Standing Desk Uses Pneumatics To Do The Job

Most standing desks on the market use electric motors or hand cranks to raise and lower the deck. However, [Matthias Wandel] found a Kloud standing desk that used an altogether different set up. He set about figuring out how it worked in the old-fashioned way—by pulling it apart.

The Kloud desk relies on pneumatics rather than electrical actuators to move up and down. Inside the desk sits a small tank that can be pressurized with a hand-cranked mechanism. A lever can then be used to release pressure from this tank into a pair of pneumatic cylinders that drive the top of the desk upwards. The two cylinders are kept moving in sync by a tensioned metal ribbon that ties the two sides together. The mechanism is not unlike a gas lift chair—holding the lever and pushing down lets the desk move back down. Once he’s explained the basic mechanism, [Matthias] gets into the good stuff—pulling apart the leg actuator mechanism to show us what’s going on inside in greater detail.

If you’ve ever thought about building your own standing desk, this might be a video worth watching. We’ve featured some other great pneumatics projects before, too. Video after the break.

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Can Digital Poison Corrupt The Algorithm?

These days, so much of what we see online is delivered by social media algorithms. The operations of these algorithms are opaque to us; commentators forever speculate as to whether they just show us what they think we want to see, or whether they try to guide our thinking and habits in a given direction. The Digital Poison device  from [Lucretia], [Auxence] and [Ramon] aims to twist and bend the algorithm to other ends.

The concept is simple enough. The device consists of a Raspberry Pi 5 operating on a Wi-Fi network. The Pi is set up with scripts to endlessly play one or more select YouTube videos on a loop. The videos aren’t to be watched by anyone; the device merely streams them to rack up play counts and send data to YouTube’s recommendation algorithm. The idea is that as the device plays certain videos, it will skew what YouTube recommends to users sharing the same WiFi network based on perceived viewer behavior.

To achieve subtle influence, the device is built inside an unobtrusive container. The idea being that it could be quietly connected to a given WiFi network to stream endlessly, in turn subtly influencing the view habits of other users on the same network.

It’s difficult to say how well this concept would work in practice. In many cases, sites like YouTube have robust user tracking that feeds into recommendation algorithms. Activity from a random user signed into the same network might not have much of an influence. However, conceptually, it’s quite interesting, and the developers have investigated ways to log the devices operation and compare it to recommendations fed to users on the network. Privacy provisions make this difficult, but it may be possible to pursue further research in this area. Files are on Github for the curious.

Ultimately, algorithms will always be a controversial thing as long as the public can’t see how they work or what they do. If you’re working on any projects of your own in this space, don’t hesitate to let us know!

[Thanks to Asher for the tip!]

Audio Localization Gear Built On The Cheap

Most humans with two ears have a pretty good sense of directional hearing. However, you can build equipment to localize audio sources, too. That’s precisely what [Sam], [Ezra], and [Ari] did for their final project for the ECE4760 class at Cornell this past Spring. It’s an audio localizer!

The project is a real-time audio localizer built on a Raspberry Pi Pico. The Pico is hooked up to three MEMS microphones which are continuously sampled at a rate of 50 kHz thanks to the Pico’s nifty DMA features. Data from each microphone is streamed into a rolling buffer, with peaks triggering the software on the Pico to run correlations between channels to determine the time differences between the signal hitting each microphone. Based on this, it’s possible to estimate the location of the sound source relative to the three microphones.

The team goes into great deal on the project’s development, and does a grand job of explaining the mathematics and digital signal processing involved in this feat. Particularly nice is the heatmap output from the device which gives a clear visual indication of how the sound is being localized with the three microphones.

We’ve seen similar work before, too, like this project built to track down fireworks launches. Video after the break.

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Meet Cucumber, The Robot Dog

Robots can look like all sorts of things, but they’re often more fun if you make them look like some kind of charming animal. That’s precisely what [Ananya], [Laurence] and [Shao] did when they built Cucumber the Robot Dog for their final project in the ECE 4760 class.

