Comments on: Connect to Serial Port Using Perl

By: dmw

dmw — Thu, 17 Nov 2011 21:29:34 +0000

The example above will spin on cpu, reading as fast as the processor can cycle through the loop.

# to effectively poll at .1 second intervals, try setting:
$port->read_char_time(0);
$port->read_const_time(100);

# and in your while loop, don’t have read do so much work, and only print if you have something to print:
while (1) {
my ($count,$bytes) = $port->read(255);
print “$bytes” if $count > 0;
}

By: dmw

dmw — Thu, 17 Nov 2011 21:27:37 +0000

Thanks for the simple example. Couple of notes, though:

The example above will spin on cpu, reading as fast as the processor can cycle through the loop.

# to effectively poll at .1 second intervals, try setting:
$port->read_char_time(0);
$port->read_const_time(100);

# and in your while loop, don’t have read do so much work, and only print if you have something to print:
while (1) {
my ($count,$bytes) = $port->read(255);
print “$bytes” if $count > 0;
}

By: Chris

Chris — Tue, 18 Aug 2009 14:15:04 +0000

Nice! This is the first example that I’ve tried that actually worked! The main difference is that most sites have you use

my $byte = $port->lookfor(); #Which does not work!!!

my $byte = $port->read(1); #works!!!

Thanks!