send HPGL to plotter over GPIB

plot-hpgl-gpib.pl

#!/usr/bin/env perl
# Send HPGL to plotter
#
# Unrelated curious marc video on pen adapter https://youtu.be/h-oj4HrTH14?t=471

use strict;
use warnings;

use LinuxGpib;
use Getopt::Std;
use File::Temp qw/ tempfile tempdir /;
use Time::HiRes qw(usleep time gettimeofday);

my $device;
my $inputFile;

#----------
# usage and option initialization
my $opt_string = 'hd:';
sub usage() {
print STDERR << "EOF";

usage: $0 -h|-d PRIMARY_ADDRESS INPUTFILE

This program sends HPGL to a plotter.
EOF
}

#----------------------
getopts( "$opt_string", \my %opt ) or usage() and exit;

my $arglen = scalar @ARGV;
if($arglen == 0 or $opt{h} or not $opt{d}) {
    usage();
    exit;
}

if ($opt{d}) {
    $device = $opt{d};
}

$inputFile = $ARGV[0];
print "device is $device\ninputFile is $inputFile\n";

open my $inputFH, '<', $inputFile || die "cannot open input inputFile $inputFile";

my $minor    = 0;        # gpib driver major
my $pad      = $device;  # device primary bus address
my $sad      = 0;        # device secondary bus address
my $send_eoi = 1;        # Assert eoi with last byte in ibwrt
my $eos_mode = 0;        # No end of string processing
my $timeout  = 17;       # 1000 seconds https://linux-gpib.sourceforge.io/doc_html/reference-function-ibtmo.html


# ibsta return codes from the gpib library.
# https://linux-gpib.sourceforge.io/doc_html/reference-globals-ibsta.html
my $CMPL= 0x200;
my $END = 0x2000;
my $TIMO= 0x4000;
my $ERR = 0x8000;

printf("Attempting to open /dev/gpib%i\n"
    . "pad = %d, sad = %d, timeout = %d, send_eoi = %d, eos_mode = 0x%04x\n",
    $minor, $pad, $sad, $timeout, $send_eoi, $eos_mode);
# connect with 300ms timeout instead of $timeout so we can ensure IN completes in 300ms so we know we have a working device
my $dev = LinuxGpib::ibdev($minor, $pad, $sad, 10, $send_eoi, $eos_mode);

sub checkError {
    my $ret = $_[0];
    if($ret & $ERR) {
        printf("ret err: 0x%04X\n", $ret);
        printf("iberr: %02X\n", LinuxGpib::ThreadIberr());
        die "dunno what to do about errors\n";
    }
}

my $ret;
my $deviceData;
my $ready;

# try to initialize
$ret = LinuxGpib::ibwrt($dev, 'IN;', length('IN;'));
checkError($ret);

#if it didn't time out, we have a device so increase the timeout so commands don't get lost
$ret = LinuxGpib::ibtmo($dev, $timeout);
checkError($ret);

while (my $command = <$inputFH>) {
    chomp $command;
    print "$command\n";
    $ret = LinuxGpib::ibwrt($dev, $command, length($command));
    checkError($ret);
    usleep(10000);

    # the manual says that you should read the plotter's output buffer to clear
    # it, but leaving this out doesn't seem to cause problems here.

    #$ret = LinuxGpib::ibrd($dev, $deviceData, 2004);
    #usleep(10000);

    $ret = LinuxGpib::ibwrt($dev, 'OA;', length('OA;'));
    checkError($ret);
    usleep(10000);

    $ret = LinuxGpib::ibrd($dev, $deviceData, 2004);
    $deviceData =~ s/\s+//g;        #remove whitespace
    print "read from plotter '$deviceData'\n";
    checkError($ret);
    usleep(10000);
}