Cucumber is controllable over WiFi, which was simple enough to implement by virtue of the fact that it’s based around the Raspberry Pi Pico W. With its custom 3D-printed dog-like body, it’s able to move around on its four wheels driven by DC gear motors, and it can flex its limbs thanks to servos in its various joints. It’s able to follow someone with some autonomy thanks to its ultrasonic sensors, while it can also be driven around manually if so desired. To give it more animal qualities, it can also be posed, or commanded to bark, howl, or growl, with commands issued remotely via a web interface.

The level of sophistication is largely on the level of the robot dogs that were so popular in the early 2000s. One suspects it could be pretty decent at playing soccer, too, with the right hands behind the controls. Video after the break.

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Mechanical 7-Segment Display Combines Servos And Lego

If you need a seven-segment display for a project, you could just grab some LED units off the shelf. Or you could build something big and electromechanical out of Lego. That’s precisely what [upir] did, with attractive results.

The build relies on Lego Technic parts, with numbers displayed by pushing small black axles through a large yellow faceplate. This creates a clear and easy to read display thanks to the high contrast. Each segment is made up of seven axles that move as a single unit, driven by a gear rack to extend and retract as needed. By extending and retracting the various segments in turn, it’s possible to display all the usual figures you’d expect of a seven-segment design.

It’s worth noting, though, that not everything in this build is Lego. The motors that drive the segments back and forth are third-party components. They’re Geekservo motors, which basically act as Lego-mountable servos you can drive with the electronics of your choice. They’re paired with an eight-channel servo driver board which controls each segment individually. Ideally, though, we’d see this display paired with a microcontroller for more flexibility. [upir] leaves that as an exercise for the viewer for now, with future plans to drive it with an Arduino Uno.

Design files are on Github for the curious. We’ve featured some similar work before, too, because you really can build anything out of Lego. Video after the break.

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The Rise And The Fall Of The Mail Chute

As the Industrial Age took the world by storm, city centers became burgeoning hubs of commerce and activity. New offices and apartments were built higher and higher as density increased and skylines grew ever upwards. One could live and work at height, but this created a simple inconvenience—if you wanted to send any mail, you had to go all the way down to ground level.

In true American fashion, this minor inconvenience would not be allowed to stand. A simple invention would solve the problem, only to later fall out of vogue as technology and safety standards moved on. Today, we explore the rise and fall of the humble mail chute.

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Digitally-Converted Leica Gets A 64-Megapixel Upgrade

Leica’s film cameras were hugely popular in the 20th century, and remain so with collectors to this day. [Michael Suguitan] has previously had great success converting his classic Leica into a digital one, and now he’s taken the project even further.

[Michael’s] previous work saw him create a so-called “digital back” for the Leica M2. He fitted the classic camera with a Raspberry Pi Zero and a small imaging sensor to effectively turn it into a digital camera, creating what he called the LeicaMPi. Since then, [Michael] has made a range of upgrades to create what he calls the LeicaM2Pi.

The upgrades start with the image sensor. This time around, instead of using a generic Raspberry Pi camera, he’s gone with the fancier ArduCam OwlSight sensor. Boasting a mighty 64 megapixels, it’s still largely compatible with all the same software tools as the first-party cameras, making it both capable and easy to use. With a  crop factor of 3.7x, the camera’s Voigtlander 12mm lens has a much more useful field of view.

Unlike [Michael’s] previous setup, there was also no need to remove the camera’s IR filter to clear the shutter mechanism. This means the new camera is capable of taking natural color photos during the day.  [Michael] also added a flash this time around, controlled by the GPIOs of the Raspberry Pi Zero. The camera also features a much tidier onboard battery via the PiSugar module, which can be easily recharged with a USB-C cable.

If you’ve ever thought about converting an old-school film camera into a digital shooter, [Michael’s] work might serve as a great jumping off point. We’ve seen it done with DSLRs, before, too! Video after the break.

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