Blink(1) CPU monitor for linux. A little perl app which uses vmstat to see how busy the CPU is, and turn the Blink(1) blue through magenta through red, accordingly, using the command-line blink1-tool

cpu.pl

# cpu.pl

# Andy Stanford-Clark
# Feb-13

# seconds between readings from vmstat
$sample_interval = 30;

# drive a blink(1) to represent the CPU usage
# blue is low, red is high

$green=0;

open (PIPE,"vmstat -n $sample_interval |") || die "can't open vmstat pipe";

$lines = 0;
while (<PIPE>)
{
  print;
  chomp;
  $lines++;

  next if $lines < 3;

  @element = split(/ +/,$_);
  $idle = $element[15];
  print "idle: '$idle'\n"; 
  $busy = 100-$idle;

  if ($busy<=50)
  {
    $blue=255;
    $red =int($busy/50*255+0.5);
  }
  else
  {
    $red=255;
    $blue = int((100-$busy)/50*255+0.5);
  }

  print "($red,$green,$blue)\n";
  
  if ($red != $last_red || $blue != $last_blue)
  {
    print "blink(1)\n";
    system("./blink1-tool --rgb $red,$green,$blue");

    $last_red = $red;
    $last_blue = $blue;
  }
}

instructions

run it in the background with something like "screen", or just nohup and & :)
as in (you may have to install screen first)
screen -dmS cpu perl cpu.pl 
or
nohup perl cpu.pl >> /dev/null &

You can change how often it looks at the CPU by changing the $sample_interval in line 7