Snooping On SIM Cards

February 2, 2016 by Elliot Williams 23 Comments

[Nils Pipenbrinck] has been working on a very interesting problem. The SIM card in your cellphone talks to the contactless near-field communication (NFC) chip through a cool protocol that we’d never hear of until reading his blog: single wire protocol (SWP).

The SIM card in your cellphone has only a limited number of physical connections — and by the time NFC technology came on the scene all but one of them was in use. But the NFC controller and the SIM need full-duplex communications. So the SWP works bi-directionally on just one wire; one device modulates the voltage on the line, while the other modulates the current, essentially by switching a load in and out.

This signalling protocol makes snooping on this data line tricky. So to start off his explorations with SWP, [Nils] built his own transceiver. That lead [Nils] to some very sensitive analog sniffer circuit design that he’s just come up with.

If you get interested in SWP, you’ll find the slides from this fantastic presentation (PDF) helpful, and they propose a solution very similar to the one that [Nils] ended up implementing. That’s not taking anything away from [Nils]’s amazing work: with tricky high-speed analog circuitry like this, the implementation can be more than half of the battle! And we’ll surely be following [Nils]’s blog to see where he takes this.

Banner image: An old version and a new version of the transceiver prototype.

Thanks to [Tim Riemann] for the tip!

New Research Sheds Light On 3D Printing Fumes

February 1, 2016 by Elliot Williams 28 Comments

A few years back, there were some studies on the chemical and particle emissions coming out of the hotends of 3D printers. Although they galvanized a lot of people in the community, the science wasn’t entirely conclusive — one paper made it sound like you needed a hazmat suit for 3D printing, and the other suggested that cooking a meal in a kitchen was worse for you. That’s because they were measuring different things.

This new research paper on the emissions of 3D printers covers all the bases. They examined a variety of different materials printed in different printers. They also measured both chemical emissions and Ultrafine Particles (UFP) which can be hazardous even when the material itself is not.

We read the paper (PDF) so that you don’t have to. Here’s our takeaways:

There was no significant variation across brands of 3D printers. (Duh?)
ABS and similar materials outgas styrene at levels you should probably be worrying about if you’re running your printer for a few hours a day in an unventilated office.
PLA emitted significantly less overall, and most of it was a non-hazardous chemical, lactide. PLA doesn’t look like a problem.
All of the materials resulted in increased UFP exposure. These levels are above normal household background levels, but lower than certain “microclimates” which (if you follow the references) include principals’ offices with carpet, automobiles, restaurants, and rooms with burning candles or running hair dryers. In short, the UFP exposure doesn’t look like it’s going to be a big deal unless you’re sitting right next to the printer and running it continually.

So what would we do? It now looks like it’s prudent to print ABS only in a well-ventilated room. Or enclose the printer in a box and vent whatever you can outside — which can also help prevent breezes cooling the piece down unevenly and adding to ABS’s warping problems. Or just stick to PLA. It looks essentially harmless.

Thanks [Jim Scheitel] for the tip!

Hacking The Internet Of Things: Decoding LoRa

January 31, 2016 by Elliot Williams 20 Comments

Getting software-defined radio (SDR) tools into the hands of the community has been great for the development and decoding of previously-cryptic, if not encrypted, radio signals the world over. As soon as there’s a new protocol or modulation method, it’s in everyone’s sights. A lot of people have been working on LoRa, and [bertrik] at RevSpace in The Hague has done some work of his own, and put together an amazing summary of the state of the art.

LoRa is a new(ish) modulation scheme for low-power radios. It’s patented, so there’s some information about it available. But it’s also proprietary, meaning that you need a license to produce a radio that uses the encoding. In keeping with today’s buzzwords, LoRa is marketed as a wide area network for the internet of things. HopeRF makes a LoRa module that’s fairly affordable, and naturally [bertrik] has already written an Arduino library for using it.

So with a LoRa radio in hand, and a $15 RTL-SDR dongle connected to a laptop, [bertrik] got some captures, converted the FM-modulated chirps down to audio, and did a bunch of hand analysis. He confirmed that an existing plugins for sdrangelove did (mostly) what they should, and he wrote it all up, complete with a fantastic set of links.

There’s more work to be done, so if you’re interested in hacking on LoRa, or just having a look under the hood of this new modulation scheme, you’ve now got a great starting place.

Pacman Proves Due Is More Than Uno

January 30, 2016 by Elliot Williams 28 Comments

If you’re wondering what the difference is between the good ol’ Arduino Uno and one of the new-school Arduinos like the Arduino Due, here’s a very graphic example: [DrNCX] has written a stunning Pacman clone for the Due that seems to play just like the arcade. (Video embedded below the break.)

The comparison between the Uno and Due isn’t quite fair. The Due runs on an 84 MHz, 32 bit ARM Cortex-M3 processor. It’s in a different league from the Uno. Still, we view this as an example of the extended possibilities from stepping up into a significantly faster micro. For instance, the video is output to both an ILI9341 TFT screen and external 8-bit VGA at once.

