Printers are notorious for high operating costs. Usually those come in the form of expensive ink cartridges, which require replacement even when they still contain some ink. But some printers, including Canon Pixma G models, take this a step further with a maintenance cartridge. A new MC-G02 maintenance cartridge only costs around $10, but that adds up if you need to replace yours often. To eliminate that cost, Yancey Wang developed a hack that only requires an Arduino Uno and some wire.

Canon printers use the MC-G02 maintenance cartridge to store waste ink after some operations, such as print head cleaning. The cartridge will soon fill up and Canon expects you to purchase a new cartridge. If you don’t, the printer will stop working. But users can empty and reuse the maintenance cartridge, making a new cartridge unnecessary. The problem is that the cartridge has a built-in “counter” chip, which will tell the printer that the cartridge is full — even if the user emptied it.

This hack works by resetting the chip’s counter, which tricks the printer into believing that the MC-G02 maintenance cartridge is new and ready for use. It does that by rewriting the chip with an “empty” ROM, which the firmware on the maintenance cartridge when it is new. You can get that ROM by either dumping a new chip or finding one online (though it is copyrighted). Yang’s Arduino sketch provides functions for dumping the ROM and uploading a new ROM. You can use both functions through the Serial monitor.  All you need to do is connect four wires to the chip and run them to the Arduino through a pair of resistors.

With this hack, you’ll be able to clean out your maintenance cartridges and reuse them as many times as you like.