A graphing calculator with a 3D-printed enclosure, with a circuit board next to it

2022 Cyberdeck Contest: The Galdeano Is More Than A Graphing Calculator

September 15, 2022 by 14 Comments

Graphing calculators have evolved from expensive playthings for rich nerds to everyday tools for high schoolers worldwide. Even though teenagers nowadays carry powerful internet-connected computers in their pockets, math teachers often prefer them to use a clunky Z80-powered calculator in class, if only because their limited performance reduces the potential for distraction. The worst thing a lazy student can do is play a simple game like Snake or Tetris.

But what if you’re not a student anymore and you want a graphing calculator that has up-to-date hardware and infinite customizability in software? Look no further than [Angel Cabello]’s Galdeano, a handheld that has all the features of a modern graphing calculator plus a lot more. The heart of the device is an ESP32, which sits on a custom PCB that also holds a 6×7 array of push-buttons and a 320×240 touch-sensitive color display. It can be powered through a lithium-polymer battery or, like a classic calculator, through four AAA cells. The entire thing is housed in a 3D printed enclosure with color-coded buttons indicating various built-in functions.

The ESP32 runs MicroPython along with a symbolic math engine called Eigenmath. This enables the Galdeano to  manipulate expressions, perform integration and differentiation, and plot functions. Porting Eigenmath to a memory-constrained platform like the ESP32 was quite a challenge and required a few workarounds, including a memory partition scheme and even a custom compact font with mathematical symbols.

Thanks to the flexibility of MicroPython and the ESP’s WiFi system, the Galdeano is not limited to implementing a calculator: it can also perform various general-purpose tasks ranging from file editing to controlling a set of smart light bulbs. The project page doesn’t mention any games yet, but we’re sure it won’t take long before someone ports Tetris to this system as well.

Of course, even classroom-grade calculators can be pushed to do much more than their designers intended: they can receive GPS signals, run Debian or even perform ray tracing. If you’re looking for a powerful open-source calculator, this BeagleBoard-based machine runs the R statistical computing environment.

Continue reading “2022 Cyberdeck Contest: The Galdeano Is More Than A Graphing Calculator” →

Fork And Run: The Definitive Guide To Getting Started With Multiprocessing

September 15, 2022 by 23 Comments

Since the early 2000s, the CPU industry has shifted from raw clock speed to core counts. Pat Gelsinger famously took the stage in 2002 and gave the talk the industry needed, stating processors needed specialty silicon or multiple cores to reduce power requirements and spread heat. A few years later, the Core series was introduced with two or four-core configurations to compete with the AMD Athlon 64 x2.

Nowadays, we’re seeing heterogeneous chip designs with big and little cores, chiplets, and other crazy fabrication techniques that are fundamentally the same concept: spread the thermal load across multiple pieces of silicon. This writer is willing to put good money into betting that you’ll see consumer desktop machines with 32 physical cores in less than five years. It might be hard to believe, but a 2013 Intel Haswell i7 came with just four cores compared to the twenty you’ll get in an i7 today. Even an ESP32 has two cores with support in FreeRTOS for pinning tasks to different cores. With so many cores, how to even write software for that? What’s the difference between processes and threads? How does this all work in straight vanilla C98?

Continue reading “Fork And Run: The Definitive Guide To Getting Started With Multiprocessing” →

This Simple Light-Controlled Synth Has A Surprisingly Rich Sound

September 15, 2022 by 5 Comments

Audio synthesizers can range from vast racks of equipment with modules stitched together by a web of patch cords to a couple of 555s wired together in an Atari punk arrangement. This light-controlled synth comes in closer to the lower extreme of that range, but packs a sonic punch that belies its simplicity.

The project is the latest version of [lonesoulsurfer]’s “Moog Light Synthesizer,” which shares a lot of the circuitry found in his first version a couple of years ago. This one has a lot of bells and whistles, but it all starts with a PWM oscillator that contributes to the mean, growling quality of its sound. There’s also a low-pass filter that’s controlled by a couple of light-dependent resistors, which can be played by blocking them off with a fingertip. A couple of inverters form a drone oscillator that can be switched into the circuit, as well as a 555-based arpeggiator to chop things up a bit.

All those circuits, as well as support for a thirteen-key keyboard, live on one custom PCB. There’s also an off-the-shelf echo/reverb module that’s been significantly hacked to add to the richness of the sound. The custom wood and acrylic case make the whole thing look as good as it sounds.

We noted that [lonesoulsurfer]’s previous “Box of Beezz” drone synth seemed to evoke parts of the “THX Deep Note” at times; similarly, some of the sounds of this synth sound like they’d come from the soundtrack of a [Christopher Nolan] film  — check it out in the video below.

Continue reading “This Simple Light-Controlled Synth Has A Surprisingly Rich Sound” →

Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The Hexagonal Keyboard

September 15, 2022 by 16 Comments

Well, I didn’t mean to take the whole summer off from Keebin’, it just kind of happened that way. You’d think it would have been #13 that tripped me up, but we ain’t even there yet — this is only the twelfth edition. I kept thinking I should write one and it just wasn’t happening, until I got a tip from [s.ol bekic] about their stunning hexagonal keycaps and the journey toward making an open-source 12-key macropad featuring same.