Besides using some very nice (standard) libraries for the parts, it doesn’t look like [DrNCX] had to resort to any particular trickery — just a lot of gamer-logic coding. All the code is up on GitHub for you to check out.

Can the old Arduinos do this? For comparison, the best Pacman we’ve seen on an AVR platform is the ATmega328-based RetroWiz, although it is clocked twice as fast as a stock Uno. And then there’s Hackaday Editor [Mike Szczys]’s 1-Pixel Pacman, but that’s cheating because it uses a Teensy 3.1, which is another fast ARM chip. People always ask where the boundary between an 8-bit and 32-bit project lies. Is a decent Pacman the litmus test?

Continue reading “Pacman Proves Due Is More Than Uno” →

ESP8266 Killer?

January 30, 2016 by Elliot Williams 47 Comments

We’ve seen rumors floating around the Twittersphere about a new integrated microprocessor and WiFi SOC: the NL6621 from Nufront. Details are still scarce, but that doesn’t seem to be because the chip is vaporware: you could buy modules on Taobao.com and eBay right now for between two-and-a-half and three bucks, and Nufront’s website says they’ve produced a million modules since 2013.

The NL6621 WiFi SOC is powered by a 160 MHz ARM Cortex-M3 with 448 KB of RAM, and everything else is integrated in the SOC. The module has 32 GPIOs, SPI, I2C, I2S digital audio, and most of the peripherals that you’d expect. They say they have a completely open source SDK, but we can’t find a link to it anywhere. An English-language forum has sprung up in anticipation of the next new thing, and they say that they’ve contacted Nufront about the SDK, so that’s probably as good a place as any to lurk around if you’re interested. With an ARM core, it shouldn’t be long before someone gets GCC working on these things anyway.

It’s also worth noting that we’ve announced ESP8266 killers before, and it hasn’t come to pass. The mixture of community and official support that (eventually) came out of Espressif seems to be the main factor determining the ESP8266’s success, and we don’t see that yet with the NL6621. So take the question mark in the title seriously, but if this turns out to be the next big thing, remember where you heard it first, ok?

Thanks [David Hunt] for the tip!

Hack Mobile With A Bus Pirate GUI For Your Phone

January 30, 2016 by Elliot Williams 8 Comments

You need to get an SPI bus on something right now, but you left your laptop at home. No problems, because you’ve got your Bus Pirate and cellphone in your pocket. And a USB OTG cable, because you’re going to need one of those. And some probes. And maybe a soldering iron for tacking magnet wire onto those really small traces. And maybe a good magnifying glass. And…

OK, our fantasy of stepping away from the party for a quick JTAG debugging session is absurd, but what’s not at all absurd is the idea of driving your Bus Pirate from a nice GUI app on your Android phone. [James Newton] wrote DroidScriptBusPirate so that he wouldn’t have to hassle with the Bus Pirate’s nested single-character menu system, and could easily save complete scripts to do common jobs from pleasant menus on his phone.

The setup depends on downloading DroidScript, a free Javascript and HTML5 IDE, and then pasting and saving [James]’ code. He’s written up full instructions to help you with the install. It’s not so hard, and once you’re done you’ll be ready to drive the Pirate from the comfort of your phone.

In fact, now that we think of it, we’re missing a Bus Pirate GUI for our desktop as well. Whenever we have complex tasks, we end up scripting something in Python, but there ought to be something more user-friendly. Anyone know of a good GUI solution?

Most Beautiful Mini-Galaga-Pi Ever!

January 30, 2016 by Elliot Williams 21 Comments

The problem with click-bait titles, besides the fact that they make the reader feel cheated and maybe a little bit dirty for reading the article, is that they leave us with nothing to say when something is truly outstanding. But the video of [Tiburcio de la Carcova] building up a mini-Galaga cabinet (complete with actual tiny CRT screen from an old portable 5″ TV) is actually the best we’ve ever seen.

Plywood is laser-cut. Custom 3D printed parts are manufactured and assembled, including the joysticks and coin door. Aluminum panels are cut on a bandsaw and bent with a hand brake. Parts are super-glued. In short, it’s a complete, sped-up video of the cutting-edge of modern DIY fab. If that’s not enough reason to spend four minutes of your time, we don’t know what is.

[Tiburcio] has also made a mini Space Invaders, and is thinking of completing the top-20 of his youth. Pacman, Asteroids, and Missile Command are next. We can’t wait.

There are (ahem) a couple of Raspberry-Pi-powered video game emulators on Hackaday, so it’s a little awkward to pick one or two to link in. We’ll leave you with this build that also uses a small CRT monitor to good effect albeit in less-fancy clothing.

Continue reading “Most Beautiful Mini-Galaga-Pi Ever!” →