Movie-Style Hacking With A Wall Of Glowing Hex

December 20, 2019 by Tom Nardi 21 Comments

Over the years, the media has managed to throw together some pretty ridiculous visual depictions of computer hacking. But perhaps none have gone as far down the road of obfuscation as The Matrix, where the most experienced hackers are able to extract information from a display of cascading green glyphs like a cyberpunk version of reading tea leaves. It’s absolutely ridiculous, with zero basis in reality.

Well, maybe not anymore. Taking a page from these outlandish visions of hacking, [Erik Bosman] has constructed a dedicated hex dump display out of fourteen segment alphanumeric LEDs that looks like it could be pulled from a movie set. But make no mistake, it’s more than just a pretty face. By cleverly varying the brightness of the individual characters, he’s managed to make his so-called “hexboard” completely usable despite the fact that everything’s the same color.

While he says the project is not quite at 100% yet, he’s already released the firmware, computer-side software, and even the PCB design files for anyone who might want to build their own version. Though as you might imagine, it’s quite a tall order.

The display is broken up into segments holding eight Houkem-5421 LED modules apiece, each with its own STM32F030F4 and two TC7258E LED controllers. The bill of materials on this one is a bit intimidating, but when the end result look this good it’s hard to complain.

To build a somewhat smaller version that also features a more retro vibe, you might consider doing something similar by chaining together vintage LED “bubble” displays.

Prusa Dares You To Break Their Latest Printer

December 16, 2019 by Tom Nardi 158 Comments

Two months after its surprise reveal at the 2019 East Coast RepRap Festival, the Prusa Mini has started shipping out to the first wave of early adopters. True to form, with the hardware now officially released to the public, the company has begun the process of releasing the design as open source. In their GitHub repository, owners can already find the KiCad files for the new “Buddy” control board and STLs for the machine’s printable parts.

But even so, not everyone feels that Prusa Research has made the Mini as “open” as its predecessors. Some concerned owners have pointed out that according to the documentation for the Buddy board, they’ll need to physically snap off a section of the PCB so they can flash custom firmware images via Device Firmware Upgrade (DFU) mode. Once this piece of the board has been broken off, which the documentation refers to as the Appendix, Prusa Research will no longer honor any warranty claims for the electronic components of the printer.

For the hardcore tinkerers out there, this news may come as something of a shock. Previous Prusa printers have enjoyed a fairly active firmware development community, and indeed, features that started out as user-developed modifications eventually made their way into the official upstream firmware. What’s more, certain hardware modifications require firmware tweaks to complete.

Prusa Research explains their stance by saying that there’s no way the company can verify the safety of community developed firmware builds. If thermal runaway protections have been disabled or otherwise compromised, the results could be disastrous. We’ve already seen it happen with other printers, so it’s hard to fault them for being cautious here. The company is also quick to point out that the installation of an unofficial firmware has always invalidated the printer’s warranty; physically breaking the board on the Mini is simply meant as a way to ensure the user understands they’re about to leave the beaten path.

How much support is a manufacturer obligated to provide to a user who’s modified their hardware? It’s of course an issue we’ve covered many times before. But here the situation is rather unique, as the user is being told they have to literally break a piece off of their device to unlock certain advanced functionality. If Prusa wanted to prevent users from running alternate firmware entirely they could have done so (or at least tried to), but instead they’ve created a scenario that forces the prospective tinkerer to either back down or fully commit.

So how did Prusa integrate this unusual feature into their brand new 32-bit control board? Perhaps more importantly, how is this going to impact those who want to hack their printers? Let’s find out.

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Software Defined Radio Gets Physical Control

December 12, 2019 by Tom Nardi 16 Comments

Software Defined Radio (SDR) is a great technology, but there’s something so satisfying about spinning a physical knob to cruise the airwaves. Wanting to restore that tactile experience, [Tysonpower] purchased a cheap USB volume knob and set out to get it working with his software. Unfortunately, getting it up and running took a lot more work than you’re probably expecting.

After verifying that the knob worked for volume control on his computer, [Tysonpower] decided to try and pull the firmware from the device’s STM32 microcontroller. Unfortunately, this is where things got tricky. It turned out the chip had Code Protection enabled, so when it was wired up to a programmer and put into DFU mode, the firmware got wiped. Oops.

That left [Tysonpower] with no choice but to write a new firmware from scratch, which naturally required reverse engineering the device’s hardware. Step one was reading up on STM32 development and getting the toolchain working, which paved the way to getting the knob’s LED to blink. A couple more hours worth of work and some multimeter poking later, and he was able to read the knob’s movement. He describes getting USB HID working as a nightmare due to lack of documentation, but eventually he got that sorted out as well.

