Wireless MIDI Controller Has Lots Of Knobs

We live in a golden age for MIDI controllers. [rheslip]’s contribution to the milieu is a twisty take on the format, in that it’s covered in an array of knobs. Thus the name—Twisty 2. 

The controller can be built using the Raspberry Pi Pico or Pico 2. It’s set up to read a 4×4 array of clickable encoders, plus two bonus control knobs to make 18 in total, which are read via a 74HC4067 analog mux chip. There’s also an SK6812 RGB LED for each encoder, and an OLED display for showing status information. MIDI output is via USB, or, if you purchased the W variant of the Pi Pico/Pico 2, it can operate wirelessly over Bluetooth MIDI instead. The controller is set up to send MIDI CC messages, program changes, or note on/off messages depending on its configuration. Flipping through different modes is handled with the bottom set of encoders and the OLED display.

Few musicians we’ve ever met have told us they learned how to play the encoders, and yet. The cool thing about building your own MIDI controller is you can tune it to suit whatever method of performance strikes your fancy. If the name of this build alone has you inspired, you could always whip up a MIDI controller out of a Twister mat.

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Silica Gel Makes For Better 3D Prints

It’s possible to improve your 3D prints in all kinds of ways. You can tune your printer’s motion, buy better filament, or tinker endlessly with any number of slicer settings. Or, as [Dirt-E-Bikes] explains, you could grab yourself some silica gel.

If you’re unfamiliar with silica gel, it’s that stuff that comes in the “DO NOT EAT” packet when you buy a new pair of shoes. It’s key feature is that it’s hygroscopic—which means it likes to suck up moisture from the atmosphere. When it comes to 3D printing, this is a highly useful property—specifically because it can help keep filament dry. Over time, plastic filament tends to pick up some moisture on its own from the atmosphere, and this tends to interfere with print quality. This can be avoided by storing filament in a sealed or semi-seaeled environment with silica gel. The gel will tend to suck up most of the moisture from the air in the sealed container, helping to keep the filament drier.

[Dirt-E-Bikes] does a great job of explaining how best to integrate silica gel with your filament spools and automatic material changer (if you have one). He also explains the value of color changing silica gel which indicates when the material is saturated with water, as well as how to dry it out for reuse. You can even combine some of the color changing beads with the more common plain white beads recycled from your shoe boxes, since you only need a few colored beads to get an idea of the water content.

We’ve explored other filament drying solutions before, too. Video after the break.

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New Drug Hopes To Treat Sleep Apnea Without Masks

Sleep apnea is a debilitating disease that many sufferers don’t even realize they have. Those afflicted with the condition will regularly stop breathing during sleep as the muscles in their throat relax, sometimes hundreds of times a night. Breathing eventually resumes when the individual’s oxygen supply gets critically low, and the body semi-wakes to restore proper respiration. The disruption to sleep causes serious fatigue and a wide range of other deleterious health effects.

Treatment for sleep apnea has traditionally involved pressurized respiration aids, mechanical devices, or invasive surgeries. However, researchers are now attempting to develop a new drug combination that could solve the problem with pharmaceuticals alone.

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Ordering Pizza On The Nintendo Wii (Again)

The Nintendo Wii first launched in 2006, and quickly became a fixture in living rooms around the world. It offered motion-controlled bowling, some basic internet features, and a pretty decent Zelda game. On top of all that, though, you could also use it to order a pizza, as [Retro Game Attic] demonstrates.

The Wii used to organize different features of the console into “channels.” Way back in the day, you could install the Demae Channel on your Wii in Japan, which would let you order fast food from various outlets using the Demaecan service.

The Demae Channel service was discontinued in 2017. However, it has since been resurrected by WiiLink, which is a homebrew project which replicates the functionality of the original Nintendo WiiConnect 24 and Wi-Fi Connection servers. As it stands, you can load the WiiLink version of the Demae Channel (or Food Channel) on to your Wii, and use it to order pizza from your local Domino’s Pizza. It only works in the United States and Canada right now, and there are no other restaurants available, at least until further development is completed to add JustEat compatibility. It’s not entirely clear how much of the functionality was recreated from the original Demae Channel; what is clear is that plenty of custom development has been done on the WiiLink version to integrate it with modern delivery services.

What’s so exciting about this is how well it actually works. The app perfectly nails the classic Wii Channel visual style. It also seems to integrate well with the Domino’s API for digital orders, even displaying simple updates on holiday opening hours and order times. Pricing data and images of the pizzas are all available right in the app, and you can even make modifications. It might be a gimmick… but it actually works. Notably, though, the app avoids any stickiness with handling payment—thankfully, pay-on-delivery is still legitimate in the pizza world in 2026.

