Planet Arduino

While it can be straightforward to distill water to high purity, this is rarely the best method for producing water for useful purposes. Even drinking water typically needs certain minerals in it, plants may need a certain pH, and wastewater systems have a whole host of other qualities that need to be measured. Measuring water quality is a surprisingly complex endeavor as a result and often involves a wide array of sensors, much like this water quality meter from [RowlesGroupResearch].

The water quality meters that they are putting to use are typically set up in remote locations, without power, and are targeting natural bodies of water and also wastewater treatment plants. Temperature and pH are simple enough to measure and grasp, but this device also includes sensors for total dissolved solids (TDS) and turbidity which are both methods for measuring various amounts and types of particles suspended in the water. The build is based around an Arduino so that it is easy for others to replicate, and is housed in a waterproof box with a large battery, and includes data logging to an SD card in order to make it easy to deploy in remote, outdoor settings and to gather the data at a later time.

The build log for this device also goes into detail about all of the steps needed to set this up from scratch, as well as a comprehensive bill of materials. This could be useful in plenty of professional settings such as community wastewater treatment facilities but also in situations where it’s believed that industrial activity may be impacting a natural body of water. For a water quality meter more focused on drinking water, though, we’d recommend this build that is trained on its own neural network.

[Adam Welch] has built macro pads in the past out of pre-fab key matrices and handfuls of Cherry MX clones. But all the stickers and custom keycaps in the world wouldn’t make those macro pads as versatile as a stream deck — those visual shortcut panels with tiny touchscreens for each button that some streamers use to change A/V settings or switch between applications.

Let’s face it, stream decks are expensive. But 0.96″ OLED displays are not, and neither are SMD tactile buttons. Why not imitate a screen deck on the cheap by making it so the screens actuate buttons behind them? [Adam] based this baby on the clever design of [Kilian Gosewisch]’s FreeDeck, and they ended up working together to improve it with a dedicated PCB.

The brains of the operation is an Arduino Pro Micro, which addresses each screen individually via two 74HC4051 mux ICs. Thanks to an SD card module, there’s no need to flash the ‘duino every time you want to change a shortcut or its picture. Even if this deck doesn’t hold up forever, it won’t break the bank to build another one. Poke past the break for the build video, which has all the links you’d need to make your own, including a handy configurator.

There’s more than one way to do a visual macro pad. Here’s one that uses a single screen and splits it Brady Bunch style to match the matrix.

Thanks for the tip, [arturo182]!

[Amirreza Nasiri] sends in this cool USB keystroke injector.

The device consists of an Arduino, a Bluetooth module, and an SD card. When it’s plugged into the target computer the device loads the selected payload from the SD card, compromising the system. Then it does its unique trick which is to switch the injector over to Bluetooth mode. Now the attacker has much more control, albeit local, over the system.

While we would never even be tempted to plug this device into a real computer, we like some of the additional features, like how an added dip switch can be used to select from up to eight different payloads depending on the required attack. The addition of a photo diode is also interesting, and makes us dream of all sorts of impractical movie hacker scenarios. [Amirreza] says it’s to trigger when the person leaves the room and turns the lights off.

[Amirreza] has all the code and design files on the GitHub. There are also a few payload examples, which should be fun to hack on. After all, one of life’s pleasures is to find new ways to mess with your friends.

by jazzycamel:

I work as a software developer for a biology lab where my day job consists of creating applications to deal with big data visualisation. Recently however one of my colleagues had the need to take regular temperature measurements form a range of jars of liquids over quite an extended period. The commercial available solutions to achieve this are expensive and surprisingly lacking in features. So, as a dedicated hacker and maker, I immediately stepped in an said we could make something better ourselves. So we did. And this is how.

Quick & Easy Temperature Loggers - [Link]

A few days ago, one of [Severin]‘s SD cards died on him, Instead of trashing the card, he decided to investigate what was actually wrong with the card and ended up recovering most of the data using an Arduino and an immense amount of cleverness.

SD cards can be accessed with two modes. The first is the SDIO mode, which is what cameras, laptops, and other card readers use. The second mode is SPI mode. SPI is slower, but much, much simpler. It turned out the SDIO mode on [Severin]‘s card was broken, but accessing it with an Arduino and SPI mode worked. There was finally hope to get files off this damaged card.

[Severin] used a few sketches to dump the data on the SD card to his computer. The first looked at the file system and grabbed a list of files contained on the card. The second iterated over the file system and output all the files in hex over the serial port. With a bit of Python, [Severin] was able to reconstruct a few files that were previously lost forever.

Even though the SD card was completely inaccessible with a normal card reader, [Severin] was able to get a few files off the card. All the sketches and Python scripts are available on the Githubs, ready to recover files from your broken SD cards.