Netgear 340u

[Bjørn Mork]

Noah Taber <noahtaber at gmail.com> writes:

> I don't think I am able to communicate through the serial interfaces of the
> 340u for some reason, thus I don't think I can issue ATi commands.
>
> I have tried minicom and gcom (or comgt now) to ttyUSB0, ttyUSB1 and
> ttyUSB2.  None of the tty interfaces respond.

Note that only ttyUSB2 (normally - really the device corresponding to usb
interface #3) will support AT commands.  The other two serial interfaces
are Device Management (use libqcdm) and NMEA (GPS).

>  There is no output with
> minicom.  Below is the output with comgt:
>
> $ sudo comgt -d /dev/ttyUSB2
>  ***SIM ERROR***
> Check device port configuration.
> Check SIM is inserted
> Test SIM in a mobile phone?
>
> What are your thoughts regarding this?

I'm starting to think that there might be a problem with usb bulk data
in general on your platform.

Note that the QMI control channel only depend on control and interrupt
usb traffic.  This works OK.  But both network and serial data use usb 
bulk endpoints as transport, and this seems to fail consistently.

Maybe you should test the modem on a Linux PC with similar software
versions...

For debugging the usb issues on the raspberry pi, you could try out
usbmon.  See https://www.kernel.org/doc/Documentation/usb/usbmon.txt
for instructions.  Do usb-storage devices work, BTW?



Bjørn