Hi,

I don't think that your problem is related to your packet size but
most probably to linux drivers.

>> I have one mote acting as a BaseStation, which randomly changes port 
>> (/dev/ttyUSB0->/dev/ttyUSB1)
Do you mean that the port changes at runtime or between 2 executions
of SerialForwarder ?

If the port changes at runtime, I would assume that the USB link gets
shortly broken and up again and thus the driver mounts the USB-serial
converter on another ttyUSB.

There are ways to configure Linux/udev to always mount the same
hardware on the same ttyUSB port. I only have a link to a french blog
entry I could remember.
http://www.lefinnois.net/wp/index.php/2009/04/15/ttyusb0-ttyusb2-non-ttyusb1-graaaahh-udev/

Basically, you can force udev to mount a device to a fix port based on
its serial number.

You can retrieve the serial number of your USB converter with:
$udevadm info -a -p  $(udevadm info -q path -n /dev/ttyUSB0)

and then update your /etc/udev/rules.d accordingly.

This is only part of the solution (will always mount the serial link
on the same ttyUSB port) but it does not explain why the device gets
disconnected and connected again... Have a look at the output of dmesg
to see if your Linux host really detects disconnects...

In case of disconnection you should see something like:
[191876.912510] ftdi_sio 2-1.4.1:1.0: device disconnected

and later again a connection

[191886.215902] usb 2-1.4.1: new full speed USB device using ehci_hcd
and address 10
[191886.331193] usb 2-1.4.1: configuration #1 chosen from 1 choice
[191886.333078] ftdi_sio 2-1.4.1:1.0: FTDI USB Serial Device converter detected
...
[191886.333747] usb 2-1.4.1: FTDI USB Serial Device converter now
attached to ttyUSB0

Hope this helps,

Romain

On Thu, Jun 16, 2011 at 12:27 PM, colum walsh <[email protected]> wrote:
> Hi list,
>
> I have one mote acting as a BaseStation, which randomly changes port
> (/dev/ttyUSB0->/dev/ttyUSB1), causing SerialForwarder to stop working. Has
> anyone else had this issue?
>
> My packet size is larger than standard, could that be the cause? Or
> something to do with linux drivers?
>
> I'm using tmote sky motes, tinyos-2.1.1, and Ubuntu Lucid.
>
>
> Thanks for your time,
> Colum
>
> _______________________________________________
> Tinyos-help mailing list
> [email protected]
> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
>
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