Inside Smart Meters Hack Chat

April 12, 2021 by 39 Comments

Join us on Wednesday, April 14 at noon Pacific for the Inside Smart Meters Hack Chat with [Hash]!

That electrical meter on the side of your house might not look like it, but it’s pretty packed with technology. What was once a simple electromechanical device that a human would have to read in person is now a node on a far-flung network. Not only does your meter total up the amount of electricity you use, but it also talks to other meters in the neighborhood, sending data skipping across town to routers that you might never have noticed as it makes its way back to the utility. And the smartest of smart meters not only know how much electricity you’re using, but they can also tease information about which appliances are being used simply by monitoring patterns of usage.

While all this sounds great for utility companies, what does it mean for the customers? What are the implications of having a network of smart meters all talking to each other wirelessly? Are these devices vulnerable to attack? Have they been engineered to be as difficult to exploit as something should be when it’s designed to be in service for 15 years or more?

These questions and more burn within [Hash], a hardware hacker and security researcher who runs the RECESSIM reverse-engineering wiki. He’s been inside a smart meter or two and has shared a lot of what he has learned on the wiki and with some in-depth YouTube videos. He’ll stop by the Hack Chat to discuss what he’s learned about the internals of smart meters, how they work, and where they may be vulnerable to attack.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, April 14 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.
Continue reading “Inside Smart Meters Hack Chat” →

Sixty Years Ago Today: Yuri Gagarin Becomes The First Human In Space

April 12, 2021 by 17 Comments

As those of us with an interest in space exploration look forward with excitement towards new Lunar and Martian exploration, it’s worth casting our minds back for a moment because today marks a special anniversary. Sixty years ago on April 12th 1961, the Vostok 1 craft with its pilot Yuri Gagarin was launched from the Baikonur cosmodrome in what is now Kazakhstan. During the 108-minute mission he successfully completed an orbit of the Earth before parachuting from his craft after re-entry and landing on a farm near Engels, in the Saratov oblast to the south of Moscow.

Yuri Gagarin

In doing so he became the first human in space as well as the first to orbit the Earth, he became a hero to the Soviet and Russian people as well as the rest of the world, and scored a major victory for the Soviet space programme by beating the Americans to the prize. All the astronauts and cosmonauts who have been to space since then stand upon the shoulders of those first corps of pioneering pilots who left the atmosphere alone in their capsules, but it is Gagarin’s name that stands tallest among them.

In Russia the anniversary is being celebrated with particular fervour with special events, TV coverage, and a visit by President Putin to the landing site, and from space by the Russian cosmonauts in orbit on the ISS. Meanwhile space agencies closer to home are remaining tight-lipped, with NASA failing to mention that particular objective for ISS Expedition 65 crewmembers.

We consider that the politics of the Cold War should not be allowed to detract on our side of the world from the achievement of Gagarin and the engineers and scientists who placed him in orbit, thus we prefer to tell the whole story when dealing with space history. If you’d like to read a bit more Vostok history then we’d like to point you at the story of another Soviet cosmonaut, Valentina Tereshkova, the first woman in space.

Header image: Нина ПЕТРИЩЕВА, CC BY-SA 4.0.

MicroLEDs: Lighting The Way To A Solid OLED Competitor

April 12, 2021 by 59 Comments

We’re accustomed to seeing giant LED-powered screens in sports venues and outdoor displays. What would it take to bring this same technology into your living room? Very, very tiny LEDs. MicroLEDs.

MicroLED screens have been rumored to be around the corner for almost a decade now, which means that the time is almost right for them to actually become a reality. And certainly display technology has come a long way from the early cathode-ray tube (CRT) technology that powered the television and the home computer revolution. In the late 1990s, liquid-crystal display (LCD) technology became a feasible replacement for CRTs, offering a thin, distortion-free image with pixel-perfect image reproduction. LCDs also allowed for displays to be put in many new places, in addition to finally having that wall-mounted television.

