Schlagwort: Uno

With the rapid pace of solar panel installations over the course of the previous decade, there has been an ongoing challenge of trying to improve their efficiency. Apart from the typical silicon crystal photovoltaic cells, there are also more efficient/expensive cells known as concentration photovoltaics (CPV), which rely on a set of mirrors to focus sunlight into a small multijunction cell. Although this technology reduces the size and material requirements, it also requires precise sun tracking for peak performance.

Ruediger Loechenhoff has been able to create a far cheaper solar tracker controller, which relies on an Arduino Uno to drive a set of two motors that position the panel. To achieve this, the Uno was connected to a 9-axis MPU-9250 compass module for internal positioning, a DS3231 real-time clock for accurate timing, and a DIY shading beam sunlight sensor to detect optimal angles. Operating the tracker is also quite simple since the firmware only requires an occasional calibration step after a set number of days.

In terms of safety and reliability, the CPV tracker uses a combination of firmware checks and hardware stops to ensure everything operates normally. For instance, a motor collision causes its current draw to spike which can be quickly cut off from the current detector circuit. Moving too far in one direction will also pull the primary power connector, therefore removing power from the motors.

More information on the project — which was named a finalist in the Planet-Friendly Power round of this year’s Hackaday Prize — can be found in Loechenhoff’s write-up. 

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.