Teensy

244 Articles

MIT’s Knitted Keyboard Is Quite A Flexible MIDI Controller

June 30, 2021 by 7 Comments

There are only so many ways to make noise on standard instruments such as acoustic pianos. Their rigidity and inputs just don’t allow for a super-wide range of expression. On the other hand, if you knit your interface together, the possibilities are nearly endless. MIT’s new and improved knitted keyboard is an instrument like none other — it responds to touch, pressure, and continuous proximity, meaning that you can play it like a keyboard, a theremin, and something that is somewhere in between the two. Because it’s a MIDI interface, it can ultimately sound like any instrument you’ve got available in software.

The silver keys of this five-octave interface are made of conductive yarn, and the blue background is regular polyester yarn. Underneath that is a conductive knit layer to complete the key circuits, and a piezo-resistive knit layer that responds to pressure and stretch. It runs on a Teensy 4.0 and uses five MPR121 proximity/touch controllers, one per octave.

The really exciting thing about this keyboard is its musical (and physical) versatility. As you might expect, the keyboard takes discrete inputs from keystrokes, but it also takes continuous input from hovering and waving via the proximity sensors, and goes even further by taking physical input from squeezing, pulling, stretching, and twisting the conductive yarns that make up the keys. This means it takes aftertouch (pressure applied after initial contact) into account —  something that isn’t possible with most regular instruments. And since this keyboard is mostly yarn and fabric, you can roll it up and take it anywhere, or wrap it around your neck for a varied soundscape.

If you’re looking for more detail, check out the paper for the previous version (PDF), which also used thermochromic yarn to show different colors for various modes of play using a heating element. With the new version, [Irmandy Wicaksono] and team sought to improve the sensing modalities, knitted aesthetics, and the overall tactility of the keyboard. We love both versions! Be sure to check it out after the break.

Want to play around with capacitive touch sensors without leaving the house for parts? Make your own from paper and aluminum foil.

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Two-Key Keyboard Build Log Starts Small, But Thinks Big

January 23, 2021 by 3 Comments

Interested in making a custom keyboard, but unsure where to start? Good news, because [Jared]’s build log for an adorable “2% Milk” two-key mini-keyboard covers everything you need to know about making a custom keyboard, including how to add optional RGB lighting. The only difference is that it gets done in a smaller and cheaper package than jumping directly in with a full-size DIY keyboard.

[Jared] is definitely no stranger to custom keyboard work, but when he saw parts for a two-key “2% Milk” keyboard for sale online, he simply couldn’t resist. Luckily for us, he took plenty of photos and his build log makes an excellent tutorial for anyone who wants to get into custom keyboards by starting small.

The hardware elements are clear by looking at photos, but what about the software? For that, [Jared] uses a Teensy  Pro Micro clone running QMK, an open source project for driving and configuring custom input devices. QMK drives tiny devices like the 2% Milk just as easily as it does larger ones, so following [Jared]’s build log therefore conveys exactly the same familiarity that would be needed to work on a bigger keyboard, which is part of what makes it such a great project to document.

Interested in going a little deeper down the custom keyboard rabbit hole? You can go entirely DIY, but there’s also no need to roll everything from scratch. It’s possible to buy most of the parts and treat the project like a kit, and Hackaday’s own [Kristina Panos] is here to tell you all about what that was like.

A Smart Speaker That Reminds You It’s Listening

October 15, 2020 by 20 Comments

[markw2k9] has an Alexa device that sits in his kitchen and decided it was time to spruce it up with some rather uncanny eyes. With some inspiration from the Adafruit Uncanny Eyes project, which displays similar animated eyes, [markw2k9] designed a 3d printed shell that goes on top of a 2nd generation Amazon Echo. A teensy 3.2 powers two OLED displays and monitors the light ring to know when to turn the lights on and show that your smart speaker is listening. The eyes look around in a shifty sort of manner. Light from the echo’s LED ring is diffused through a piece of plexiglass that was lightly sanded on the outside ring and the eye lenses are 30mm cabochons (a glass lens often used for jewelry).

One hiccup is that the ring on the Echo will glow in a steady pattern when there’s a notification. As this would cause the OLEDs to be on almost continuously and concerned for the lifetime of the OLED panels, the decision was made to detect this condition in the state machine and go into a timeout state. With that issue solved, the whole thing came together nicely. Where this project really shines is the design and execution. The case is sleek PLA and the whole thing looks professional.

We’ve seen a few other projects inspired by the animated eyes project such as this Halloween themed robot that is honestly quite terrifying. The software and STL files for the smart speaker’s eyes are on Github and Thingiverse.

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Spin The Video Track With A Mechanical Flair

October 12, 2020 by 16 Comments

One of the most difficult user interfaces to get right is video editing. It is complex and fiddly with large amounts of precision required even after four or five hours of straight editing. Seeking to bring some of that interface out into the real world, [Zack Freedman] built a mechanical video editing keyboard.