Since that time, LCD’s flaws have become a sticking point compared to CRTs. The nice features of CRTs such as very fast response time, deep blacks and zero color shift, no matter the angle, have led to a wide variety of LCD technologies to recapture some of those features. Plasma displays seemed promising for big screens for a while, but organic light-emitting diodes (OLEDs) have taken over and still-in-development technologies like SED and FED off the table.

While OLED is very good in terms of image quality, its flaws including burn-in and uneven wear of the different organic dyes responsible for the colors. MicroLEDs hope to capitalize on OLED’s weaknesses by bringing brighter screens with no burn-in using inorganic LED technology, just very, very small.

So what does it take to scale a standard semiconductor LED down to the size of a pixel, and when can one expect to buy MicroLED displays? Let’s take a look. Continue reading “MicroLEDs: Lighting The Way To A Solid OLED Competitor” →

Exhuming An Ancient Game From A Government Warehouse

April 12, 2021 by 21 Comments

Many readers will be familiar with the final scene of Raiders Of The Lost Ark, in which the Ark of the Covenant, having been retrieved by Indiana Jones, is placed in a crate and wheeled off to be lost in the seemingly infinite depths of a dusty Government warehouse. Who knows what treasures lurk in such fabled taxpayer-funded repositories, and as if to prove their vast potential, [Arthur O’Dwyer] relates a tale of digital archaeology in which the entire source code of a game thought long-lost was regurgitated with the help of a civil servant.

The game in question is Castlequest, which he had played in the 1980s on the now-defunct GEnie online service. One of very few online references to it came via an entry in the copyright catalog of the US Copyright Office, where copyright holders can choose to register their works. Eventually after some detective work and a conversation with one of the game’s authors, he received copies of the entry. But instead of the expected summary, he was pleasantly surprised to find the full Fortran code of the game. The snag was that it came as a PDF scan of printed pages rather than as code itself, so there followed a tedious process of transcription before it could be published in a GitHub repository and eventually made compilable. The code remains copyrighted as an important part of its story, but should you be interested you can transport yourself back four decades and try your luck at text adventuring.

Maybe there’s more to be found in those dusty copyright warehouses, and searching for it has to be more pleasant than digging up landfills.

Playing The Interview Game

April 12, 2021 by 37 Comments

Technical interviews are generally dreaded, just like every other interview. However, technical interviews include many elements that non-technical folks might find mystifying or even pointless, such as whiteboard problem solving, take-home assignments, design sessions, or even just straight brain teasers. [Erik McClure] went a bit off the beaten path and started using the factory builder game Factorio as a technical interview.

Many point to the intent behind the problems and tricky questions inherent in whiteboard coding exercises and assert that the focus is not to complete the problem, but rather to expose how a candidate thinks and problem solves. Factorio is all problem-solving as you work as a team to slowly scale up a humble production line to a massive factory, which makes it a good candidate for assessing these sorts of skills. We doubt that the fine developers who wrote the game ever imagined it being used as an interview.

In all likelihood, you probably won’t have a Factorio interview anytime soon as [Erik] estimated each interview would take between eight and twenty hours. But we love the idea of reimagining the interview from a tedious set of problems to solve to an evolving cooperative game. Of course, you can also read more about getting the experience necessary for a job and what companies are looking for in an interview.

A trailer for Factorio is after the break.

Continue reading “Playing The Interview Game” →

High Current Measurement Probe For Oscilloscopes

April 11, 2021 by 22 Comments

A decent current measurement sensor ought to be an essential part of every hacker’s workbench. One that is capable of measuring DC, as well as low and high frequencies with reasonable accuracy. And bonus credits if it can also withstand high bus voltages – such as those found in mains utility or electric vehicle work. [Undersilicon] couldn’t find one that ticked all the boxes, so he built an ACS730 based AC/DC current probe capable of measuring up to 25 A at frequencies up to 1 MHz.

