hardware

1647 Articles

Complicated And Useless Cancel Each Other Out

March 3, 2021 by 11 Comments

We all know what it means to procrastinate, but what about actively spending time building a useless machine? You have undoubtedly seen the ornamental boxes with a tempting little toggle switch on the top. When you inevitably flip the switch, an actuator pops out from one half of the enclosure with the sole purpose of undoing its own power switch. [Paz Hameiri] took it a step further by adding some [Rube Goldberg] flavor, and with the help of a microcontroller, his levers take their sweet time powering themselves down. (Video after the break.)

We didn’t find any code or diagrams for the project, but if you know the useless machine’s internals, it shouldn’t be any trouble to recreate one for your desk. The most significant design factor is that the switches. Their contacts must be wired in parallel so that the controller has power as long as one is active. How would you spice up the useless machine?

Even though these are called useless machines, they serve the purpose of decoration, conversation-starting, or a way to show off your woodworking and programming skills.

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SVG To Gerber, Without The Pain

March 1, 2021 by 10 Comments

We’ve all marveled at the high quality PCB artwork used within the #BadgeLife and other communities to produce eye-catching designs, but those of you who have dipped your toes in the PCB artwork water will know that it’s hardly an easy process. [Jaseg] may have an answer though with gerbolyze, his software for processing SVG files into Gerber layers or KiCAD footprints.

His impetus for building it came from disappointing experience with other scripts that simply tried to rasterise any SVG they were given, or didn’t fully support the complete SVG spec. It’s designed for minimal preprocessing, allowing for as streamlined a process as possible. It includes a bitmap vectoriser to handle everything that can be thrown at it, and the GitHub repository has full instructions including examples of the output for different settings.

This is the latest in a long progression of enhancements to the PCB art process, but it’s not by any means the first time we’ve ventured down this path. In particular [Brian Benchoff] did a lot of work on the production of multi-colour PCBs.

Sounding The Humble LED

February 27, 2021 by 22 Comments

Here at Hackaday we’re no strangers to the colorful glow of LEDs. But what if there was more to appreciate beneath the surface? Back in 2011 [Windell] over at Evil Mad Scientist dug into a certain variety of LED and discovered they had a song to sing.

Over the last couple decades, you’ve likely encountered the flickering “candle flame” variety of LED. Often found embedded in small plastic candle simulacra they are shaped like typical through hole “gumdrop” style LEDs, but pack some extra magic which causes them to flicker erratically. Coupled with a warm white color temperature the effect isn’t entirely dissimilar to the flickering of a candle flame.

To the Hackaday reader (and [Windell]) the cause of the flickering may be fairly clear, there is an IC embedded in the lens of the LED. See photo at top for an example of how this might look, helpfully magnified by the lens of the LED itself. Looking through the lens the captive die is visible, as well as the bond wires connecting it to the legs and light emitting diode itself. [Windell]’s observation is that together this assembly makes for a somewhat strange electrical component; from the perspective of the circuit it appears to randomly vary the current flowing through the LED.

He includes two interesting demos. One is that by attaching the flickering LED to a BJT he can turn it into a current amplifier and successfully drive a much more powerful 1W LED with the same effect. The other is that  with the power of the amplifier the same flickering LED can drive a buzzer as well. The effect is surprisingly pleasant, though we’d hesitate to call it musical.

For a more recent example of a similar phenomenon with a very different sound, check out out [Emily Velasco]’s playback of a similarly constructed RGB color changing LED, embedded below. We’ve seen optical tools used to decode LED flickers into data streams, but not for audio playback! We have also covered some LED flicker reverse engineering that spills more of the mystery sealed up in these specialized diodes.

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Taking A Capacitor Microphone To The Next Level

February 24, 2021 by 13 Comments

There was a time when a microphone for most people was a cheap plastic affair that probably came for free with their sound card, but in the age of pandemic video streaming no desktop is complete without a chunky model that looks for all the world as though it escaped from a studio. Few people make their own microphones, so the work of [DJJules] in building very high quality condenser microphones is a particularly fascinating read.

A condenser microphone is a capacitor in which one plate is formed by a conductive diaphragm. A bias voltage is supplied to the diaphragm via a resistor, and since the charge on the plate remains constant as its capacitance changes with the sound vibrations, the voltage on the capacitor changes accordingly. This is picked up by a high impedance buffer and from there fed to a normal microphone input. This Instructable uses a commercial condenser microphone capsule, and takes the reader through generating the bias voltage for it before describing the op-amp buffer circuit.

The most interesting part comes at the end, as we’re shown how the sensitivity pattern of a dual-microphone array can be tuned to be omnidirectional, cardoid, or figure-of-eight. This is probably the norm among audio engineers, but we rarely see this sort of insight in our community. We may never build a microphone of our own, but it’s fascinating to see this one from the ground up in the video below the break.

