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EB500 and simultaneous connection — Parallax Forums

EB500 and simultaneous connection

DorlingDorling Posts: 32
edited 2007-05-07 16:33 in General Discussion
I need to know if the Parallex EB500 can have simultaneous connections? If not, which ones out there do?

Also, has any one done any projects/work with the Lego Mindstorms NXT or RCX that communicates with the javelin?

I am planning to use the javelin and Mindstorm to communicate with each other via Bluetooth.

Thanks a lot

Jonathan Dorling

Comments

  • Peter VerkaikPeter Verkaik Posts: 3,956
    edited 2007-01-25 07:39
    According to product specs on Parallax site the eb500
    is compliant with the v1.1 standard.
    If the v1.1 standard supports simultaneous connections, then so should the eb500.
    Do you have a protocol description for the Mindstorm?

    Edit:
    the eb500 manual error list says for error 10:
    10 Unable to add a new trusted device. This error will occur if you attempt
    to have more than twenty five simultaneously trusted devices.

    So it looks there is a limit of 25.

    regards peter

    Post Edited (Peter Verkaik) : 1/25/2007 7:53:21 AM GMT
  • DorlingDorling Posts: 32
    edited 2007-01-25 10:35
    Thank you very much for that infromation peter

    Jonathan
  • DorlingDorling Posts: 32
    edited 2007-05-07 15:23
    It turns out that you can only have a maximum of 1 (one) simultaneous connections with the eb500. I have find out that LinkMatik 2.0 (by flexipanel) can have maximum of 4 (four) simultaneous connections. But the maximum for bluetooth is 7 (seven) simultaneous connections, so does any one know of any other Bluetooth device that uses the SPP (Serial Port Profile) so that i can use the bluetooth with the Lego Mindstorms NXT?

    Many Thanks

    Jonathan
  • Peter VerkaikPeter Verkaik Posts: 3,956
    edited 2007-05-07 16:04
    I don't know of such devices, but consider this:
    I think 4 simultaneous connections is all what the javelin can handle.
    For 4 halfduplex connections you need 4 uarts, that is 4 VP's. In case of full duplex
    connections, you can use 4 receive uarts and enable a transmit uart when needed.
    That requires 5 VP's. Then you probably also need the Timer VP to timely switch between tasks,
    which makes 5 (6 in case of fullduplex).
    Given that the javelin can only have 6 VP's running simultaneously, there is no point
    in having a device that can handle 7 simultaneous connections.

    regards peter
  • DorlingDorling Posts: 32
    edited 2007-05-07 16:33
    The LinkMatik 2.0 can handle 4 simultaneous connections using only 1 VP. If you have using eb500 then the maximum would be 4 in the way you are talking.

    So it is possible to have a 7 simultaneous connections on another device?

    Jonathan
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