But let’s back up a bit. Originally, [s.ol] designed a totally sick hybrid MIDI-and-typing keyboard from scratch, which you can see in this short video. It glows, it splits in half, and it snaps back together again quite satisfyingly. And you probably noticed the hexagonal keycaps that look like they might be printed or milled, or perhaps even printed and then milled.

In actuality, [s.ol] threw all the processes at this keycap project — milling, molding and casting, and 3D printing. None of them worked well enough to get much past the prototype stage, but in the end, [s.ol] joined forces with fkcaps.com to create and offer an injection-molded version that I’d really, really like to rock my fingertips around in. Good thing I can pick some up for cheap.

Of course, the real process was all the learning [s.ol] did along the way — both in the early days of making the hybrid keyboard, and after teaming up with fkcaps to make the keycaps and the accompanying macropad into real products. And that was after all the design work it took to get this newfangled honeycomb configuration right.

In case you’re wondering, these are meant for only Kailh chocs, but no matter the switch, the spacing is really important because of all the possible points of friction introduced by the design. Be sure to check out the keycap docs page, macropad docs page, and this gallery of keycaps and macropads.

Continue reading “Keebin’ With Kristina: The One With The Hexagonal Keyboard” →

Billet Machining A Special Xbox

September 15, 2022 by 12 Comments

The world of console modding has delivered us some amazing projects over the years, usually rendering an original into a completely different form factor. [Modified] has done a special bit of console modding on an Xbox Series X, with the unusual result of keeping exactly the same form factor. What makes it special? His Series X has been given a new case, almost identical to the original, but instead of molded plastic it’s machined entirely from a single billet of aluminium stock.

From one perspective it’s a slightly crazy endeavor — pushing the limits of his mill to remove 90% of the stock. But from another it’s an interesting tale of how to approach such a project, of the challenges in reaching further into a workpiece than the tooling is designed for, and also of the cooling for the Xbox itself. Sure he could have made it from aluminium plate and screwed it together, but in doing so he’d have denied us the chance to follow a machining adventure.

The result is an Xbox that’s nominally the same as when it left the factory, but which looks so much cooler. Oddly the aluminum doesn’t act as a heatsink because the console is air-cooled, but particularly on the bottom there are more holes than were found in the original. On the front is an engraving of Master Chief from Halo 2‘s cover art which really puts the finishing touch on the build — though we wonder whether it might benefit from a little resin to make it stand out a bit.

Hungry for more Series X case mods? They don’t come bigger than this one!

Continue reading “Billet Machining A Special Xbox” →

A hand holds a round disc of noodles wrapped in a translucent film with herb specs embedded in it.

Reimagined Ramen Comes In Edible Package

September 15, 2022 by 31 Comments

Hackers and college students alike reach for ramen when they want to fuel up on a budget, but, if you’re concerned about packaging waste, the plastic film and foil packets start to weigh on your conscience. [Holly Grounds] was sick of this compromise and came up with a way to have your packaging and eat it too.

[Holly] first experimented with different bioplastics until she developed a recipe for “an edible, tasteless starch-based bioplastic, that dissolves in contact with boiling water.” With that accomplished, she next integrated flavoring into the bioplastic wrapper so that there’s no foil packet. She found that herbs and spices worked, but larger solids like shrimp couldn’t be incorporated into the film.

For the finishing touch, she fashioned the noodles into a disk so they fit better in a bowl for cooking. To cook the noodles, you remove a puck from the wax paper sleeve holding multiple servings, add boiling water, stir, and enjoy. [Holly] says that her ramen packets are quicker to prepare than existing packets since there are fewer steps and the shape is optimized for cooking. That’s a win-win for the planet and convenience.

If you want to see another pasta packaging marvel, we’ve previously covered Flat Pack Pasta. Have your own project to reduce packaging waste? Submit it to the Save the World Wildcard round of the Hackaday Prize which closes on October 16th!

Making A Tape Echo The Traditional Way

September 14, 2022 by 12 Comments

[Juan Nicola] has taken inspiration from the musician hackers of old and re-purposed a reel-to-reel tape recorder into a tape-echo for his guitar with a built-in valve amplifier (video in Spanish).

The principle is to record the sound of the guitar onto a piece of moving magnetic tape, then to read it back again a short time later.  This signal is mixed with the live input and re-recorded back onto the tape further back.  The effect is heard as an echo, and this approach was very popular before digital effects became readily available.

[Juan] installed a new read-head onto his Grundig TK40 and managed to find a suitable mechanical arrangement to keep it all in place.  He has since updated the project by moving to a tape loop, allowing an infinite play-time by re-using the same piece of tape over and over.

Turning tape machines into echo effects is not a new idea, and we’ve shown a few of them over the years, but every one is slightly different!

Both versions are shown after the break.  YouTube closed-caption auto-translate might come in handy here for non-Spanish speakers.

Continue reading “Making A Tape Echo The Traditional Way” →