Raspberry PI + 3G Dongle

Oh the headache! I believe after a week of fiddling I've final got my head wrapped around this madness.

There are two primary issues that need to be taken care of when using a 3G dongle with a PI 1. A USB modem has schizophrenia! 2. Network connectivity is not "always" available.

So what do I mean "schizophrenia"? Simple, the modem actually wants to a usb cdrom/flash and assumes this personality by default in most cases. the command lsusb will list the current detected device. if it is not correct usb_mode_switch must be used to remind it that it should actually be a modem.

On point 2, sakis3g is a nifty tool to get you connected once you have figured out all of the "required" parameters. Its shortfall is that it never maintains the connection, i.e. if a connection is made and due to bad signal the connection is "lost" sakis3g runs like normal without ever telling you or attempting a reconnect. This is where UMTSkeeper comes in. This small yet feature packed tool maintains connectivity as well as logs network statistics! amongst other features that I have not played with.

Once you have all these 3 components working in harmony you should have a sweet "always" connected PI.