You don’t need fancy ICs and DACs to build a sound card for a PC. As [serdef]’s build over on hackaday.io shows, all you really need is a bunch of resistors. [serdef] built a clone of a sound card released for PC in the 80s, but with a few improvements. This mess of resistors features the best 8-bit sound you can get with a low-pass filter, volume divider, and a handy DB-25 connector.
The design of this LPT0 sound card is pretty much the same as when it was introduced to the world as the Covox Speech Thing. This ‘sound card’ was designed to clip onto the parallel port of a computer and send the 8-bit I/O of this port through a resistor ladder. Plug a pair of speakers into this thing, and you have a sound card that is completely made out of resistors. It was cheap, and in the demoscene it was popular.
There are a lot of amazing demos out there using this resistor DAC thing, and [serdef] has videos of his project playing a lot of them. You can check that out below.
Helsinki has a strong underground Heavy Metal scene, so what better way to show it off than to have listeners literally unearth the local sounds themselves with converted metal detectors that play, naturally, Metal? [Steve Maher] built these modified detectors and handed them to a bunch of participants who went on exploratory walks around the city. The tracks from local bands changed as the user moved from one concealed metallic object to the other to create the experience of discovering the hidden soundscape of the land. Continue reading “Heavy Metal Detectors”→
We have all at some point have made a flashlight. It used to be a staple of childhood electronics, the screw-in bulb in a holder, and a cycle lamp battery. If you were a particularly accomplished youthful hacker you might even have fitted a proper switch, otherwise, you probably made do with a bent paperclip and a drawing pin.
So you might think that flashlights offer no challenges, after all, how many ways can you connect a bulb or an LED to a battery? [Peter Fröhlich] though has a project that should put those thoughts out of your mind. It uses a power LED driven by a TI TPS61165 boost driver, with an ATTiny44 microcontroller providing control, battery sensing, and button interface. The result is a dimmable flashlight in a 3D printed case housing both control circuitry and a single 18650 cell which he sourced from a dead laptop. Suddenly that bent paperclip doesn’t cut it anymore.
The result is a flashlight that is the equal of any commercial offering, and quite possibly better than most of them. You can build one yourself, given that he’s published the physical files necessary, but probably because this is a work in progress there are as yet no software files.
Blinky LED projects: we just can’t get enough of them. But anyone who’s stared a WS2812 straight in the face knows that the secret sauce that takes a good LED project and makes it great is the diffuser. Without a diffuser, colors don’t blend and LEDs are just tiny, blinding points of light. The ideal diffuser scrambles the photons around and spreads them out between LED and your eye, so that you can’t tell exactly where they originated.
We’re going to try to pay the diffuser its due, and hopefully you’ll get some inspiration for your next project from scrolling through what we found. But this is an “Ask Hacakday”, so here’s the question up front: what awesome LED diffusion tricks are we missing, what’s your favorite, and why?
Last weekend was great for science and technology. While thousands of people took to the streets to protest anti-intellectualism, a few members of the Hackaday community dug their heels in, turned on the soldering iron, and actually did something about it. This was World Create Day, a community effort to come together and build something that matters. What did these people build? So much awesome stuff.
The Nest I/O in Karachi, Pakistan
The folks at The Nest I/O hackerspace in Karachi, Pakistan had a rather large meetup for World Create Day featuring the finest in laser cut, googly-eyed fighting robots. [Nasir Aziz] hosted a meetup at his favorite hackerspace for people to get together, discuss, and build something for the Hackaday Prize.
The highlight of the meetup was a discussion from EjaadTech, an industrial design firm that graduated from The Nest I/O accelerator. Among the projects invented during World Create Day were a ‘shopping helper drone’ and miniature fighting robots. Useful projects on one hand, awesome projects on the other, just like we like it.
MakerBay in Hong Kong
A solar oven found at MakerBay
MakerBay is a hackerspace located smack in the middle of Hong Kong. Like most hackerspaces, finding a place was a problem, but the folks at MakerBay found something spectacular. They’re zoned industrial, and only a five-minute walk from a train station.
There are quite a few projects sitting around MakerBay including a solar oven that would be pretty dangerous if it were outdoors on a sunny day. Also on deck are prototypes of small sailing vessels with a flexible hull designed to track and contain oil spills. Highlights of World Create Day include upcycled wood construction and a spontaneous piano interlude. I’m surprised I haven’t seen more hackerspaces with a piano; they’re effectively free if you have a truck and a place to store it.
