Teensey and Vehicle CAN

[nickweb]

Silly question. Almost a newbie at electronics. As the teensey has CAN hardware on board, can I use it to read vehicle data from the OBDII port direct or will extra hardware be required?

Thanks for any guidance!
Nick

[ohhorob]

Googling for "teensy can" gives this as the first result .. https://github.com/teachop/FlexCAN_Library

That mentions hardware requirements..

[nickweb]

Googling for "teensy can" gives this as the first result .. https://github.com/teachop/FlexCAN_Library

That mentions hardware requirements..

You're right. It does. It doesn't mention anything about Vehicle CAN bus systems via OBDII ports however.

Unless I've missed something in the readme file?

[ohhorob]

These should be wired to a 3.3V CAN transceiver...

and then later .. https://github.com/teachop/FlexCAN_L...ceiver-options

Please add parts you are using successfully with Teensy 3.1 to this list.

TI SN65HVD230D on 3.3V (1MBPS)
TI SN65HVD232D / SN65HVD232QDQ1 on 3.3V (1MBPS)
NXP TJA1050T/VM,118 on the same 5V supply as the Teensy. (1MBPS)
Microchip MCP2551 on 5V (reported at 500KBPS)
Linear LT1796 on 5V (not speedtested)

And I see a bunch of OBDII specific bits at sparkfun.. https://www.sparkfun.com/search/results?term=obdII

[PaulStoffregen]

You must use one of those CAN transceiver chips. The output pins on those chips are meant to be able to connect to a CAN bus, like the ones in your vehicle. Don't forget the ground connection, which is implied but not always explicitly shown in wiring diagrams.

Teensy requires 5V power to run. If powering in a vehicle, you'll probably need a 12V to 5V power supply. Beware, cars can have terribly noisy 12V systems, especially if the car's battery becomes disconnected while the engine is running. Many power supplies not designed for automotive use might not survive those scenarios. Some might even pass the noise onto Teensy, possibly destroying it as well.