[Xastir] IS to RF igating

[Kurt]

Noooo way I could have come up with that script.  The Egg Finder
is a nifty $90.00 kit.  Tom mentioned a fix in xastir.cnf to get 
the GPS strings to be transmitted more frequently.  I've tried 3 and 4 seconds 
and it seems to work.

As a quick review, the tracking solution sends NMEA strings to a receiver.
One simply plugs the receiver into Xastir like it's a run-of-the-mill USB
GPS receiver. Modifying Xastir to transmit this "cross-band" APRS packet once every 3 or 4 seconds allows me to use a D72/Garmin GPS to track it portable with a map in hand. Plus it's 
easier to read a Garmin GPS in the sunlight as opposed to a laptop screen.
Remember, I'm doing this OFF the national frequency. 

The laptop is good to have to record the data to save for later use. A non-ham could
use it too.  Simply monitoring the 915mhz frequency and not transmitting in the ham
band.

I'm going to see if I can get a linux distro on a Nexus 7 2013 and run Xastir there.
The receiver I'm using can be attached to a B/T module so I could send the data
wirelessly to the Nexus.  If I can get Xastir to recognize the internal GPS, I'd go ahead 
and use the gps2aprs.pl script and be able to walk directly to the tracked rocket.
This solution of course wouldn't be crossband repeating so a non-Ham flyer could 
use it also.

                                Kurt KC9LDH
                          (I can read but don't know how to program!)  :-)
--------------------------------------------
On Sat, 3/22/14, Jason KG4WSV <kg4wsv at gmail.com> wrote:

 Subject: Re: [Xastir] IS to RF igating
 To: "russo at bogodyn.org" <russo at bogodyn.org>, "Xastir - APRS client software discussion" <xastir at lists.xastir.org>
 Cc: "Kurt" <ksaves2 at sbcglobal.net>, "xastir at xastir.org" <xastir at xastir.org>
 Date: Saturday, March 22, 2014, 4:24 PM
 
 
 > On Mar 22, 2014, at 2:11 PM, Tom Russo <russo at bogodyn.org>
 wrote:
 > 
 > Yeah, since that script just takes the raw NMEA strings
 and tacks on an APRS
 > header, it's extraordinarily simple.  
 
 I was going to say idiot simple. :). It doesn't even check
 for correct checksums, just a simple RE match to make sure
 it looks like a valid NMEA sentence.  It needs to pick
 out GPGGA and GPRMC sentence pairs to make a valid APRS
 position report. 
 
 As Tom says it really needs to be an APRS client
 implementation to work well.  Kurt is ahead of me in
 implementing this, but he cheated and used COTS hardware
 while I've been busy building my own (maybe he's just
 smarter).  :)
 
 The bulk of the code is rs232 handling that someone else
 wrote and my hack isn't properly documented to give credit
 and I don't even recall what the copyright/licensing may
 have been or where I downloaded it. That's why I'm not
 really advertising. I don't care if anyone wants to use it
 for themselves.
 
 With all the rf hardware currently available that's cheap
 and fast, it'd be nice to have tracking that can keep
 up.  Even though 2m 1200 baud can't handle it, even the
 retired d7 can do 9600 baud.
 
 I'm kinda on the fence with my rocket tracking, as current
 APRS systems can't really keep up - cots rf modules are
 cheaper and faster and in most cases license free. Still,
 the applications are more mature, and nothing beats xastir -
 that's why I try to feed all my tracking data into xastir
 for consumption. 
 
 -Jason
 kg4wsv