Cycles: $cycles - Lamp: $lamp \n" if CHILD_LOG_VERBOSE;
	$cycles--;
	
        usleep($Timer_Resolution); 
  }

  close(FIFO);
  unlink $FIFO_TO_CHILD_LED;

	
use sigtrap qw(handler signal_handler normal-signals error-signals old-interface-signals );

# You got mail! Let's go to read it!
use sigtrap 'handler' => \&CambiaLampo, 'USR1';
sub CambiaLampo {
	# If the FIFO contains more than one signal, the good one is the last one...
	# Others are outdated, so clean all and get last!
	while (<FIFO>) {
		$tmp_command = $_;
	}
	chomp $tmp_command;
}