Three-Conductor Pivot For E-Textiles Is Better Than Wires

February 13, 2019 by 1 Comment

Pivots for e-textiles can seem like a trivial problem. After all, wires and fabrics bend and flex just fine. However, things that are worn on a body can have trickier needs. Snap connectors are the usual way to get both an electrical connection and a pivot point, but they provide only a single conductor. When [KOBAKANT] had a need for a pivoting connection with three electrical conductors, they came up with a design that did exactly that by using a flexible circuit board integrated to a single button snap.

This interesting design is part of a solution to a specific requirement, which is to accurately measure hand movements. The photo shows two strips connected together, which pivot as one. The metal disk near the center is a magnet, and underneath it is a Hall effect sensor. When the wrist bends, the magnet is moved nearer or further from the sensor and the unit flexes and pivots smoothly in response. The brief videos embedded below make it clear how the whole thing works.

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Hack My House: Garage Door Cryptography Meets Raspberry Pi

February 13, 2019 by 57 Comments

Today’s story is one of victory and defeat, of mystery and adventure… It’s time to automate the garage door. Connecting the garage door to the internet was a must on my list of smart home features. Our opener has internet connection capabilities built-in. As you might guess, I’m very skeptical of connecting a device to the internet when I have no control over the software running on it.

The garage door is controlled by a button hung on the garage wall. There is only a pair of wires, so a simple relay should be all that is needed to simulate the button press from a Raspberry Pi. I wired a relay module to a GPIO on the Pi mounted in the garage ceiling, and wrote a quick and dirty test program in Python. Sure enough, the little relay was clicking happily– but the garage door wasn’t budging. Time to troubleshoot. Does the push button still work? *raises the garage door* yep. How about the relay now? *click…click* nope.

You may have figured out by now, but this garage door opener isn’t just a simple momentary contact push button. Yes, that’s a microcontroller, in a garage door button. This sort of scenario calls for forensic equipment more capable than a simple multimeter, and so I turned to Amazon for a USB oscilloscope that could do some limited signal analysis. A device with Linux support was a must, and Pico Technology fit the bill nicely.

Searching for a Secret We Don’t Actually Need

My 2 channel Picotech oscilloscope, the 2204A, finally arrived, and it was time to see what sort of alien technology was in this garage door opener. There are two leads to the button, a ground and a five volt line. When the button is pressed, the microcontroller sends data back over that line by pulling the 5 V line to ground. If this isn’t an implementation of Dallas 1-wire, it’s a very similar concept.

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Western Digital Releases Their RISC-V Cores To The World

February 13, 2019 by 66 Comments

What grew out of a university research project is finally becoming real silicon. RISC-V, the ISA that’s completely Big-O Open, is making inroads in dev boards, Arduino-ish things, and some light Internet of Things things. That’s great and all, but it doesn’t mean anything until you can find RISC-V cores in actual products. The great hope for RISC-V in this regard looks to be Western Digital, manufacturers of storage. They’re going to put RISC-V in all their drives, and they’ve just released their own version of the core, the SweRV.

Last year, Western Digital made the amazing claim that they will transition their consumption of silicon over to RISC-V, putting one Billion RISC-V cores per year into the marketplace. This is huge news, akin to Apple saying they’re not going to bother with ARM anymore. Sure, these cores won’t necessarily be user-facing but at least we’re getting something.

As far as technical specs for the Western Digital SweRV core go, it’s a 32-bit in-order core, with a target implementation process of 28nm, running at 1.8GHz. Performance per MHz is good, and if you want a chip or device to compare the SweRV core to (this is an inexact comparison, because we’re just talking about a core here and not an entire CPU or device), we’re looking at something between a decade-old iPhone or a very early version of the Raspberry Pi and a modern-ish tablet. Again, an inexact comparison, but no direct comparison can be made at this point.

Since Western Digital put the entire design for the SweRV core on Github, you too can download and simulate the core. It’s just slightly less than useless right now, but the design is proven in Verilator; running this on a cheap off-the-shelf FPGA dev board is almost a fool’s errand. However, this does mean there’s progress in bringing RISC-V to the masses, and putting Open cores in a Billion devices a year.

The “Impossible” Tech Behind SpaceX’s New Engine

February 13, 2019 by 92 Comments

Followers of the Church of Elon will no doubt already be aware of SpaceX’s latest technical triumph: the test firing of the first full-scale Raptor engine. Of course, it was hardly a secret. As he often does, Elon has been “leaking” behind the scenes information, pictures, and even video of the event on his Twitter account. Combined with the relative transparency of SpaceX to begin with, this gives us an exceptionally clear look at how literal rocket science is performed at the Hawthorne, California based company.

This openness has been a key part of SpaceX’s popularity on the Internet (that, and the big rockets), but its been especially illuminating in regards to the Raptor. The technology behind this next generation engine, known as “full-flow staged combustion” has for decades been considered all but impossible by the traditional aerospace players. Despite extensive research into the technology by the Soviet Union and the United States, no engine utilizing this complex combustion system has even been flown. Yet, just six years after Elon announced SpaceX was designing the Raptor, they’ve completed their first flight-ready engine.

