Page 2 of 2 FirstFirst 12
Results 11 to 18 of 18

Thread: Onstar GMLan & CAN bus GPS hacking

  1. #11
    Low Bitrate
    Join Date
    Dec 2009
    Posts
    78
    Page 47 of the datasheet describes a user-definable setting. I'll take a crack at it later on and see how close I can get it to 33.3kbps. It appears to be possible.

    Protocol B (USER1) baud rate divisor. See PP 2B for a description.

    CAN baud rate divisor. 01 to 40 02 R
    (250 Kbps)
    The protocol A CAN baud rate is determined by this value (rate in
    kbps = 500/value). For example, setting this PP to 19 (ie. decimal
    25) provides a baud rate of 500/25 = 20 kbps.

  2. #12
    VENDOR - ScanTool Vitaliy's Avatar
    Join Date
    Dec 2006
    Location
    Phoenix, AZ
    Posts
    624
    In addition to setting the baud rate to 33 kbit/s you will need additional hardware to work with SW CAN.

    GridConnect sells an adapter for $170:

    http://www.gridconnect.com/au5790.html

    Or you can roll your own using a "normal" CAN transceiver (e.g., MCP2551) and a SW CAN transceiver chip (e.g., NCV7356). Total parts cost <$10.

    Notice that GridConnect's adapter will not work with ElmScan 5 or OBDLink out of the box (the pinout is different).

    Best regards,

    Vitaliy
    OBDLink MX: world's smallest, fastest, most advanced OBD/Bluetooth adapter with SW and MS CAN support. Read the review to learn more.
    Need to look up a diagnostic trouble code? Try the most up-to-date, free DTCsearch.com!

    You cannot send me a private message using this forum. Use my email instead: vitaliy[@]scantool.net.

  3. #13
    Low Bitrate
    Join Date
    Dec 2009
    Posts
    78

    Thumbs up

    Thanks Vitality for the good info.

    I wish I had the smarts to make that circuit.

  4. #14
    Low Bitrate
    Join Date
    Jul 2005
    Location
    Michigan
    Posts
    70
    If you are looking to view SW can data you can also look up the Peak Systems (PCAN-AU5790) device. This will convert SW CAN to Dual Wire and DW CAN to SW.

    You can find out if you car has GPS over CAN by looking at the OBD II connector and try to find PIN 1. This is typically in the top left of the connector (PIN 1 is at the left of the wider part of the connector).

    If there is something there, then you have SW CAN. If you see something in PIN 2 (just right of PIN 1). Then your car uses J1850 (aka Class 2). Of course you car has to be equipped with OnStar as well.

    Good Luck.

  5. #15
    Low Bitrate
    Join Date
    Dec 2009
    Posts
    78
    The ELM327 can be configured and wired to communicate on the GMLAN bus.

    see my notes and pictures at: www.gtosoft.com under "coming soon".

    Just wanted to follow up so nobody spins their wheels

  6. #16
    Low Bitrate
    Join Date
    Dec 2009
    Posts
    78
    Some samples of how GMLAN can be used to control stuff from Android phone:

    http://www.youtube.com/user/gtosoft

  7. #17
    Low Bitrate
    Join Date
    Dec 2009
    Posts
    78
    I modified a few DX adapters for use on SWCAN network:
    http://cgi.ebay.com/ebaymotors/ws/eB...m=260663848162

  8. #18
    Newbie
    Join Date
    Oct 2012
    Posts
    1
    Hi
    Do U know where I can get the gap: URL scheme/protocol
    specification/ABNF/rules ?
    I'm implementing a server and need to differenciate
    between valid/invalid URLs.
    thx

Page 2 of 2 FirstFirst 12

Similar Threads

  1. hacking gps datacd
    By marsjell in forum Software & Software Development
    Replies: 28
    Last Post: 05-01-2003, 02:58 AM

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •