Speaking CAN With Open Source Hardware

You can buy a dongle with a weird industrial connector that fits under the dash of any car on the road for $15. This is just a simple ODB-II transceiver meant for reading error codes and turning a Crown Vic into a police interceptor. There’s a lot more to the CAN Bus than OBD-II; robots and industrial control units, for instance, and Hackaday alum [Eric] has developed an open source tool for all things CAN.

[Eric] built this tool because of a lac of open-source tools that can talk CAN. There are plenty of boards floating around that can reset codes in a car using OBD-II, but an open hardware CAN device doesn’t really exist.

The CANtact is a small board outfitted with a USB port on one end, a DE-9 port on the other, and enough electronics to talk to any CAN device. The hardware on the CANtact is an STM32F0 – an ARM Cortex M0 that comes with USB and CAN interfaces. This chip connects to a Microchip CAN transceiver, and that’s pretty much all you need to talk to cars and industrial automation equipment. If doing something legal, moral, or safe with the CAN bus in your car isn’t your thing, Wired reports you can digitally cut someone’s brake lines.

On the software side of things, the CANtact can interface with Wireshark and the CANard Python library. All the files, from hardware to software, are available on the Github. Oh, CANtact was at Black Hat Asia, which means [Eric] was at Black Hat Asia. We should have sent stickers with him.

19 thoughts on “Speaking CAN With Open Source Hardware

  1. There a plenty of open source CAN boards out there (and have even been featured here.) CANBus Triple is a recent one with Bluetooth: https://www.canb.us. Another is http://goodfet.sourceforge.net/hardware/goodthopter12/. However, I do like the CANtact’s jumper selectable DB9 pins. I just wish one of these boards would include a Single-Wire CAN transceiver in addition to the normal CAN transceiver, and make Single-Wire mode selectable with a jumper, as well.

  2. “ODB-II transceiver meant for reading error codes and turning a Crown Vic into a police interceptor.”

    ??? How does a ODB-II transceiver turn a Crown Vic into a police interceptor? I bet city governments will be really mad when they learn that they can convert ordinary cars into police interceptors for $15. Where can I buy one? Will it work with other models?

    1. There is more to the police cruiser variants of certain cars than just performance modifications, so no, it’s not really a matter of just buying this device. Those generally have heavier duty braking components, stiffer suspensions (to be able to get the power to the ground properly), and other features that most folks don’t see that make the police variants cost more.

      1. It’s got a cop motor, a 440 cubic inch plant, it’s got cop tires, cop suspensions, cop shocks. It’s a model made before catalytic converters so it’ll run good on regular gas.

          1. “It’s 106 miles to Chicago, we have a full tank of gas, half a packet of cigarettes, it’s dark and we’re wearing sunglasses… HIT IT!” RIP Jake. It was funny in 1980 and it’s still funny today, thanks for the laff!

  3. Im most interested in CAN for ‘hacking’ the comms between DJI modules in multi rotors.
    Apparently you can sniff all the flight parameters including accelerometer / gyro / GPS data.
    Excellent for implementing an auto pilot.

    Anyone know the best kit to get for this?

  4. This article and the comments that go with it led me to a few devices for CAN to USB, which can be helpful in my everyday work (working with PLCs and such). I’m the only one at the office using a PCAN-USB from Peak but would love to introduce my coworkers to CAN bus and of course, use opensource devices instead of some dark closed device with closed software. Thank you everyone!

  5. I’m working on an adapter board for teensy that has GPS/GSM, nano sim, a CAN tx and a digital switch for CAN L1/H1 L2H2 (some cars have 3 or more data lines at the OBD connector), all on a board the same size as teensy 3.1.
    Should be lots of fun when its ready.

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