[aprssig] USB interface to d700a

[wa8lmf2 at aol.com]

-----Original Message-----
From: Michael J. Wolthuis <wolthui3 at msu.edu>
To: 'TAPR APRS Mailing List' <aprssig at lists.tapr.org>
Sent: Thu, 2 Feb 2006 10:50:17 -0500
Subject: [aprssig] USB interface to d700a

   In looking at the new Garmin GPS units I see the majority of them say 
PC/USB
interface.  I assume this means they have a USB interface and not serial
only?  How can this be connected to the d700a directly without a 
computer?


They can't.

USB HAS to have a master (a.k.a. host - normally a computer) to assign 
the slave devices (a.k.a. "cliient") their identities.   The common 
USB-to-serial adapter "dongles" used with new serial-port-less laptops 
are client devices that MUST be initialized by a complex multi-layer 
software driver stack in a PC before they can function.  They CAN NOT 
stand alone to convert a USB client device (like the USB  Garmins) 
backwards to serial.