[beagleboard] Weird Wifi Issues

Hi All

Sorry if these questions have been asked and answered before, I have
been searching the group archive for the past few hours and nothing
mentioned seems to work.

Firsltly a bit about my hardware setup. I am using a Revision B7
Beagleboard, running Angstrom a slightly modified console image to
include tftp, ftp, apache2, Kernel version 2.6.29, r35 i think.

I am using a TPLink TP-WN422G usb wireless stick. This uses the ZyDAS
WLA-54L chipset and the zd1211 driver. This is connected via a Belkin
USB Hub. I have added an entry into the interfaces file to allow the
system to automatically connect to my wireless access point.

I intend to power the system via a 5V-2A regulator from
RoboticsConnection and use a 3700 mAh Nimh battery as the source.
However to exclude any issues with the regulator, I am powering the
BeagleBoard directly from a wall socket. The USB is still powered
through the regulator.

OK now is the weird thing, more often than not the wireless stick is
detected, however only very rarely does the firmware full load.
Messages note an error number -2.

Hi,
  Sounds kinda like a power problem even though you have looked at
that from two
directions. You should, with a VOM, measure that between 4.75vDC -
5.2vDC is
going to your Beagleboard. Too much can cause issues, overheating and
eventual
magic smoke. Too little and intermittent issues.

All I can come up with atm...
Don Lewis

Hi Don

I thought that might be a problem and checked before posting my
initial message. The voltage at the output of the regulator is 4.97 V
DC.

Although, I think I may have a clue as to the usb problems which has
been summarised on the following page: http://elinux.org/BeagleBoardFAQ#USB_OTG_connection_.233

However, this does not fully answer why the wifi (even when
recognised) sometimes come up and some time does not.

I have also found that when the link does not become active at boot,
if I issue a ifdown wlan0 and the ifup wlan0, the link becomes active.
This to me sounds link a very awkward timing issues that may not be
easy to resolve.

Any other suggestions?

Regards

Chithambaram