# Dumping Game Boy Cartridges Via The Link Cable Port

When it comes to vintage consoles like the Game Boy, it’s often nice to be able to dump cartridge ROMs for posterity, for archival, and for emulation. To that end, [Francis Stokes] of [Low Byte Productions] whipped up a rather unique method of dumping Game Boy carts via the link cable port.

The method starts by running custom code on the Game Boy, delivered by flash cart. That code loads itself into RAM, and then waits for the user to swap in a cart they wish to dump and press a button. The code then reads the cartridge, byte by byte, sending it out over the link port. To capture the data, [Francis] simply uses a Saleae logic analyzer to do the job. Notably, the error rate was initially super high with this method, until [Francis] realised that cutting down the length of the link cable cut down on noise that was interfering with the signal.

The code is available on GitHub for those interested. There are other ways to dump Game Boy cartridges too, of course.

# How The Turntable Paradox Works

Leave most objects on top of a turntable, and set it spinning, and they’ll fly off in short order. Do the same with a ball, though, and it somehow manages to roll around on top for quite some time without falling off. [Steve Mould] set about unpacking this “Turntable Paradox” in a recent YouTube video.

In the basic case, the fact that the ball rolls is what keeps it on the turntable. As the turntable spins, the ball spins in the opposite direction, as per Newton’s first law of motion. As long as the ball is allowed to roll up to the same speed as the turntable, it will pretty much stay in place in the absence of any other perturbing forces. In the event the ball is nudged along the turntable, though, it quickly ends up in a more complicated circular motion, orbiting in a ratio to the speed of the turntable itself. [Steve] explains the mechanisms at play, and dives into the mathematics behind what’s going on.

Sometimes, demonstrations like these can seem like mere curiosities. However, understanding physical effects like these has been key to the development of all kinds of complicated and fantastical machinery. Video after the break.

# Omniwhegs Are Awesome Times Two

What’s the strangest wheel? The omniwheel. Unless you count whegs — “wheel legs” — as wheels. This research paper from Shanghai Technical University explores a mash-up of the two ideas, where the wheels roll as standard omniwheels until a servo on the axle unfurls them into their whegs configuration. The result? OmniWhegs!

The resulting vehicle is a bit of a departure from the original whegs concept, which used compliant mechanisms which passively balanced the force across the legs. Here, the omniwhegs are rigid and actually use a synchronization routine that you can see in the video embedded below.

If you can’t get enough omniwheels, you’re not alone. Here’s a rare three-wheeler, and here’s an omniwheel made of MDF. We haven’t seen enough whegs-based bots, but OutRunner is pretty astounding, and we think deserves a second look.

We’ve also seen wheels that convert to whegs before, but without the omni.  And we don’t know if that one ever made it out of render-of-a-robot phase.

So kudos to the Shanghai team for taking the strangest possible wheels and actually building them!

# Nanoaetherphone Is A Special MIDI Controller

MIDI controllers can be simple straightforward keyboards, or wild magical devices that seem to snatch notes from the very aether itself. As you might expect from the name, the Nanoaetherphone II is one of the latter.

The device is inspired by the Theremin, and was built to celebrate its 100th anniversary. The Nanoaetherphone II is all about using sensors to capture data from wireless hand-wavey interactions, and turn it into MIDI messages. To this end, it has an LDR sensor for detecting light levels, which determines volume levels. This is actuated by the user’s thumb, blocking the sensor or allowing ambient light to reach it. At the front of the handheld unit, there is also an ultrasonic range sensor. Depending on how close the sensor is to the user’s hand or other object determines the exact note sent by the device. As a MIDI controller, it is intended to be hooked up to an external synthesizer to actually generate sound.

The overall concept isn’t too complicated, and the design makes it easy to pickup and play. We imagine it could even be foolproofed by programming it only to play notes from a given scale or mode, allowing for easy soloing without too many of those ill-tempered blue notes. Jazz enthusiasts might prefer it to just spit out any and all notes, of course.

We love a good MIDI controller around these parts, and we’ve seen everything from knitted models to those made out of old phones. Video after the break.

# Magnet Clock Makes Field Lines Visible

The traditional method for visualizing magnetic fields, which your science teacher probably demonstrated at some point, is to sprinkle some iron filings onto a piece of paper and hold it over a magnet. It’s a bit of a messy process though, and nowadays there’s a more modern method available in the form of magnetic viewing films. These work thanks to tiny nickel particles suspended in an oily medium, and come in very handy if you want to examine, say, the magnetic field pattern of a DC electric motor. [Moritz v. Sivers] had another idea for this magic material however, and used it to make a Magnet Viewing Clock.

The clock’s front panel looks very similar to a large monochrome LCD, but is actually a big slab of magnetic viewing film. Four disks are mounted behind it, each carrying number-shaped magnetic stickers that are cleverly hidden from view. An Arduino Uno keeps track of time through a real-time clock and operates four stepper motors that rotate the number wheels. When they move into position, their magnetic stickers become visible through the film and you can read the time.

The clock’s mechanical parts are 3D printed, while the digits were cut from a sheet of sticky magnetic foil using a vinyl cutter. If you’d like to try making something similar you’re in luck: [Moritz] made the design files and the Arduino sketch available on his GitHub page. Magnetic viewing films are pretty neat things to play with anyway, and can even be used to read hidden messages.

# Self-Assembling Virus Model Is 3D Printed

Sometimes a visual or tactile learning aid can make all the difference to elucidating a concept to an audience. In the case viruses and their methods of self-assembly, [AtomicVirology] made a 3D printed device to demonstrate how they work.

The result of this work is a printed dodecahedron, assembled from multiple components. Each face of the dodecahedron consists of a 5-sided pentagon, and is a separate piece. Each face contains magnets which allow the various faces to stick together. Amazingly, when a bunch of these faces are all thrown into a container and jumbled together, they eventually assemble themselves into complete dodecahedrons.

While it’s no virus, and the parts can’t replicate themselves en masse,  the demonstration is instructive. Viruses themselves self-assemble in a similar fashion, thanks to sub-units that interact with each other in the tumultuous environment of a host cell.

We love a good teaching tool around these parts. 3D printing has the benefit of allowing teachers to create their own such devices with just a few hours spent in some CAD software.

# Massive Mouse Game Mimics Classic Software Crashes

Computer mice come in all kinds of shapes and sizes, but are typically designed to fit in the palm of your hand. While some users with large hands may find standard mice uncomfortably small, we don’t think anyone will ever make that complaint about the humongous peripheral [Felix Fisgus] made for a game called Office Job at the ENIAROF art festival in Marseille. With a length of about two meters we suspect it might be the largest functional computer mouse in existence.

Inside the massive mouse is a wooden pallet with four caster wheels that enable smooth movement in all directions. This motion is detected by an ordinary optical mouse sensor: perhaps surprisingly, these can be used at this enormous scale simply by placing a different lens in front.

As for the mouse button, [Felix] and his colleagues found of that the bottom of an empty five-liter can has a nice “pop” to it and installed one in the front section of the device, hooked up to an ESP32 board that communicates with a computer through Bluetooth.

The mouse connects to an equally huge desktop computer, powered by a Raspberry Pi, on which users play a game that involves clicking on error messages from a wide variety of old and new operating systems. Moving the mouse and pressing its button to hit those dialog boxes is a two-person job, and turns the annoyance of software errors into a competitive game.

Optical mouse sensors are versatile devices: apart from their obvious purpose they can also serve as motion sensors for autonomous vehicles, or even as low-resolution cameras.