[aprssig] Tomtom's For APRS (Question)

[Stephen H. Smith]

On 4/1/2012 1:48 AM, Pat Cook wrote:
> How reliable are they?
>
> The reason I ask is that saw some at the local Walmart for under $100.
>   Thinking of getting one IF they're reliable&  make good GPS RXers
>
>

With the exception of the GeoSAT AVmap with it's explicit APRS support and 
actual RS232 serial port (and the long-discontinued Garmin Nuvi 350), car 
navigator GPS units are basically useless for APRS applications.

1)    They only provide USB interfaces.  You *MUST* have a classic RS-232 
*SERIAL* interface to use GPS devices with TinyTracks, Kenwood radios, and 
other non-computer APRS devices.  USB interfaces are only usable with 
computer-based hosts.

2)    GPS USB interfaces normally are only for charging the internal battery 
and/or uploading updated maps, points of interest, music, photos, etc into the 
device.   No live GPS data is available at the port in most devices.

3)    Some current Garmin Nuvis that feaure the FMI feature ("Fleet Management 
Interface" intended for commercial vehicle tracking systems)  can provide GPS 
position data out, but you will need the specialized Argent Data "G-trans" 
cable to convert from proprietary binary USB data format to RS-232 NMEA 
format.    Even with the G-Trans cable, they won't function as mapping displays 
for incoming data -- only as a source of your own position for transmission.

-------------------------------------------------------------------------------

--

Stephen H. Smith    wa8lmf (at) aol.com
Skype:        WA8LMF
Home Page:          http://wa8lmf.net

*****  NEW   Precision Mapping 9 For UIview Released! *****
    http://wa8lmf.net/aprs/PMap9_Notes.htm


  Vista & Win7 Install Issues for UI-View and Precision Mapping
     http://wa8lmf.net/aprs/UIview_Notes.htm#VistaWin7

30-meter HF APRS over PSK63
    http://wa8lmf.net/APRS_PSK63/index.htm

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