The full-flow staged combustion engine is often considered the “Holy Grail” of rocketry, as it promises to extract the most possible energy from its liquid propellants. In a field where every ounce is important, being able to squeeze even a few percent more thrust out of the vehicle is worth fighting for. Especially if, like SpaceX, you’re planning on putting these new full-flow engines into the world’s largest operational booster rocket and spacecraft.

But what makes full-flow staged combustion more efficient, and why has it been so difficult to build an engine that utilizes it? To understand that, we’ll need to first take a closer look at more traditional rocket engines, and the design paradigms which have defined them since the very beginning.

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The Life-Changing Magic Of Buying Stuff To Hack

February 13, 2019 by 41 Comments

At the dawn of every new year, many people make resolutions of some sort. Some resolve to live a less materialistic life and trim their possessions, and in our year 2019 this school of thought has been turbocharged by Marie Kondo. Author of book The Life-Changing Magic Of Tidying Up and star of related Netflix show Tidying Up with Marie Kondo, her trend has been credited with a sharp rise in thrift store donations. To the point that some thrift stores are swamped with incoming inventory and struggling to keep up.

Hackers, this is our call to action. We can be the heroes these thrift stores need! New and exciting projects are on the shelves of our local thrift stores waiting for us. We can give a second life to something that no longer sparks joy in others. A child has abandoned their scooter? Give it some serious power. Someone’s heirloom jewel box? Nah, that’s a hard drive enclosure. Simple music instruments? Obviously it needs an Arduino twist. Innocent children’s toy? Fresh nightmare fuel. And that’s before we even get to the electronics section, featuring computers that have been gathering dust for decades and perfect for scratching a retrocomputing itch.

Of course, we recognize that some would choose to go in the other direction, to tidy up their collection of half-finished hacks. Say goodbye those that, if we were honest with ourselves, we are never going to finish. This is great, too, because the goal is to have everything in the hands of people who will appreciate them. If that should spark the next wave of joyous hacks, so much the better.

A Network Attached Radiation Monitor

February 13, 2019 by 25 Comments

It started as a joke, as sometimes these things do. [Marek Więcek] thought building a personal radiation detector would not only give him something to work on, but it would be like having a gadget out of the Fallout games. He would check the data from time to time and have a bit of a laugh. But then things got real. When he started seeing rumors on social media that a nearby nuclear reactor had suffered some kind of radiation leak, his “joke” radiation detector suddenly became serious business.

With the realization that having his own source of detailed environmental data might not be such a bad idea after all, [Marek] has developed a more refined version of his original detector (Google Translate). This small device includes a Geiger counter as well as sensors for more mundane data points such as temperature and barometric pressure. Since it’s intended to be a stationary monitoring device, he even designed it to be directly plugged into an Ethernet network so that it can be polled over TCP/IP.

[Marek] based the design around a Soviet-era STS-5 Geiger tube, and outfitted his board with the high voltage electronics to provide it with the required 400 volts. Temperature, barometric pressure, and humidity are read with the popular Bosch BME280 sensor. If there’s no Ethernet network available, data from the sensors can be stored on either the built-in SPI flash chip or a standard USB flash drive.

The monitor is powered by a PIC32MX270F256B microcontroller with an Ethernet interface provided by the ENC28J60 chip. In practice, [Marek] has a central Raspberry Pi that’s polling the monitors over the network and collecting their data and putting it into a web-based dashboard. He’s happy with this setup, but mentions he has plans to add an LCD display to the board so the values can be read directly off of the device. He also says that a future version might add WiFi for easier deployment in remote areas.

Over the years we’ve seen a fair number of radiation monitors, from solar-powered WiFi-connected units to the incredible work [Radu Motisan] has done building his global network of radiation detectors. It seems hackers would rather not take somebody else’s word for it when it comes to the dangers of radiation.

This Light-Up Sorter Is A Bright Idea

February 12, 2019 by 14 Comments

Sorting out a mountain of screws and other workbench detritus by hand is a task that only appeals to a select few of us. [AdrienR] is not one of those people. He believes the job is better suited to a robot, so he built an intelligent and good-looking machine that does just that.

[Adrien]’s sorting bot is capable of organizing a hodgepodge of parts quickly and effectively. He simply scatters the parts on the light box work surface, illuminates it, and takes a picture with a downward-facing web cam. An algorithm studies the parts and their positions using OpenCV image processing, and sends the triangulation back to the arm so it can pick and place the parts into laser cut boxes using a home brew electromagnet.

[Adrien] calls this a work in progress. He plans to control it with a Raspberry Pi so it can be a standalone unit, and will probably move the parts boxes to the outside curve. Drop yourself past the break to see it sort.

If delta robots are more your sort, this one has balls. Colored balls.

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