Timing Graph

Sometimes it really helps to see data graphically instead of just a bunch of hex and 1's and 0's, so my friend pr0le threw together this perl script that creates an image with a time diagram of the lines. By analyzing this it made it easier to see how they were performing reads and writes to the card.

#!/usr/bin/perl
use GD;

my $logfile = shift || die "usage: $0 <logfile>\n";

open( F, "<$logfile" );
my @lines = <F>;
close( F );

my $len = 3;

my $im_len = scalar( @lines );
my $w = $im_len * $len;
my $h = 100;

my $im = new GD::Image( $w, $h );
my $white = $im->colorAllocate( 255, 255, 255 );
my $black = $im->colorAllocate(   0,   0,   0 );

$im->fill( 0, 0, $white );

my $i   = 1;
my $init = 0;
my ($bit1,$bit2,$rst,$clk);
my ($lbit1,$lbit2,$lrst,$lclk) = (undef,undef,undef,undef);
my ($x1, $y1, $x2, $y2);
foreach my $line ( @lines ) {
   ($bit1,$bit2,$rst,$clk) = ($line =~ m/^(\d)(\d)(\d)(\d)/);
   if( $init ) {
      &print_bit( $lbit1, $bit1, 10 );
      &print_bit( $lbit2, $bit2, 30 );
      &print_bit( $lrst,  $rst, 50 );
      &print_bit( $lclk,  $clk, 70 );
   }
   ($lbit1,$lbit2,$lrst,$lclk) = ($bit1,$bit2,$rst,$clk);
   $init = 1;
   $i++;
}

open( F, ">$logfile.jpg" );
binmode F;
print F $im->jpeg;
close( F );

exit;

sub print_bit {
   my ($old, $new, $ybase) = @_;

   if( $new != $old ) {
      if( $new ) {
         $im->line( $i*$len, $ybase+10, $i*$len, $ybase+20, $black );
         $im->line( $i*$len, $ybase+20, $i*$len+$len, $ybase+20, $black );
      } else {
         $im->line( $i*$len, $ybase+20, $i*$len, $ybase+10, $black );
         $im->line( $i*$len, $ybase+10, $i*$len+$len, $ybase+10, $black );
      }
   } else {
      if( $new ) {
         $im->line( $i*$len, $ybase+20, $i*$len+$len, $ybase+20, $black );
      } else {
         $im->line( $i*$len, $ybase+10, $i*$len+$len, $ybase+10, $black );
      }
   }

   return;
}