BlenderLab in Lille
While the World Create Day event at the BlenderLab hackerspace in Lille, France didn’t set out to change the world with a project, they did manage to come up with a really neat digital hourglass. The body of this hourglass is made out of laser cut plywood, with the display made out of two LED matrices oriented at a 45-degree angle.
Hackaday NYC
[Zach Freedman] reveals his devious plotWhile World Create Day is a challenge for hackerspaces around the globe to come together and create something that solves a problem, that doesn’t mean there aren’t slightly more official events around the globe. Hackaday set up our own events in New York City, LA, and San Francisco. The New York event was great thanks to our lovely East coast community manager [Shayna] and our hosts at Fat Cat Fab Lab.
[Zach Freedman], one of the regulars at our NYC meetups has an ulterior motive for getting the Fat Cat Fab Lab members to contribute their ideas to the Hackaday Prize: winning the Hackaday Prize would result in donating the winnings to the Fab Lab. It’s a brilliant and devious plot we very much recommend.
Tell us about your World Create Day
There were many more events going on around the globe last weekend, and we want to hear about how your World Create Day went. We’ll be covering more of the events of last weekend in the coming days, so make sure to add your pictures, stories, and links to the projects you started on your World Create Day event page on Hackaday.io. Event organizers are going to get some super awesome swag for making that effort.
We will all be used to malicious software, computers and operating systems compromised by viruses, worms, or Trojans. It has become a fact of life, and a whole industry of virus checking software exists to help users defend against it.
Underlying our concerns about malicious software is an assumption that the hardware is inviolate, the computer itself can not be inherently compromised. It’s a false one though, as it is perfectly possible for a processor or other integrated circuit to have a malicious function included in its fabrication. You might think that such functions would not be included by a reputable chip manufacturer, and you’d be right. Unfortunately though because the high cost of chip fabrication means that the semiconductor industry is a web of third-party fabrication houses, there are many opportunities during which extra components can be inserted before the chips are manufactured. University of Michigan researchers have produced a paper on the subject (PDF) detailing a particularly clever attack on a processor that minimizes the number of components required through clever use of a FET gate in a capacitive charge pump.
On-chip backdoors have to be physically stealthy, difficult to trigger accidentally, and easy to trigger by those in the know. Their designers will find a line that changes logic state rarely, and enact a counter on it such that when they trigger it to change state a certain number of times that would never happen accidentally, the exploit is triggered. In the past these counters have been traditional logic circuitry, an effective approach but one that leaves a significant footprint of extra components on the chip for which space must be found, and which can become obvious when the chip is inspected through a microscope.
The University of Michigan backdoor is not a counter but an analog charge pump. Every time its input is toggled, a small amount of charge is stored on the capacitor formed by the gate of a transistor, and eventually its voltage reaches a logic level such that an attack circuit can be triggered. They attached it to the divide-by-zero flag line of an OR1200 open-source processor, from which they could easily trigger it by repeatedly dividing by zero. The beauty of this circuit is both that it uses very few components so can hide more easily, and that the charge leaks away with time so it can not persist in a state likely to be accidentally triggered.
The best hardware hacks are those that are simple, novel, and push a device into doing something it would not otherwise have done. This one has all that, for which we take our hats off to the Michigan team.
I dig cars, and I do car stuff. I started fairly late in life, though, and I’m only just starting to get into the whole modification thing. Now, as far as automobiles go, you can pretty much do anything you set your mind to – engine swaps, drivetrain conversions, you name it – it’s been done. But such jobs require a high level of fabrication skill, automotive knowledge, and often a fully stocked machine shop to match. Those of us new to the scene tend to start a little bit smaller.
So where does one begin? Well, there’s a huge realm of mods that can be done that are generally referred to as “bolt-ons”. This centers around the idea that the install process of the modification is as simple as following a basic set of instructions to unbolt the old hardware and bolt in the upgraded parts. Those that have tread this ground before me will be chuckling at this point – so rarely is a bolt-on ever just a bolt-on. As follows, the journey of my Mazda’s differential upgrade will bear this out.
The car in question, currently known as the “Junkbox MX-5” until it starts running well enough to earn a real name. It somehow looks passable here, but in person I promise you, it looks awful. Credit: Lewin Day
It all started when I bought the car, back in December 2016. I’d just started writing for Hackaday and my humble Daihatsu had, unbeknownst to me, just breathed its last. I’d recently come to the realisation that I wasn’t getting any younger, and despite being obsessed with cars, I’d never actually owned a sports car or driven one in anger. It was time to change. Continue reading “Different Differentials & The Pitfalls Of The Easy Swap”→
