Pocket PC Multiple Bluetooth Devices GPS/OBDII

So I've got the (brilliant) Racechrono working on my iPAQ Hx4700 working with my BT GPS which uses a Serial Port to connect to the pocket pc. I've also bought a BT OBDII interface, using the ELM327 module, which also uses a serial connection to connect to the iPAQ. Now this is where it gets tricks, as when I have one connected, and I try to connect the other, it tells me I cannot, because I've already got a serial connection. I've tried this running WM2003SE and WM6.1 on the 4700. From a bit of googling, it appears BT doesn't support dual serial connections, or dual connections of any profile. I've got racechrono working with just the GPS and the OBD data working with just the OBDII device with OBDGauge, but never at the same time.

How then are people managing to get both of these running simultaneously? I would've thought both devices would use serial communication to relay their data.

Thanks for this great bit of software, just hope I can get it all working together.


  • Oh, I have to try the OBD-II on my loaner iPAQ, when I get back from my holidays (two weeks).
  • edited July 2009
    Thanks mate, appreciated

    My guess, is that other devices support multiple serial connections, I think it's an inherent limitation of the BT stack within the WM O/S, by my googling of the issue.

    I'm assuming that everyone's GPS uses a serial connection. And that also OBDKey (or any other generic ELM327 reader) uses a serial connection profile as well.

    Frustrating having the parts and not being able to put the pieces together

    Thanks again!
  • aolaol
    edited July 2009
    Does your iPaq have the Microsoft Bluetooth stack? I guess so as RaceChrono supports WIDCOMM only through "COM ports", and I don't think you can assign two ports like that. My loaner iPaq has the WIDCOMM stack...

    I need to do a bit of testing to figure out what is the common nominator for devices that the two Bluetooth connections does not work. On my WM 6.1 Touch Diamond this works flawlessly, and several of my users have reported as well that they are having no problems with it. On my WM 6.0 device I'm not sure if I ever tested this, I guess I need to do that ...
  • Guess what, it turns out it's WIDCOMM stack. So that looks like it's the culprit in supporting both devices simulatenously

    I've tested this in WM2003 and WM6.1 on the same device.

    Given the XDA developers have managed to WM6.1 on a non supported machine, I'm wondering if any of them have changed the stack.

    Thanks aol.

    Now to ponder for solutions.
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