LEGO sets have long been able to work with simple pneumatic controls, but what about a full air compressor built out of these components? Would this be possible?

As demonstrated in the video below, this can in fact be accomplished, and in brilliant style no less. The design uses four motors, eight pneumatic pumps, and 10 air tanks to produce a pressure of 35PSI and beyond.

Controls consist of an Arduino board, along with a pair of resistors to set two separate tank pressures. User feedback is provided by two external displays, and the setup even features a lighting system to allow “workers” to perform maintenance access 24 hours a day!

For a quick start, the compressor has a Turbo function which is enabled under 35 psi this makes the motors run on 12V instead of the rated 9V. This way the air tanks are filled a bit faster but without overloading the motors.

The compressor has two sections which can be used separately with their own setpoint or as one big compressor. This selection is done by switching the outlet valves at the back of the compressor and by setting a jumper on the circuit board.

The Arduino control also tracks the running time of each section in hours and is shown when a switch on the circuit board is pressed.

The pressure is measured by a non official Lego pneumatic sensor by Mindsensors.com.

In case you happen to have an ocean nearby, you’re probably familiar with its rising and falling tides. And if mudflat hiking is a thing in your area, you’re also aware of the importance of good timing and knowing when the water will be on its way back. Tide clocks will help you to be prepared, and they are a fun alternative to your usual clock projects. If you’re looking for a starting point, [rabbitcreek] put together an Arduino-based tide clock kit for educational purposes.

If you feel like you’re experiencing some déjà vu here, this indeed isn’t [rabbitcreek]’s first tide clock project. But unlike his prior stationary clock, he has now created a small and portable, coin-cell version to take with you out on the sea. And what shape would better fit than a 3D printed moon — unfortunately the current design doesn’t offer much waterproofing.

For the underlying tide calculation itself, [rabbitcreek] uses just like in his previous project [Luke Miller]’s location-based library for the ubiquitous DS1307 and DS3213 real-time clocks. Of course, if you also want to keep track of other events on your clock, why not set up calendar events for the next rising tide?

A few months back we first brought word of the progress being made in unlocking the SMART Response XE, an ATmega128RFA powered handheld computer that allowed teachers to create an interactive curriculum in the days before all the kids got Chromebooks. Featuring 2.4 Ghz wireless communication, a 384×160 LCD, and a full QWERTY keyboard, schools paid around $100 each for them 2010. Now selling for as little as $5 on eBay, these Arduino-compatible devices only need a little coaxing and an external programmer to get your own code running.

The previous post inspired [Larry Bank] to try his hand at hacking the SMART Response XE, and so far he’s made some very impressive progress. Not only has he come up with his own support library, but he’s also created a way to upload Arduino code to the devices through their integrated 802.15.4 radio. With his setup, you no longer need to open the SMART Response XE and attach a programmer, making it much easier to test and deploy software.

[Larry] has written up a very detailed account of his development process, and goes through the trouble of including his ideas that didn’t work. Getting reliable communication between two of these classroom gadgets proved a bit tricky, and it took a bit of circling around until he hit on a protocol that worked.

The trick is that you need to use one SMART Response XE attached to your computer as a “hub” to upload code to other XEs. But given how cheap they are this isn’t that big of a deal, especially considering the boost in productivity it will net you. [Larry] added a 5 x 2 female header to his “hub” XE so he could close the device back up, and also added a physical power switch. In the video after the break, you can see a demonstration of the setup sending a simple program to a nearby XE.

Between this wireless bootloader and the Arduboy compatibility covered previously, we’d suggest you get your SMART Response XE now. We wouldn’t be surprised if the prices of these things start going up like they did with the IM-ME.

After finding a broken lamp at a scrapyard, which as meant to throw light both up and down, “tuenhidiy” decided to fix it. However, instead of using the normal two-bulb configuration, he replaced these lights with 64 individual RGB LEDs. The results are beautiful, as seen in the videos below.

Interestingly, this maker didn’t use NeoPixel-style programmable RGB lighting, but rather opted to control each RGB component directly using an Arduino, along with a shift register and transistor assembly. LED soldering was accomplished with the help of a flat wooden jig. The attached LEDs were then rolled up to fit the cylindrical fixture.

Lighting can be controlled in three modes—color wheel, morph, and HSB to RGB—with a potentiometer, selectable via a 3-way switch.

If you need a certain electrical signal for testing, there are a variety of function generators available at a wide range of prices and capabilities. If, however, you’d like to build your own, this project by maker “Faransky” looks like a great place to start.

An Arduino Nano forms the core of this device, which interfaces with an AD9833 waveform generator module to produce the proper wave output. User interface is via a single encoder, which steps through different menu options using a built-in pushbutton, and a two-line LCD display provides feedback.

Everything is housed inside a nice compact enclosure, along with a lithium-ion battery to make it portable. Its capabilities are shown off in the video below, and build instructions and code are available here. 

The CatGenie is an amazing device to watch in action, basically a self-cleaning litter box for cats that even does away with the need to replace the litter. It’s comparable to what the indoor flush toilet is for humans compared to maintaining a composting toilet. However, there is a problem. It uses costly soap cartridges which have to be replaced because an RFID reader and a usage counter prevent you from simply refilling them yourself.

[David Hamp-Gonsalves] reverse engineered the electronics so that he didn’t have to pay for the cartridges anymore. This has been done before and one of those who did it created a product called the CartridgeGenius, but it’s made and sold as a parttime project and there were none in stock. The cartridges have an RFID tag and another solution which we’ve covered before is to replace the RFID reader board with an Arduino. That’s the solution [David] adopted. So why write this post if this isn’t new?

The RFID reader board communicates with the rest of the CatGenie using I2C and he needed to know what was being transmitted. To do that he learned how to use a cheap logic analyzer to read the signals on the I2C wires, which makes this an interesting story. You can see the logic analyser output on his blog and GitHub repository along with mention of a timing issue he ran into. From what he learned, he wrote up Arduino code which sends the same signals. He and his cat are now sitting pretty.

What he didn’t do is make a video. But the CatGenie really is amazing to watch in action as it goes through its rather complex 30-35 minute process so we found a video of it doing its thing, shown at 3.5x speed, and included that below.  If you’re into that sort of thing.

[via Adafruit]

In nature, animals often are sensitive to the outside environment, retreating into a hole, shell, or other protective structure upon sensing sudden movements. If you were to envision this kind of behavior in robot form, you might come up with something like “The Shy Machine” from Daric Gill Studios.

When it detects motion via a PIR sensor, the shell-like robot takes a reading of the ambient sound level using an internal microphone. If things are sufficiently quiet, it opens up using a stepper motor and lead screw, revealing a rainbow of colors provided by an array of RGB LEDs inside.

Its construction and a demo video are shown below, and you can see more about how this Arduino-powered robot was built and the results on Gill’s website.

If you’re a fan of Portal games, you’d probably like nothing more than to have your own Wheatley Personality Core to accompany you on real-life adventures. While that would be a passing thought for most, Luke Albertson has created his own amazing replica of the Portal 2 character. 

The device not only can say over 40 phrases from the game via an Adafruit soundboard, but contains a glowing blue eyeball that can pan, tilt, twist, and blink to help express what it’s thinking. It even has handles that move up and down, adding a kind of “flailing arms” effect to convey its emotions. 

Albertson’s animatronic project is controlled by an Arduino Uno, along with a Bluetooth shield and PS3 controller for user interface. It’s shown off quite nicely in the video below, and more info and clips are available here.