RaspberryPi 2 with Huawei E398

[Dan Williams]

On Fri, 2015-05-15 at 16:11 +0200, Aleksander Morgado wrote:
> On Fri, May 15, 2015 at 10:28 AM, John Whitmore <arigead at gmail.com> wrote:
> > I'm trying to put together a system which uses 2 Huawei E398 USB Dongles with
> > two different operator SIM's so that if one modem has no coverage the other
> > takes over.
> >
> > I've followed the debugging information on [1] to try and get my hands on the
> > logs but not sure where the NetworkManger is sending its logging info. I do
> > have the output from ModemManager, which I'll attach to this email.
> >
> > I'm not sure that the logging from ModemManager will be of any help at all as
> > it might not be the issue. What is happening is that I can establish a
> > connection but as soon as I start to do a ping test from the command line the
> > whole system freezes.
> >
> > This is with one 4G Dongle in place, I was hoping to be able to manage both
> > connections.
> >
> > I'm using raspbian 2015-05-05 with kernel 3.18.13
> >
> > If I can send on anything else please let me know. I'd really like to get this
> > system working. Unfortunately I've only got two E398 Dongles so I can't try
> > with a different modem at present. I'll try and get my hands on another.
> >
> >
> > [1] : http://www.freedesktop.org/wiki/Software/ModemManager/Debugging/
> 
> 
> Ouch; ModemManager 0.5.2 is way too old... Could you setup
> ModemManager 1.4.8 with libqmi to try?
> 
> Also, just to make sure, you are using an external *powered* usb hub
> to connect the modems to the RPi, right? The RPi cannot handle the
> power consumption of 1 single modem in connected state.

Good point; even some laptops cannot power modems adequately, hence they
ship Y cables with modems that pull power from 2 USB ports :)  Always
good to check this out when the modem crashes while connected.

Dan