[Xastir] Mish-mash of questions

[Lee Bengston]

On Sun, Oct 30, 2011 at 3:41 PM, Dale Seaburg <kg5lt at verizon.net> wrote:

> Lee Bergston:  You've given me some excellent ideas for the vehicle side of
> this application.  The expense of the added PC is nearly an even offset to
> the wifi-to-serial adapter - they "ain't" cheap!  With the AGWPE, I save on
> the TNC too.  No experience with AGWPE, but I think that's right - it's a
> soundcard modem.  Correct?  Don't know quite yet how I would do the
> frequency flipping with this arraignment.  Any ideas?  The radios I have in
> mind I think would take a simple relay with SPDT contact set to select
> between the two frequencies.

The original AGWPE (AGW Packet Engine) software is very commonly used
to enable a soundcard as a TNC, but it can also be used with real
TNC's.  When used with either a real TNC or a soundcard, it provides
an external IP interface that can be used by other computers that need
to access the radio.  APRS clients including Xastir can use the AGWPE
interface to connect to the radio.  AGWPE is a Windows application.

Given you are already using Linux, I was suggesting ldsped,
http://www.on7lds.net/ldsped/, which is a Linux program that
essentially mirrors AGWPE functionality in Linux - including cloning
the external IP interface.  As a result, APRS software originally
designed to connect to a Windows computer running AGWPE can also
connect to a Linux computer or even a Linux based device like a
wireless router when it is running ldsped.

In order to use ldsped with a real TNC, the TNC needs to be in KISS
mode, and the serial port to which the TNC is connected needs to be
configured as an ax25 interface.  It sounds like one of your eBay
obtained tablets could be used as the host computer in a vehicle, but
it could be any computer running Linux that's convenient.  Netbooks
aren't the rage any more, so I would expect eBay to be full of deals
in that space as well.

You have plenty of choices - the vehicle computer could be running
Windows/AGWPE or Linux/ldsped, and the remote users could use either
Xastir, UIView, or APRSIS32 - they all have AGWPE as an interface
option.  I'm running ldsped on a small Acer "Revo 1600" "nettop" PC,
which is basically a netbook motherboard in a small enclosure for
desktop use. The Acer PC is connect to the TNC via a usb to serial
adapter.  I can access the tnc/radio combo from any computer in the
house thanks to the cloned AGW interface provided by ldsped.  Others
have accomplished more impressive feats by running ldsped on smaller
devices like a sheeva plug pr wireless router.

Regards,
Lee - K5DAT