PiloinControl:

To do that, you're going to want to find a way to not sit and wait for an input command. In other words, you want non-blocking input.

It looks like you're headed in the right direction, since your code looks like you're trying to read a character. But by default, perl will wait until you have an entire line of data before it will return from my $char = <STDIN>;. If you use Term::ReadKey, it can let you read a character or get an undef if there isn't a character ready.

I don't have a serial thingie set up on my computer, so here's a silly little example of how you might be able to do it:

$ cat funky_i_o.pl
use strict;
use warnings;
use Term::ReadKey;
use Time::HiRes qw( alarm );

# Buffer used to build our command line
my $command_line = "";

# Buffer for our (fake) serial data
my @serial_data = ();

# Put console into raw mode
ReadMode 4;

setup_serial_interface();

my $are_we_done_yet = 0;
while (!$are_we_done_yet) {

    my $con_key = ReadKey(-1);
    if (defined $con_key) {
        if ($con_key eq "\r" or $con_key eq "\n") {
            # user finished entering the command
            handle_command($command_line);
            $command_line = "";
        }
        else {
            # Not end of line, so add to command line.
            # NOTE: you'll want to handle backspace and/or
            # other line editing commands.  But that's too
            # much work for a quick demo...
            $command_line .= $con_key;
        }
    }
    elsif (is_serial_data_ready()) {
        # Serial device gave us something to do
        handle_serial_data();
    }
    else {
        # Don't eat *ALL* the cpu, since nothing came in from
        # the console or serial line, pause a brief time to let
        # something arrive

        # Here, you'd normally use a sleep or usleep.  But alarm
        # and sleep aren't necessarily on friendly terms with each
        # other, and we're using alarm to fake a serial device. So
        # we're not actually going to delay here, but you would want
        # to in a real application.
    }
}

# Restore normal console mode
ReadMode(0);

sub handle_command {
    my $cmd = shift;
    if ($cmd =~ /^q/i) {
        print "Quitting!\n";
        $are_we_done_yet = 1;
    }
    elsif ($cmd =~ /^d.*(\d+)/i) {
        print "Starting a task that takes $1 seconds!\n";
        my $t = time;
        while ($t + $1 > time) {
            ; # fake process ... just wait until time expires
        }
        print "...and now we're done!\n";
    }
    else {
        print "Unknown command: $cmd\n";
    }
}

###
# Our fake serial interface
###

sub setup_serial_interface {
    my $seconds_per_transmission = 0.567;

    $SIG{ALRM} = sub {
        push @serial_data, rand;
        alarm $seconds_per_transmission;
    };

    # First packet of data should occur in a couple seconds
    alarm 2.5;
}

sub is_serial_data_ready {
    return scalar @serial_data;
}

sub handle_serial_data {
    print "We haz teh dataz! (", join(", ", @serial_data), ")\n";
    @serial_data = ();
}

[download]

When I ran it, I got the following (with a bunch of lines snipped out, as indicated):

$ perl funky_i_o.pl
We haz teh dataz! (0.947528113451884)

   <<< snip!  don't want output to be too long!  >>>

We haz teh dataz! (0.345542351805733)
We haz teh dataz! (0.91829197130572)
Unknown command: now is
We haz teh dataz! (0.226257566965014)
We haz teh dataz! (0.517020773183582)

    <<< snip again! >>>

We haz teh dataz! (0.917061227597888)
Starting a task that takes 5 seconds!
...and now we're done!
We haz teh dataz! (0.214499409451559, 0.574298714543268, 0.86510970635
+5287, 0.412658576047463, 0.56280680260377, 0.488052299033619, 0.60365
+2722987906)
We haz teh dataz! (0.375474185862402)
We haz teh dataz! (0.382325609198627)
Unknown command: now is
We haz teh dataz! (0.951879935396668)

    <<< snip! >>>

We haz teh dataz! (0.760059503593943)
Quitting!

[download]

...roboticus

When your only tool is a hammer, all problems look like your thumb.

In reply to Re: Win32 Serial Read input from device by roboticus
in thread Win32 Serial Read input from device by PilotinControl

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.