USB Device not always detected

[Keith Rathband]

I am trying to use a USB modem on my device. The modem i'm trying to use is
a Sitecom DC-009, and the device is running on a VIA400Mhz CPU with VIA
chipset.
I cannot get my device to always detect the modem when its plugged into the
USB port.
I have tried i different make of modem with my device - and that one is
always detected.
I then tried the sitecom modem on a standard destop machine (compaq) running
XP-pro - it works fine.
I then installed XP-pro on my device - again the sitecom modem is'nt always
detected.

This all points to somthing wrong with my device - but i thats the case how
come it can realiably detect different makes of modems.

Any suggestions ?

Keith Rathband

 

[KM]

Keith,

Sounds to me like your are missing the modem's driver dependencies. Have you
componentized the driver yourself?
As you mention another modem was working fine, I imagine the required USB
stack is included in to your runtime.
In any case you can use FileMon/Regmon/Dependency Walker tools to find out
what's missing from your image.
Also, to make sure the modem will work on XPe properly, you may try it with
a big XPe image that includes pretty much all software components
(XPProEmulation under Development Utilities/Main folder on
www.xpefiles.com).

 

[David D]

This may or may not be pertinent to you.
Is your VIA 400Mhz CPU an advantech board?
We use that on ours and we found that the board was missing some USB pull
ups.
The result was that any newer USB device or any USB 2.0 device did not work.
After adding some 15K pull ups on the USB lines, everything worked.