can-bus

53 Articles

Reverse Engineering The Smart ForTwo CAN Bus

February 28, 2017 by 33 Comments

The CAN bus has become a defacto standard in modern cars. Just about everything electronic in a car these days talks over this bus, which makes it fertile ground for aspiring hackers. [Daniel Velazquez] is striking out in this area, attempting to decode the messages on the CAN bus of his Smart ForTwo.

[Daniel] has had some pitfalls – first attempts with a Beaglebone Black were somewhat successful in reading messages, but led to strange activity of the car and indicators. This is par for the course in any hack that wires into an existing system – there’s a high chance of disrupting what’s going on leading to unintended consequences.

Further work using an Arduino with the MCP_CAN library netted [Daniel] better results, but  it would be great to understand precisely why the BeagleBone was causing a disturbance to the bus. Safety is highly important when you’re hacking on a speeding one-ton metal death cart, so it pays to double and triple check everything you’re doing.

Thus far, [Daniel] is part way through documenting the messages on the bus, finding registers that cover the ignition and turn signals, among others. Share your CAN hacking tips in the comments. For those interested in more on the CAN bus, check out [Eric]’s great primer on CAN hacking – and keep those car hacking projects flowing to the tip line!

Raspberry Pi Adds A Digital Dash To Your Car

September 28, 2016 by 37 Comments

Looking for a way to make your older car more hi-tech? Why not add a fancy digital display? This hack from [Greg Matthews] does just that, using a Raspberry Pi, a OBD-II Consult reader and an LCD screen to create a digital dash that can run alongside (or in front of ) your old-school analog dials.

[Greg’s] hack uses a Raspberry Pi Foundation display, which includes a touch screen, so you don’t need a mouse or other controls. Node.js displays the speed, RPM, and engine temperature (check engine lights and other warnings are planned additions) through a webpage displayed using Chromium. The Node page is pulling info from another program on the Pi which monitors the CAN Consult bus. It would be interesting to adapt this to use with more futuristic displays, maybe something like a pico projector and a 1-way mirror for a heads-up display.

To power the system [Greg] is using a Mausberry power supply which draws power from your car battery, but which also cleanly shuts down the Pi when the ignition is turned off so it won’t drain your battery. When you throw in an eBay sourced OBD-II Consult reader and the Consult Dash software that [Greg] wrote to interpret and display the data from the OBD-II Consult bus, you get a decent digital dash display. Sure, it isn’t a Tesla touchscreen, but at $170, it’s a lot cheaper. Spend more and you can easily move that 60″ from your livingroom out to your hoopty and still use a Raspberry Pi.

What kind of extras would you build into this system? Gamification of your speed? Long-term fuel averaging? Let us know in the comments.

UPDATE – This post originally listed this hack as working from the OBD-II bus. However, this car does not have OBD-II, but instead uses Consult, an older data bus used by Nissan. Apologies for any confusion!

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Shower Thoughts In Your Car

May 24, 2016 by 11 Comments

The subreddit for Shower Thoughts offers wisdom ranging from the profound to the mundane. For example: “Every time you cut a corner you make two more.” Apparently, [Harin] has a bit of an addiction to the subreddit. He’s been sniffing the CAN bus on his 2012 Hyundai Genesis and decided to display the top Shower Thought on his radio screen.

To manage the feat he used both a Raspberry Pi and an Arduino. Both devices had a MCP2515 to interface with two different CAN busses (one for the LCD display and the other for control messages which carries a lot of traffic.

The code is available on GitHub. There’s still work to do to make the message scroll, for example. [Harin] has other posts about sniffing the bus, like this one.

We’ve covered CAN bus quite a bit, including some non-automotive uses. We’ve even seen the CAN bus for model railroading.

Open Source OBD-II Adapter

March 27, 2016 by 55 Comments

Automotive diagnostics have come a long way since the “idiot lights” of the 1980s. The current version of the on-board diagnostics (OBD) protocol provides real time data as well as fault diagnostics, thanks to the numerous sensors connected to the data network in the modern vehicle. While the hardware interface is fairly standardized now, manufacturers use one of several different standards to encode the data. [Alex Sidorenko] has built an open source OBD-II Adapter which provides a serial interface using the ELM327 command set and supports all OBD-II standards.

The hardware is built around the LPC1517 Cortex-M3 microprocessor and can accept a couple of different versions. Here’s the PDF schematic, and a set of Gerber files (ZIP archive) for the PCB layout, if you’d like to dig in to it’s internals. The MC33660 ISO K Line Serial Link Interface device is used to provide bi-directional half-duplex communication interface with the micro-controller. Also included is the TJF1051, a high-speed CAN transceiver that provides an interface between the micro controller and the physical two-wire CAN lines on the ODB-II connector. The serial output from the adapter board is connected to a computer using a serial to USB adapter.

The software is written in C++ for the LPCXpresso IDE – a GNU tool chain for ARM Cortex-M processors, but can also be compiled using a couple of other toolchains. He’s got instructions if you’d like to build the firmware from source, or if you’d like to program the adapter via Flash Magic.