Allegro Microsystems has a wide offering of current sensor IC’s. The ACS730 features a -3 dB bandwidth of 1 MHz, and -1 dB bandwidth of 500 kHz. Since it is galvanically isolated, it can be used in AC mains applications up to 297 Vrms and for DC up to 420 V. And as he intended to use it as an oscilloscope accessory, the analog output suited the application nicely. A pair of precision op-amps provide the voltage output scaled to 100 mV/A. The board is powered off a 1000 mAh LiPo battery that can run the sensor for about 15 ~ 20 hours. The power supply section consists of a charge circuit for the LiPo, and a split rail dual output power supply converter for the op-amps.

The ACS730 has a 2.5 V output when measured current is zero, and is scaled for 40 mV/A. This gives an output voltage swing from -0.5 V for -50 A to +4.5 V for +50 A. This is where the AD823ARZ dual 16 MHz, Rail-to-Rail FET Input Amplifiers step in. One pair is used to obtain a 2.5 V reference from the 5 V supply, and also to buffer the analog output from the ACS730. The second pair subtracts the 2.5 V offset, and applies a gain of 2.5 to get the 100 mV/A output. Dual power supply for the op-amps comes from a TPS65133 Split-Rail Converter, ±5V, 250mA Dual Output Power Supply. Lastly, LiPo charging is handled by the MCP73831 Single Cell, Li-Ion/Li-Polymer Charge Management Controller.

Initial testing of direct currents has shown fairly accurate performance. But he’s observed some noise when measuring currents below 1 A which requires some debugging to figure out the source. [Undersilicon] has provided the CAD files for both the PCB and 3D printed enclosure, giving you access to everything you need to build one yourself. If you’re looking for something a bit more heavy duty, you might be interested in this +/-50 A, 1.5 MHz sensor encased in concrete.

LED Brightness Adjustment Uses Itself As Sensor

April 11, 2021 by 16 Comments

This is a story about a successful system that nevertheless failed to make the cut. An experimental LED brightness adjustment is something [Mitxela] explored in a project for a high-precision clock; one that shows time down to the nearest millisecond, and won’t flicker or otherwise look weird when photographed with a high-speed camera. To pull this off means reinventing many things about a clock display, including how to handle brightness adjustment elegantly. Now, to be clear, the brightness adjustment idea described here is something that did not end up being used, but it’s interesting enough that [Mitxela] wrote it up and we’re very glad he did.

The idea was to have a smooth and seamless automatic brightness adjustment, ideally with no added components. Since LEDs can be used as light sensors, [Mitxela] saw an opportunity to use elements of the clock displays themselves as sensors. This is how it works: a charge in the p-n junction that makes up an LED will decay at a rate proportional to the amount of light hitting the junction. By measuring the speed of this decay, it’s therefore possible to tell how much light is hitting the LED. It’s effective and elegant, but there are a few practical issues to deal with.

The first failed idea was to employ as sensors the unused decimal points in the seven-segment LED modules, but that turned out to have issues. One was the common-cathode wiring of the display modules; this makes them very convenient to drive as displays, but made using the decimal point as a light sensor impractical. The other issue was that the built-in diffuser that makes the displays easier to read absorbs a lot of ambient light. A much better option was to use the LEDs in the colon separators between digits, since they’re independent. Naturally they still have to light up in addition to being used as sensors, but [Mitxela] made a successful prototype by performing the necessary measurements in between the LEDs being driven by PWM.

Despite how clever and efficient the solution was, in the end what sank it was the fact that the LEDs just don’t do a very good job of sensing ambient light for this purpose. The LEDs are simply too directional. Even after sanding away the top (lens) part of the LEDs, they still had a very narrow field of view. As [Mitxela] describes it, tilting the clock towards the ceiling could send it to full brightness, and the shadow of one’s head falling across the clock would plummet it into “night mode” dimness. In short, it responded to what was directly in front of it, rather than the ambient light level as a whole.

It’s a reminder that sometimes a solution simply won’t tick all the right boxes, and it can happen for unexpected reasons. Still, LEDs are versatile things. Not only can they sense light, but as the name implies they’re also diodes. As diodes can be used as temperature sensors that means LEDs can as well.