Day: December 31, 2015

Break Your Wrist? Twitter-Enable That Plaster Cast

December 31, 2015 by 1 Comment

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!

32C3: Dieselgate — Inside The VW’s ECU

December 31, 2015 by 67 Comments

[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.

And if you’re interested in our other coverage of the Congress, we have quite a collection going already.