We featured [Alex]’s inexpensive PIC based ODB-II interface way back in 2007, so he’s been working on this for a while and has a good grip on what he’s doing.

car dashboard

How Those Hackers Took Complete Control Of That Jeep

August 22, 2015 by 72 Comments

It was an overcast day with temperatures in the mid seventies – a perfect day to take your brand new Jeep Cherokee for a nice relaxing drive. You and your partner buckle in and find yourselves merging onto the freeway just a few minutes later.  You take in the new car smell as your partner fiddles with the central touch screen display.

“See if it has XM radio,” you ask as you play with the headlight controls.

Seconds later, a Taylor Swift song begins to play. You both sing along as the windows come down. “Life doesn’t get much better than this,” you think. Unfortunately, the fun would be short lived. It started with the windshield wipers coming on – the dry rubber-on-glass making a horrible screeching sound.

“Hey, what are you doing!”

“I didn’t do it….”

You verify the windshield wiper switch is in the OFF position. You switch it on and off a few times, but it has no effect. All of the sudden, the radio shuts off. An image of a skull and wrenches logo appears on the touchscreen. Rick Astley’s “Never Gonna Give You Up” begins blaring out of the speakers, and the four doors lock in perfect synchronization. The AC fans come on at max settings while at the same time, you feel the seat getting warmer as they too are set to max. The engine shuts off and the vehicle shifts into neutral. You hit the gas pedal, but nothing happens. Your brand new Jeep rolls to a halt on the side of the freeway, completely out of your control.

Sound like something out of a Hollywood movie? Think again.

[Charlie Miller], a security engineer for Twitter and [Chris Valasek], director for vehicle safety research at IOActive, were able to hack into a 2014 Jeep Cherokee via its wireless on-board entertainment system from their basement. A feature called UConnect, which allows the vehicle to connect to the internet via a cellular connection, has one of those things you might have heard of before – an IP address. Once the two hackers had this address, they had the ‘digital keys’ to the Jeep. From there, [Charlie] and [Chris] began to tinker with the various firmwares until they were able to gain access to the vehicle’s CAN bus. This gives them the ability to control many of the car’s functions, including (under the right conditions) the ability to kill the brakes and turn the steering wheel. You probably already have heard about the huge recall Chrysler issued in response to this vulnerability.

But up until this weekend we didn’t know exactly how it was done. [Charlie] and [Chris] documented their exploit in a 90 page white paper (PDF) and spoke at length during their DEF CON talk in Las Vegas. That video was just published last night and is embedded below. Take look and you’ll realize how much work they did to make all this happen. Pretty amazing.

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Instrument Cluster Clock Gets The Show On The Road

July 3, 2015 by 24 Comments

While driving around one day, [Esko] noticed that the numbers and dials on a speedometer would be a pretty great medium for a clock build. This was his first project using a microcontroller, and with no time to lose he got his hands on the instrument cluster from a Fiat and used it to make a very unique timepiece.

The instrument cluster he chose was from a diesel Fiat Stilo, which [Esko] chose because the tachometer on the diesel version suited his timekeeping needs almost exactly. The speedometer measures almost all the way to 240 kph which works well for a 24-hour clock too. With the major part sourced, he found an Arduino clone and hit the road (figuratively speaking). A major focus of this project was getting the CAN bus signals sorted out. It helped that the Arduino clone he found had this functionality built-in (and ended up being cheaper than a real Arduino and shield) but he still had quite a bit of difficulty figuring out all of the signals.

In the end he got everything working, using a built-in servo motor in the cluster to make a “ticking” sound for seconds, and using the fuel gauge to keep track of the minutes. [Esko] also donated it to a local car museum when he finished so that others can enjoy this unique timepiece. Be sure to check out the video below to see this clock in action, and if you’re looking for other uses for instrument clusters that you might have lying around, be sure to check out this cluster used for video games.

The mechanics in dashboards are awesome, and produced at scale. That’s why our own [Adam Fabio] is able to get a hold of that type of hardware for his Analog Gauge Stepper kit. He simply adds a 3D printed needle, and a PCB to make interfacing easy.

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A Real Dash For A Truck Simulator

June 18, 2015 by 10 Comments

[Leon] plays Euro Truck Simulator 2, and like any good simulator, there are people out there building consoles, cockpits, and dashboards. In [Leon]’s case, he wanted a dashboard for his virtual trucks and cobbled one together out of a dash taken from a VW Polo.

This project was inspired by [Silas Parker] and his Arduino-based dashboard made out of a cardboard box, some servos, and a few LEDs. It worked, but [Leon] realized just about every dashboard made in the last decade or so has a CAN bus. You can just buy a CAN bus shield for an Arduino, and a dashboard can be easily found at any junkyard.

Right now, [Leon] is in the process of finding the CAN bus addresses of the relavent dials and LEDs on the dashboard. He found the tachometer at 0x280, and a bunch of indicator lights can be found at 0x470. Combined with a standard computer steering wheel and the telemetry SDK for Euro Truck Simulator 2, [Leon] has the beginnings of a virtual big rig on his desk.