Freerunner as a mobile gateway -> shipping container

[Al Johnson]

On Wednesday 18 May 2011, Eric Smith wrote:
> Thanks Al,
> 
> Main application here is in a sea shipping container.

Good luck getting a signal when they're stacked! I guess you can find 
somewhere to stick the antennae where they won't be too vulnerable and have a 
fair chance of getting a signal.

> The key issues are RF communication (when in a GSM range of course)
> and power management due to the long haul journey including journey
> overland. Power supply has to be in the form of an additional battery.

Battery, efficient dc-dc converter, y-cable. Do some current measurements and 
size accordingly.

> Technical issue is to have minimal size OS and to be low in power
> consumption.  And robust.

OpenEmbedded, OpenWRT, debian would all work. Choice is probably more personal 
preference and familiarity than anything technical. FSO provides control via 
dbus for most stuff if you don't want to do the low level stuff yourself. 
Remember to turn the GSM and GPS off before suspending!

> All ideas welcome.

Sounds like a bog standard monitoring job. Do you need something as powerful 
as the moko, or would an AVR do the job?

> Thanks
> 
> > On Tuesday 17 May 2011, Eric Smith wrote:
> > > Hi
> > > 
> > > I am considering using the Freerunner as a mobile gateway to track
> > > GPS on a vehicle and to receive data from wireless sensors in the
> > > vehicle and send the sensor data and GPS data through GPRS.
> > > 
> > > We may need to plug a customised wireless device into the freerunner
> > > usb. An external GSM and GPS antenna will be used. The device will
> > > have to run reliably and be robust for 8 to 12 weeks, so that means
> > > a customised battery.
> > > 
> > > Power use efficiency means putting keeping the device in low-power
> > > consumption mode for most of the time and waking every 30 minutes
> > > (say) for polling and transmitting.
> > > 
> > > Has anyone implemented such a solution or has ideas about feasibility?
> > 
> > Nobody has talked about doing this IIRC, but it certainly sounds
> > feasible. External power can be supplied via the usb y-cable
> > arrangement, so shouldn't be a problem. atd-over-fso will let you wake
> > from suspend to do what you want on an interval.