[Xastir] mobile / handheld xastir on the pi - work in progress

[Jason KG4WSV]

tl;dr  For about US$150 it looks like you can have a functional dedicated
mobile xastir rig.


So I've gotten my hand on a Raspberry Pi 3 at work.  I had previously
avoided the pis because they seemed to be touchy about power and
underpowered CPU-wise. My initial attempt at a mobile xastir had been on a
beagle bone black with a 7" resistive touchscreen from 4D.  It was OK-ish,
but the touchscreen wasn't really useful without a stylus (grab one meant
for a Nintendo DS if you're playing with resistive touchscreens) and dim -
not readable in sunlight.

The Pi 3 is a different animal - quad core at 1GHz.  This one seems pretty
useful. I tried it with a pig of a java application that the BBB just
couldn't handle, and it worked fine.  Xastir here I come.

The build was trivial using the Ubuntu directions.  I used my old standby
pile of shape files (one state of TIGER shape files from the '04 dataset
plus national atlas for the big picture).  It runs just fine.

Now to take it portable/mobile.  There are lots of HDMI displays and
touchscreens available. I got my hands on the "Pi Foundation 7"
Touchscreen" which is only 800x480 resolution, but has a capacitive
touchscreen.  It's a tablet display with driver hardware to connect it to
the Pi.  I mounted it in a SmartiPi case which packages the whole thing
(sans power) nicely. It's quite functional on the bench.  I hope to take it
to a rocket launch this weekend to see how well it works in the field - I'm
working on a battery pack for it now.  It's tailgate ground station ready,
but not quite field portable (but that's OK, i've got a D7).

The Pis storage is a microSD card. You can store a metric crapload of shape
files on one - if you want to spend the money on the SD card. I've seen uSD
up to 256Gb, but IIRC the largest reported used with the Pi 3 is 64G.  I'm
using 16 at the moment.

For the truck it's a possibility that needs testing.  It could be OK, or I
may be better off with a higher resolution 10" display and use one of the
little media center type keyboard/trackpad combos to deal with user IO.

This is a work in progress, but I thought I'd throw it out anyway.

-Jason
kg4wsv