The keyboard in question features popular shortcuts and keys to breeze through different parts of editing. The biggest feature is, of course, the large scrubbing knob, allowing [Zack] to fly through long video with precision. We’ve seen our fair share of mechanical keyboards that aren’t traditional keyboards on Hackaday before, such as this number pad or this macro pad.

One of the unique constraints of this project was the fact that Zack had a deadline of two days. This self-imposed deadline was to help focus the work and drive it towards completion. This meant that it had to be designed in such a way that roadblocks or troublesome features could be designed around or cut out altogether. At its heart, this project is just 14 mechanical switches, 4 potentiometers, and a Teensy to drive it all. It is the design, prototyping, and thought that went into this project that makes it noteworthy. There are plenty of lessons here about how to manage a project’s timeline and advice about how to actually finish it.

Code, STL’s, diagrams, and instructions are all on his GitHub.

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Fat Bottomed-Keebs, You Make The Clackin’ World Go Round

October 9, 2020 by 24 Comments

Depending on the circles you run in, it can seem like the mechanical keyboard community is all about reduced layouts, and keebs without ten-keys are about as big as it gets. But trust us, there’s plenty of love out there for the bigger ‘boards like [Ben]’s tasty fat-bottomed keyboard. Man oh man, what a delicious slab of throwback to the days when keyboards doubled as melee weapons.

More specifically, this is a 199-key modified Sun Type 5 layout. It runs on two Teensy 2.0s — one for the keyboard matrix, and one for everything else. [Ben] made the metal enclosure entirely by hand without a CNC or laser cutter. While I don’t personally care for linear switches, I have mad respect for these, which are vintage Cherry Blacks pulled from various 1980s AT/XT boards. That 10-key island on the left is dedicated to elementary macros like undo/redo, cut/copy/paste, and open/close/save.

We absolutely love the gigantic rotary encoders, which give it a bit of a boombox look. There’s even reuse involved here, because the encoder knobs are made from jam jar lids that are stuffed with homemade Sugru. [Ben] can use them to play PONG on the LCD and other games not yet implemented on the everything-else Teensy.

Here’s another Sun-inspired keeb, but this one has a reverse 10-key layout that matches the DTMF phone dial.

A Big Computer Needs A Big Keyboard

September 19, 2020 by 36 Comments

It seems like many keyboard aficionados have been gravitating towards ever smaller boards, but not [Ren]. He’s mostly completed a 433% keyboard with a whopping 450 distinct keys. Using two off the shelf PCBs and Teensy to control it all, this keyboard means you’ll never need to strain to make some awkward chord.

The PCBs have a diode matrix arrangement for 225 keys, which we would have thought was big enough. After all, a Scrabble board has 225 squares, so we assume that’s why the vendor calls them scrabbleboards. Honestly, we’re jealous someone has the desk space for this monster. We were also thinking what other sorts of switch-like sensors you could use with this board. Imagine a home system, for example, with 225 occupancy sensors, each with its own key you could easily read via USB.

There was a time when building your own keyboard of any sort would have been challenging. But now there’s a cottage industry supplying chips, switches, caps, and PCBs to those looking to craft their own custom input devices. The ready availability of 3D printers has also sparked a minor revolution in custom keyboard enclosures and keycaps.

If you’re a fan of the tiny keyboards, we’ve seen some impressive specimens that might catch your fancy. If nothing else, at least they require less soldering. Especially when they only have seven keys.

Thanks [ptkwilliams] for the tip!

LED Art Reveals Itself In Very Slow Motion

September 15, 2020 by 9 Comments

Every bit of film or video you’ve ever seen is a mind trick, an optical illusion of continuous movement based on flashing 24 to 30 slightly different images into your eyes every second. The wetware between your ears can’t deal with all that information individually, so it convinces itself that you’re seeing smooth motion.

But what if you slow down time: dial things back to one frame every 100 seconds, or every 1,000? That’s the idea behind this slow-motion LED art display called, appropriately enough, “Continuum.” It’s the work of [Louis Beaudoin] and it was inspired by the original very-slow-motion movie player and the recent update we featured. But while those players featured e-paper displays for photorealistic images, “Continuum” takes a lower-resolution approach. The display is comprised of four nine HUB75 32×32 RGB LED displays, each with a 5-mm pitch. The resulting 96×96 pixel display fits nicely within an Ikea RIBBA picture frame.

The display is driven by a Teensy 4 and [Louis]’ custom-designed SmartLED Shield that plugs directly into the HUB75s. The rear of the frame is rimmed with APA102 LED strips for an Ambilight-style effect, and the front of the display has a frosted acrylic diffuser. It’s configured to show animated GIFs at anything from 1 frame per second its original framerate to 1,000 seconds per frame times slower, the latter resulting in an image that looks static unless you revisit it sometime later. [Louis] takes full advantage of the Teensy’s processing power to smoothly transition between each pair of frames, and the whole effect is quite wonderful. The video below captures it as best it can, but we imagine this is something best seen in person.

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