Will this revolutionize how you order pizza on a daily basis? Probably not. Is it one of the coolest Wii hacks we’ve seen in a while? Undeniably. Video after the break.

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Driving A DAC Real Fast With A Microcontroller

Normally, if you want to blast out samples to a DAC in a hurry, you’d rely on an FPGA, what with their penchant for doing things very quicky and in parallel. However, [Anabit] figured out a way to do the same thing with a microcontroller, thanks to the magic of the Raspberry Pi Pico 2.

The design in question is referred to as the PiWave 150 MS/s Bipolar DAC, and as the name suggests, it’s capable of delivering a full 150 million samples per second with 10, 12, or 14 bits of resolution. Achieving that with a microcontroller would normally be pretty difficult. In regular linear operation, it’s hard to clock bits out to GPIO pins at that sort of speed. However, the Raspberry Pi Pico 2 serves as a special case in this regard, thanks to its Programmable I/O (PIO) subsystem. It’s a state machine, able to be programmed to handle certain tasks entirely independently from the microcontroller’s main core itself, and can do simple parallel tasks very quickly. Since it can grab data from RAM and truck it out to a bank of GPIO pins in a single clock cycle, it’s perfect for trucking out data to a DAC in parallel at great speed. The Pi Pico 2’s clock rate tops out at 150 MHz, which delivers the impressive 150 MS/s sample rate.

The explainer video is a great primer on how this commodity microcontroller is set up to perform this feat in detail. If you’re trying for accuracy over speed, we’ve explored solutions for that as well. Video after the break.

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Fiber Optic Lamp Modified To Be Scarily Bright

[Brainiac75] is a fan of fiber optic lamps, except for one thing—they’re often remarkably dim. Thus, they set out to hack the technology to deliver terrifying amounts of light while still retaining their quirky charm.

Older fiber optic lamps use a dim filament lamp or halogen lamp to light them up. They also often feature a spinning color disk to vary the light patterns, which does have the side effect of absorbing some of the already-limited light output.

When it came to upgrading his own decades-old lamp, [Braniac75] decided to initially stick within the specs of the original halogen lamp. The fixture was rated for 12 volts at 5 watts, with a GU4/GZ4 compatible base, and white light was desired so the color wheel could still do its thing.  Swapping out the original 5 W halogen for a 2.5 W LED unit brought a big upgrade in brightness, since the latter is roughly equivalent to a 20 W halogen in light output. Upgrading to a 4.2 W LED pushed things even further, greatly improving the look of the lamp.

The video also explores modding a modern fiber optic lamp, too. It was incredibly cheap, running off batteries and using a single color-changing LED to illuminate the fibers. [Braniac75] decided to try illuminating the plastic fibers with an RGB stage lighting laser rig—namely, the LaserCube Ultra 7.5 W from Wicked Lasers. With this kind of juice, the fiber lamp is eye-searingly bright, quite literally, and difficult to film. However, with the laser output dialed way down, the lamp looks amazing—with rich saturated colors dancing across the fiber bundle as the lasers do their thing.

If you’ve ever wanted to build a fiber lamp that doesn’t look like a cheap gimmick, now you know how. We’ve looked at weird applications for these lamps before, too.

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Nixie Gear Indicator Shines Bright

When you’re driving a car with a stickshift, it’s pretty easy to keep track of which gear you’re in. That can be a little bit more difficult on something like a motorcycle with a sequential shifter. [decogabry] built a neat gearshift indicator to solve this issue.

An ESP32 devboard is used as the brain of the build. It’s paired with an ELM327 dongle over Bluetooth, which is able to hook into the bike’s ODB diagnostic port to pick up data like engine RPM, wheel speed, and coolant temperature. The first two factors are combined in order to calculate the current gear, since the ratio between engine RPM and wheel speed is determined directly by the gear selection. The ESP32 then commands a Philips ZM1020 Nixie tube to display the gear, driving it via a small nest of MPSA42 transistors. A separate self-contained power supply module is used to take the bike’s 12 volt supply up to the 170 volts needed to run the tube. There is also a small four-digit display used to show status information, RPM, and engine temperature.

Notably,  [decogabry] made this build rather flexible, to suit any bike it might be installed upon. The gear ratios are not hard coded in software. Instead, there is a simple learning routine that runs the first time the system is powered up, which compares RPM and wheel speed during a steady-state ride and saves the ratios to flash.

We’ve featured projects before that used different techniques to achieve similar ends. It’s also interesting to speculate as to whether there’s a motorcycle vintage enough to suit a Nixie display while still having an ODB interface on board as standard. Meanwhile, if you’re cooking up your own neat automotive builds, don’t hesitate to drop us a line.