Just trying to help out. If the problem does boil down to not enough power,
a temporary, but not very portable solution, is one of the USB hubs that has
an AC adapter.
----- Original Message -----
From: "Joseph Lee" <[email protected]>
To: "BrailleNote List" <[email protected]>
Sent: Monday, January 11, 2010 3:34 PM
Subject: [Braillenote] Few questions about USB problems
Hi folks,
I'm doing some investigations into our Apex USB problem. So far, I have
narrowed the issue to power management - supplying not enough power to
power the device in question. It is not related to file system - the
question of file system has been answered by the OS.
Few things to note:
* Windows CE itself does not support NTFS.
* We know that Apex has USB 2.0 ports, and there are three of them.
* We know that a USB device is supposed to wait until the host (the
computer) allows it to use more power.--Source: Wikipedia. "Universal
Serial Bus" article.
* There were reports that Apex's battery does not last as long as mPowers
have been (at least what we have so far).
So, the obvious question is, "does Apex supply enough power to its USB
ports just to power the devices connected to it?" If it does, as it is
expected, then we have a device-host negotiation problem between a USB
device and the Apex regarding power usage. If not, then we have a
"confused" USB host controller or the USB driver in question (in this case
USB Mass Storage Class driver).
If this issue is not fixed (at least addressed) soon, we would have a
"zombie" port - a USB port that is supposed to work with a variety of USB
storage devices, but the situation says otherwise. I really hope that
this problem is fixed soon.
Cheers,
Joseph
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