killsaw / printhack

PHP application for turning HP Printers into simple feedback devices

Overview

Many HP printers allow you to set their status LCD to whatever message you'd like. This has historically been used for evil ("ERROR: INTERNAL FIRE" and so on). This tool turns your printer into a useful feedback device, with small amounts of data fed to it at interval by long-running processes.

When you pass by on your way to do something more important, you can take a glance at this glowing blue LCD and know that you're seeing nearly-live data.

Requirements

PHP5.3+ with CLI and socket support compiled in.

Example Usage: Manual message set

$ ./hardset.php -t 192.168.1.79 an example messages

And, poof! Your HP printer should now display the message you've provided.

Example Usage: Running a service

$ ./service.php -t 192.168.1.79 -s Weather

This process will keep active until killed, and update your printer with the current temperature for your area. You can skip the command-line arguments by setting defaults in the config.php file located in the base folder.

Writing a new service

namespace PrintHack;

class SystemLoad implements DataService\DataService
{
	public function getMessage($options=array())
	{
		$uptime = trim(`uptime`);
		$parts = preg_split("/load average[s]?:\s+/i", $uptime, 2);
		return $parts[1];
	}
}

// And to use it...
$console = new Console;
$service = new SystemLoad;
$console->runService($service);

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