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Re^6: r/w attached infrared head on /dev/ttyUSB0

by stoerti (Novice)
on May 30, 2019 at 09:22 UTC ( #11100713=note: print w/replies, xml ) Need Help??


in reply to Re^5: r/w attached infrared head on /dev/ttyUSB0
in thread r/w attached infrared head on /dev/ttyUSB0

Thanks for your help but that doesn't work too.
The problem is not the control sequence, the problem is, that the data is not coming back completely, only the first line comes back.
But why does it work, when I send the sequences from shell and getting it with cat?

  • Comment on Re^6: r/w attached infrared head on /dev/ttyUSB0

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Re^7: r/w attached infrared head on /dev/ttyUSB0
by huck (Parson) on May 30, 2019 at 14:49 UTC

    The problem is not the control sequence

    The hints at the link i provided seem to suggest it is in how you are sending the control sequences, that the timeing is very important.

    Try this

    use Fcntl qw/:DEFAULT/; use IO::Termios (); use IO::Stty (); use IO::Handle; # use IO::Socket; use IO::Select; sysopen my $fh, '/dev/ttyUSB0', O_RDWR or die "sysopen: $!"; my $handle = IO::Termios->new($fh) or die "IO::Termios->new: $!"; $handle->set_mode('300,7,e,1'); IO::Stty::stty($handle, qw/ raw -parodd cs7 -cstopb parenb -ixoff -crt +scts -hupcl -ixon -opost -onlcr -isig -icanon -iexten -echo -echoe -e +choctl -echoke/); my $msg1 = "\x2F\x3F\x21\x0D\x0A"; my $msg2 = "\x06\x30\x30\x30\x0D\x0A"; for my $sleep (qw /.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 1.1 1.2/) { tryit ($msg1,$msg2,$sleep,2); } exit; sub sw{ my $raw=shift; $handle->syswrite($raw) == length($raw) or die "syswrite : $raw"; } sub tryit { my $msg1=shift; my $msg2=shift; my $sleep=shift; my $timeout=shift; my $sel_read = IO::Select->new(); $sel_read-> add($handle); my $didsomething=1; my $buf; print "waiting $sleep between sends\n"; sw($msg1); select (undef,undef,undef,$sleep); sw($msg2); while ($didsomething) { $didsomething=0; my ($rd_ptr,$wr_ptr,$er_ptr)=IO::Select->select($sel_read,undef,un +def,$timeout); for my $fh (@$rd_ptr) { $buf=''; $didsomething=1; my $rv = sysread($fh, $buf, 64*1024, length($buf)); if (!$rv) { if (defined($rv)) { die 'EOF';} else {die 'Connection terminated';} } # bad rv else { print $buf;} } # $fh } # while print "no chars for $timeout secs\n"; } # tryit #for (1..300) { # my $toread = 1; # $handle->sysread(my $in, $toread) # == $toread or die "sysread"; # print $in; #} $handle->close;

    commented out last for loop

Re^7: r/w attached infrared head on /dev/ttyUSB0
by haukex (Chancellor) on May 30, 2019 at 09:32 UTC
    But why does it work, when I send the sequences from shell and getting it with cat?

    One more guess: the two echo commands in the root node may mean the port is opened and closed twice, I think... you might try replicating that in your Perl code.

    (huck's guess was a good one, too bad it didn't work...)

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