Plaster casts are blank canvases for friends and family to post their get well messages. But if it’s holiday season, adding blinky LED lights to them is called for. When [Dr Lucy Rogers] hurt her hand, she put a twitter enabled LED Christmas tree on her cast.
The hardware is plain simple – some RGB LEDs, an Arduino, a blue tooth module and a battery. The LEDs and wires formed the tree, and all the parts were attached to the plaster cast using Velcro. This allowed the electronics to be removed during future X-ray scans. The fun part was in connecting the LEDs to the #CheerLights project. CheerLights is an “Internet of Things” project that allows people’s lights all across the world to synchronize to one color set by a Tweet. To program the Arduino, she used code written by [James Macfarlane] which allowed the LED color to be set to any Cheerlights color seen in blue tooth UART data.
Connectivity is coordinated using MQTT — lightweight standard popular with connected devices. By connecting the MQTT feed to the cheerlights topic from [Andy Stanford-Clark’s] MQTT feed (mqtt://iot.eclipse.org with the topic cheerlights) the lights respond to tweets (Tweet #cheerlights and a color). The LED colors can also be selected via the phone from the color picker tool in the controller, or directly via the UART. If the Bluetooth connection is lost, the LEDs change colors randomly. Obviously, delegates had great fun when she brought her Twitter enabled LED blinky lights plaster cast arm to a conference. It’s not as fun unless you share your accomplishments with others!
[Daniel Lange] and [Felix Domke] gave a great talk about the Volkswagen emissions scandal at this year’s Chaos Communication Congress (32C3). [Lange] previously worked as Chief architect of process chain electronics for BMW, so he certainly knows the car industry, and [Domke] did a superb job reverse-engineering his own VW car. Combining these two in one talk definitely helps clear some of the smog around the VW affair.
[Lange]’s portion of the talk basically concerns the competitive and regulatory environments that could have influenced the decisions behind the folks at VW who made the wrong choices. [Lange] demonstrates how “cheating” Europe’s lax testing regime is fairly widespread, mostly because the tests don’t mimic real driving conditions. But we’re not sure who’s to blame here. If the tests better reflected reality, gaming the tests would be the same as improving emissions in the real world.
As interesting as the politics is, we’re here for the technical details, and the reverse-engineering portion of the talk begins around 40 minutes in but you’ll definitely want to hear [Lange]’s summary of the engine control unit (ECU) starting around the 38 minute mark.
[Domke] starts off with a recurring theme in our lives, and the 32C3 talks: when you want to reverse-engineer some hardware, you don’t just pull the ECU out of your own car — you go buy another one for cheap online! [Domke] then plugged the ECU up to a 12V power supply on his bench, hooked it up, presumably to JTAG, and found a bug in the firmware that enabled him to dump the entire 2MB of flash ROM into a disassembler. Respect! His discussion of how the ECU works is a must. (Did you know that the ECU reports a constant 780 RPM on the tacho when the engine’s idling, regardless of the actual engine speed? [Domke] has proof in the reverse-engineered code!)
The ECU basically takes in data from all of the car’s sensors, and based on a number of fixed data parameters that physically model the engine, decides on outputs for all of the car’s controls. Different car manufacturers don’t have to re-write the ECU code, but simply change the engine model. So [Domke] took off digging through the engine model’s data.
Long story short, the driving parameters that trigger an emissions reduction exactly match those that result from the EU’s standardized driving schedule that they use during testing — they’re gaming the emissions tests something fierce. You’ve really got to watch the presentation, though. It’s great, and we just scratched the surface.
“What’s the weather like, honey?” “I don’t know. Let me check the mirror.” The mirror?
Both [Dylan Pierce] and [squix] have mirror projects that display the weather. They took two different approaches which makes for an interesting comparison. [Dylan] uses a Raspberry Pi with an actual monitor behind the mirror. [squix] puts an OLED behind the mirror driven by a ESP8266. It appears there is more than one way to hack a mirror, or anything, which is what makes hacking fun.
Raspberry Pi Booting
Framing Mirror and Monitor
[squix] started with a picture frame, adding tinting film to the glass so it would reflect. A small section of tint was removed to allow the OLED to be seen. The ESP8266 software connects to the Weather Underground to get the latest information.
The Raspberry Pi version by [Dylan] puts a 27″ monitor behind the mirror. That is either terribly impressive or way over the top but seeing Linux boot behind the mirror makes it worth the effort. The Pi generates a web page which makes this adaptable as a general purpose kiosk.
A video of [squix]’s mirror in operation, after the break.
The yuletide fire is out, so we’re starting to receive this year’s Christmas hacks. [Chris] sent us his awesome video-mapped tree lighting hack. His project made clever use of a bunch of cool tools, so even if you’re not thinking forward to next December, it’s worth a look. Still images don’t do it justice; check out the video below the break.
The end result is an addressable string of WS2812B LEDs connected up to a Raspberry Pi Zero that can display a video image even though it’s wrapped around a roughly cone-shaped (pine) object. But this is actually more impressive than you’d think at first; how would you map a flat image to a string of LEDs wrapped around a tree?
[Chris]’s solution was to write a routine that lit up the LEDs in a unique pattern and then detected them using OpenCV and a webcam, making the mapping directly. He then samples images from a video at exactly the points where the pixels are located on the tree, and sends this data out to the LEDs.
