[aprssig] Nuvi 350 still on sale thru the end of Aug 09 WEB Only

Wed Aug 26 00:54:11 EDT 2009

Thanks Stephen,

This line answers my question and did not find this when I looked on the web
site, basically states that with the GTRANS with -DSUB, it will then drive a
laptop serial:

The G-Trans cable is also available with a standard DB9 serial plug on the
end rather than the 2.5mm stereo miniplug used by Kenwoods.  (The GPS data
OUT should be usable by ANY device (tracker, laptop, etc) that accepts
normal RS-232 4800 baud NMEA 0183 GPS data.   The waypoint data IN would
depend on the capabilities of the attached device.)  Details on the
alternate G-Trans cable here

Michael

  _____  

From: aprssig-bounces at tapr.org [mailto:aprssig-bounces at tapr.org] On Behalf
Of Stephen H. Smith
Sent: Tuesday, August 25, 2009 9:47 PM
To: TAPR APRS Mailing List
Subject: Re: [aprssig] Nuvi 350 still on sale thru the end of Aug 09 WEB
Only

Michael Hatzakis Jr MD wrote: 

I am considering buying one of these Garmin 350's to power APRS in a laptop
and other GPS functions, is this a standard serial/USB compatible signal? 

NO!   By itself, it won't do ANYTHING!    The Nuvi has a USB interface, but
it doesn't, by default, provide live data out in any format.   The normal
USB interface is intended primarily for uploading software patches, updated
maps and user-created points-of-interest lists TO the device. Live GPS
position data DOES NOT normally come out of the device.  

How about for an Icom IC91D?  What will it take to make it compatible with
serial/USB, and for the IC91AD?   

ideas for a technically savvy person?

Michael  K3MH

  _____  

Certain Nuvi models, including the 350, have a built-in firmware/hardware
feature called FMI (Fleet Management Interface).  When the conductors of the
USB port are pulled up or down with suitable value resistors inside a
special cable, the USB interface "automagically" transforms itself into a
classic serial interface instead.  This enables real-time download of GPS
data and upload of waypoint data for plotting objects on the screen.   

FMI also offers a messaging interface that uses the soft keyboard display
normally used for entering addresses to compose text messages for
transmission.  Unfortunately all these goodies are in a proprietary Garmin
protocol, intended for developers of custom commercial AVL/messaging
systems.  Some details are here:

      <http://www8.garmin.com/solutions/pnd/>
<http://www8.garmin.com/solutions/pnd/>

Some of the Garmin units that support this hidden mode are listed here:

     <http://www8.garmin.com/solutions/pnd/supportedproducts.jsp>
<http://www8.garmin.com/solutions/pnd/supportedproducts.jsp>

>From the standpoint of APRS users, the only two devices that can directly
exploit the Fleet Management Interface are:   

o     The Argent Data "G-Trans" cable for the Kenwood APRS radios.  This
device has a mini-USB plug on one end (to go into the Garmin), and a 2.5mm
stereo miniplug on the other (to go into the Kenwoods' dedicated GPS serial
port).   This cable, with an embedded microcontroller in a "goiter" in the
middle of the cable,  translates Garmin FMI live position data from the Nuvi
to serial standard 4800 baud NMEA ASCII for use by the Kenwoods and other
NMEA-using devices.   

The Kenwood APRS radios are capable of translating incoming posits received
from other station into NMEA $GPWPL waypoint strings which can be sent back
to many display GPS devices that accept and plot waypoint data. This data is
fed OUT of the dedicated GPS port on the Kenwood radios,  BACK to the GPS on
the other half of the serial cable bringing GPS data TO the radio.  

If this feaure is enabled in the Kenwood radio, the G-Trans cable will
convert $GPWPL waypoints back to Garmin FMI format for display on the Nuvi
350's maps.  Details on this cable for the Kenwood radios here:

<https://www.argentdata.com/catalog/product_info.php?cPath=28&products_id=11
3>
<https://www.argentdata.com/catalog/product_info.php?cPath=28&products_id=11
3>

The G-Trans cable is also available with a standard DB9 serial plug on the
end rather than the 2.5mm stereo miniplug used by Kenwoods.  (The GPS data
OUT should be usable by ANY device (tracker, laptop, etc) that accepts
normal RS-232 4800 baud NMEA 0183 GPS data.   The waypoint data IN would
depend on the capabilities of the attached device.)  Details on the
alternate G-Trans cable here:

<https://www.argentdata.com/catalog/product_info.php?cPath=28&products_id=11
4>
<https://www.argentdata.com/catalog/product_info.php?cPath=28&products_id=11
4>

o     The Argent Data Tracker 2 (tracker & send/receive TNC) which can use
the Nuvi 350 as a GPS source for the tracker, and the screen as an APRS
mapping display and messaging terminal.    [The program code for dealing
with the FMI protocols are built into the T2's firmware.]  The T2 has to be
connected to the Garmin with the DB9 version of the G-Trans cable. 

Note that these are open-sourced devices, so the program code for dealing
with FMI is visible and can be used as a starting point for developing
similar capabilities in other software. 

  _____  

--

Stephen H. Smith    wa8lmf (at) aol.com 
EchoLink Node:      WA8LMF  or 14400    [Think bottom of the 2M band]
Skype:        WA8LMF
Home Page:          http://wa8lmf.net

JavAPRS Filter Port 14580 Guide 
  http://wa8lmf.net/aprs/JAVaprsFilters.htm

"APRS 101"  Explanation of APRS Path Selection & Digipeating 
  http://wa8lmf.net/DigiPaths 

Updated "Rev H" APRS            http://wa8lmf.net/aprs
Symbols Set for UI-View, 
UIpoint and APRSplus:

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