If you’re confused about the difference between a condenser microphone and the more common electret condenser microphone, we have published a guide to that topic. Continue reading “Taking A Capacitor Microphone To The Next Level” →

Custom 3D Printed Vitamins Are Just A Few Clicks Away

February 18, 2021 by 39 Comments

It’s recently come to our attention that a company by the name of Nourished has carved out a niche for themselves by offering made-to-order gummy vitamins produced with their own custom designed 3D printers. Customers can either select from an array of pre-configured “stacks”, or dial in their own seven layers of gelatinous goodness for a completely bespoke supplement.

Now we can’t vouch for whether or not taking a custom supplement like this is any better than just popping a traditional multi-vitamin, but we’ll admit the hardware Nourished has developed is pretty interesting. As briefly seen in the video after the break, large syringes are filled with the seven different vitamin suspensions, and then loaded into what appears to be a heated chamber for extrusion. This is not unlike other food-grade 3D printers we’ve seen, such as the Cocoa Press.

It looks like all of the syringes are being depressed simultaneously with a plate and a pair of beefy lead screws, so it seems the order in which the layers are placed down must be different for each nozzle. A blog post on the company’s site from early last year shows a wildly different machine being used to produce the vitamins, so either their core technology is changing rapidly, or perhaps the printer being used depends on whether they’re running off the customized stacks versus the standard formulations.

Interestingly, this is very similar to a concept floated by the U.S. Army’s Combat Feeding Directorate (CFD) back in 2014. They reasoned that a 3D printer could be used to produce meal bars that were customized for each soldier’s personal nutritional needs. Being largely impractical for the battlefield, the program didn’t get very far. But thanks to consumers who are willing to pay the premium that Nourished is charging for this service, it seems the idea has turned into a lucrative business model.

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Motor Controller Reverse Engineering Releases Smoke

February 5, 2021 by 31 Comments

It may have been designed for a sewing machine, but [Haris Andrianakis] found his imported DC brushed motor was more than up to the challenge of powering his mini lathe. Of course there’s always room for improvement, so he set out to reverse engineer the motor’s controller to implement a few tweaks he had in mind. Unfortunately, things took an unexpected turn when plugging his AVR programmer into the board’s ISP socket not only released the dreaded Magic Smoke, but actually tripped the breaker and plunged his bench into darkness.

Studying how the Hall-effect sensors in the motor are wired.

Upon closer inspection, it turned out the board has no isolation between the high voltage side and its digital logic. When [Haris] connected his computer to it via the programmer, the 330 VDC coming from the controller’s rectifier shorted through the USB bus and tripped the Earth-leakage circuit breaker (ELCB). The good news is that his computer survived the ordeal, and even the board itself seemed intact. But the shock must have been too much for the microcontroller he was attempting to interface with, as the controller no longer functioned.

Now fully committed, [Haris] started mapping out the rest of the controller section by section. In the write-up on his blog, he visually masks off the various areas of the PCB so readers have an easier time following along and understanding how the schematics relate to the physical board. It’s a nice touch, and a trick worth keeping in mind during your own reverse engineering adventures.

In the end, [Haris] seems to have a good handle on what the majority of the components are up to on the board. Which is good, since getting it working again now means replacing the MCU and writing new firmware from scratch. Or perhaps he’ll just take the lessons learned from this controller and spin up his own custom hardware. In either event, we’ll be keeping an eye out for his next post on the subject.

Hacking Hardware Bitcoin Wallets: Extracting The Cryptographic Seed From A Trezor

February 4, 2021 by 30 Comments

It’s long been common wisdom that one of the safest places to keep your cryptocurrency holdings is in a hardware wallet. These are small, portable devices that encrypt your keys and offer a bit more peace of mind than holding your coins in a soft or web wallet.

But of course, as we know, nothing is totally secure.

And we were reminded of this fact by Kraken Security Labs, when they showed us how they bypassed all of the safeguards in a popular wallet, the Trezor, to dump and decrypt it’s seed.

It’s worth noting that the hack does require physical access to the wallet — albeit only about fifteen minutes worth. And by “physical access” we mean that the hack leaves the device thoroughly mutilated. The Kraken team started by desoldering the heart of the wallet, a STM32 processor. They then dropped it into a socket on an interface board, and got to glitching.

The hack relies on an attack known as voltage glitching. Essentially, at a precisely-timed moment during the device’s boot sequence, the supply voltage is fluctuated. This enables the chip’s factory bootloader, which can read out the contents of it’s onboard flash memory. The memory is read-protected, but can be accessed 256 bytes at a time through a second voltage glitch. Neither of these attacks work 100% of the time, so if the device fails to boot or the memory remains locked, the FPGA performing the attacks simply tries again. After enough iterations, the Kraken team was able to fully dump the chip’s flash memory.

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