The end result is a firmware allows the volume knob to mimic a mouse scroll wheel, which can be used for tuning in many SDR packages. But we think the real success story is the experience [Tysonpower] gained with reverse engineering and working with the STM32 platform. After all, sometimes the journey is just as important as the end result. Continue reading “Software Defined Radio Gets Physical Control” →

A STM32 Tonewheel Organ Without A Single Tonewheel

December 5, 2019 by Gerrit Coetzee 7 Comments

The one thing you might be surprised not to find in [Laurent]’s beautiful tonewheel organ build is any tonewheels at all.

Tonewheels were an early way to produce electronic organ sounds: by spinning a toothed wheel at different frequencies and transcending the signal one way or another it was possible to synthesize quite an array of sounds. We like to imagine that they’re all still there in [Laruent]’s organ, albeit very tiny, but the truth is that they’re being synthesized entirely on an STM32 micro controller.

The build itself is beautiful and extremely professional looking. We were unaware that it was possible to buy keybeds for a custom synthesizer, but a model from FATAR sits at the center of the show. There’s a MIDI encoder board and a Nucleo development board inside, tied together with a custom PCB. The UI is an momentary encoder wheel and a display from Mikroelektronika.

You can see and hear this beautiful instrument in the video after the break.

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A Mini Vending Machine To Ramp Up Your Sales

December 3, 2019 by Jenny List No comments

A common sight in the world of hackerspaces is an old vending machine repurposed from hawking soda cans into a one-stop shop for Arduinos or other useful components. [Gabriel D’Espindula]’s mini vending machine may have been originally designed as an exercise for his students and may not be full sized, but we can see it or machines like it taking away some of the demand for those surplus models.

Its construction mimics that of some older 3D printers in using laser-cut ply to form the components of a box. Behind a clear lockable door are the shelves containing the products, at the back of which are continuous rotation servos that will drive the spiral Archimedes screws that eject the products. To the side is a membrane keypad and display, and the whole is drawn together with an STM32 board and an Arduino. It supports both RFID card login and keyboard login, and though it’s not finished we can see it forming the basis of a very useful system.

He’s posted the most recent progress in the form of a video that we’ve placed below the break. All the various files are available for download, so should you fancy one yourself then you have a good chance of success.

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This RGB Tree Has Its Roots In A PCB

November 18, 2019 by Gerrit Coetzee 1 Comment

[Paczkaexpress]’s RGB tree is a mix of clever building techniques and artistic form that come together into quite a beautiful sculpture.

The branches of his tree are made from strands of enameled copper wire capped with an RGB LED and terminated in a female header. The separate wires are all wound and sculpted into the form of a tree. The wire is covered in a very thin layer of plastic, which we highly recommend observing under a microscope, that allow it to maintain a uniform and reflective copper color without shorting, adding to the effect.

The part we found an especially pleasing mix of form and function was how the “roots” of the tree clicked home in the PCB base. The PCB holds the STM32, power components, and an LED Driver. It doesn’t hide how the magic works, and the tree really does get its nutrients from the soil it’s planted in. This would be a fun kit to build. Very clever and you can see the final effect after the break.

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World’s Smallest MIDI Synth, Now Even Better

October 28, 2019 by Dan Maloney 6 Comments

We’re pretty sure there’s no internationally recognized arbiter of records like “World’s smallest full-featured polyphonic stereo MIDI synthesizer that fits in a DIN shell”. If there isn’t, there sure should be, and we’re pretty sure [mitxela]’s Flash-Synth would hold that particular record.

This is one of those lessons that some people just can’t leave a challenge alone. First [mitxela] built a MIDI synthesizer into a DIN connector, then a couple of months later he made a somewhat more streamlined version. While both were feats of engineering derring-do, neither was entirely satisfactory. With only square wave synthesis and a limit of eight voices, plus some unpleasant audio issues and a total lack of manufacturability, the next challenge was clear.

We won’t pretend to follow all the audio arcana, of which the video below and the build log have plenty, but the technical achievement is obvious enough. The Flash-Synth has an STM32, a tantalum SMD filter capacitor that dwarfs it, and a few support components on a flexible PCB that folds back on itself twice. This bit of circuit origami is connected to a 5-pin DIN plug and stuffed into the connector’s shell, which in turn mates to a custom-machined metal housing. A stereo audio jack lives at the other end of the assembly, and the whole synth is powered parasitically off the MIDI port.

The first half of the video below is mostly a demo that proves the synth sounds great and can do just about anything; skip to the 22-minute mark for the gory build details. Suffice it to say that [mitxela]’s past experience with ludicrous scale soldering served him well here.

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