The basic framework here should transform fairly easily into a generic image-mapping procedure with randomly located LEDs, so we think it’s a hack that’ll outlast the season. And because it runs on the Pi Zero, everything is in Python so it’d be a good project for beginners to replicate. However, the code section on the project page still lists it as coming soon. We hope so!
The Raspberry Pi Zero was back in stock at Adafruit this week – for about eight minutes. That means a few more people get Pi Zeros, many more will put them up on eBay, and everyone is working on their own version of a Pi Zero USB hub. The latest version of a Pi Zero hub comes from [Nate], and he’s doing this one right. His Pi USB adapter adds four USB ports and features not found in other DIY USB hubs like fuses and ESD protection.
As with other Pi Zero USB hub add-ons, this build relies on a USB hub controller, a few passives, and not much else. The chip used in this hub is the FE1.1s chip, a highly integrated 4-port hub controller that can be found through the usual Chinese resellers. This hub controller doesn’t require much, just a 12MHz crystal, a few passives, and four USB jacks.
Of particular interest is how [Nate] is connecting this hub to the Pi Zero. He’s left the option open for using either a USB cable, or soldering the USB’s differential pairs directly between the Pi and the hub. In either case, the hub should work, and with the addition of the zeners, fuses, and other parts that keep the hub from frying itself, [Nate] might have a very nice project on his hands.
North Korea is a surveillance state propped up by a totalitarian government infamous for human rights abuses and a huge military that serves the elite while the poor are left to fight over scraps. Coincidently, that’s exactly what North Korea says about the United States.
There is one significant difference between the two countries: North Korea has developed its own operating system for its citizens, called Red Star OS. It’s an operating system based on Linux, but that has a few interesting features that allow Glorious Leader to take care of his citizens. A deep teardown of what has gone into the development of Red Star OS hasn’t been available until now, with [Florian Grunow] and [Niklaus Schiess]’s talk at the Chaos Communication Congress this week.
Kim Jong-Un with an iMac
The first question anyone must ask when confronted with an operating system built by a country that doesn’t have much electricity is, “why?” This question can only be answered philosophically; the late Kim Jong-Il stressed the importance of North Korea developing “their own style” of programming, and not relying on western operating systems. Nearly everything in Red Star has been modified, with a custom browser called Naenara, a crypto tool, a clone of Open Office, a software manager, and a custom music composition tool. Red Star also had to have the look and feel of OS X; that is, after all, what Glorious Leader uses.
Red Star goes much deeper than custom browsers and a desktop theme. There are other, subtler components inside the OS. There is a program that verifies the integrity of the system by checking signatures of the custom files against a database. If a file has been tampered with, the system reboots. Since this tamper check runs on bootup, Red Star makes it nearly impossible to modify files for study. This is one of the big features designed into Red Star – system integrity is paramount.
There are other custom bits of software that hide files from the user even if they have root, and a ‘virus scanner’ that is anything but. This virus scanner checks documents for patterns that, when put through Google Translate, are strange, weird, and somewhat understandable. Phrases like, “punishment”, “hungry”, and “strike with fists” are detected in all documents, and depending on what the developers decide, these documents can be deleted on a whim.
While scanning a system for documents that contain non-approved speech is abhorrent enough, there’s another feature that would make any privacy advocate weep. Media files including DOCX, JPG, PNG, and AVI files are watermarked by every computer that opened the files. This allows anyone to track the origin of a file, with the obvious consequences to free speech that entails.
While most people in the US consider North Korea to be a technological backwater and oppressive regime, the features that make Red Star OS useful to the DPRK are impressive. The developers touched nearly everything in Red Star, and the features inside it are rather clever and make their style of surveillance very useful. They’re also doing this without any apparent backdoors or other spycraft; they’re putting all their surveillance out in the open for all to see, which is, perhaps, the best way to go about it.
Hobbyist 3D printers have had a home in the maker space for years now. Along the way, they’ve left a mark in our imaginations. They’ve tickled our fancy for watching a computer orchestrated symphony written in G-code hum away while cranking out parts. They’ve opened a door to the idea that while computer controlled machines may be decades old, having one or two homebrew setups in our garage might not be as far-fetched as we first thought. Now that we’ve seen the steppers and linear slides that go into these setups, it’s not unreasonable for many of us to start asking: What else? Perhaps a computer numerically controlled (CNC) lathe, mill, or even a laser cutter–anything that would add to the vocabulary of tools and techniques that we’re starting to build at home.
VSlot linear rail system for building multiaxis linear actuator systems
Since 3D printers have become somewhat commonplace, it’s not too difficult to find commodity spare parts spilling to the surface of online vendors’ websites. We can even find kit versions for building our own variants. Now that the notion of CNC-at-home is here to stay, the question for 2016 is: do we build our own CNC tools or buy them?
Despite the countless CNC build logs, extruded aluminum kits, and open source G-code interpreters, I’m still convinced that unless your needs are truly custom, buying the machine that fits your needs will have you putting together projects faster and with far less maintenance than you’d need if you assembled the machine yourself. In what follows, I thought I’d explore a few machines that we can find today in 2016 that make the dream of desktop fabrication a reality.
