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OBDII hacking

Discussion in 'Roadster: Technical' started by gregd, Nov 21, 2016.

  1. gregd

    gregd Active Member

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    So, T-Mobile (and probably others) are offering a Wi-Fi Hotspot that runs from a car's ODBII port. Called a "SyncUP Drive". Besides the hotspot, it also monitors the ODBII stuff and connects to an app for reporting on what the car's engine is up to. They had one on some sort of special deal yesterday (like, just about free), so I got it.

    The thought was to use just the hotspot part of the product features, since I know the Roadster doesn't do much talking on that port. It appears to work, but only for a few minutes, then shuts down. I'm guessing it thinks the engine is not running. I don't have the app loaded (phone is out of space), but the web browser interface to the device doesn't seem to have any knobs to adjust anything other than the network parameters (wi-fi, firewall, router, etc.).

    Is there a relatively easy way to create a fake "engine running" signal on that bus? Maybe with the new OVMS v3 (vague recollection of a pass-through port), or even a module on a Raspberry Pi? The module is nice in that it comes with lots of free data, and automatically powers up with the car (unlike a puck-style hotspot that needs to be managed).
     
  2. ecarfan

    ecarfan Well-Known Member

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    Sounds like you are referring to this product T-Mobile SyncUp Drive | Monitor Your Car & Loved Ones via Your Mobile

    Looks interesting. Sorry I can't assist you with making it work in your Roadster. I think you are likely correct that since the Roadster doesn't do much with the ODBII port the device isn't seeing the data it is designed for and so it turns off.
     
  3. gregd

    gregd Active Member

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    Yes, that's the product.

    I went for a drive in the ICE this morning, and confirmed it keeps the Wi-Fi hotspot running while the car is actually running (so it's not a defective unit). So I need to do some research and figure out how to fake enough of the stimulus to convince it that the "engine" is running.

    Would this be a good (and reasonable) follow-on to the OVMS v3, to translate what it sees from the Roadster side, and re-create it in "ICE terms" on a downlink port?
     
  4. supersnoop

    supersnoop Tesla Roadster #334

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    Does it read from the CAN bus? I would think you could just pull some wires from the diag port for that information. Or create some sort of diag->OBD2 adapter to power the device.
     
  5. gregd

    gregd Active Member

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    #5 gregd, Nov 21, 2016
    Last edited: Nov 21, 2016
    Interesting suggestion. Power isn't the problem - I was assuming, correctly, that the unit will power up and run with only the 12v from the port. But it needs some additional stimulus to keep from shutting down.

    If I can simply pull the CAN info from the other port with only wires (no active translation), that would be great (and probably unrealistic). Sounds like I need to make a break-out cable to watch what's going on. Grazing Wikipedia now...

    Probably naive question: What would happen if I plugged the dongle into the port on the passenger side? Bad idea? EDIT: Never mind; different connector.
     
  6. supersnoop

    supersnoop Tesla Roadster #334

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  7. markwj

    markwj Moderator, Asia Pacific

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    That is the plan for OVMS v3. To have an option to act like a standard OBDII controller to allow third party OBDII devices (like HUDs) to interface. It is not high up on the list, but it is there.
     

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