[aprssig] Garmin eTrex Legend Question

R. Simmons pelican2 at silcom.com
Mon Jul 9 12:15:14 EDT 2007


Amen to that !

 This much-vaunted USB standard is a nightmare for little guys who want to
build their own interface... in spite of all the articles describing how to
make them, none seem to describe ( in detail ) the invisible transactions
that go on between the two devices, before a single byte of data can be
sent.

Basically, to do what this fellow is suggesting, the destination device
needs to behave like a full-tilt IBM PC "host" computer, not some little
device with an embedded micro.

Bob S.


----- Original Message -----
From: "'Scott Miller'" <scott at opentrac.org>
To: <gerheim at cox.net>; "'TAPR APRS Mailing List'" <aprssig at lists.tapr.org>
Sent: Monday, July 09, 2007 8:42 AM
Subject: RE: [aprssig] Garmin eTrex Legend Question


> You don't.  I really need to write up a FAQ on why you can't really do the
> other way with USB.
>
> The GPSmap 60CS has both USB and serial, so it's not an issue with this
> unit.  I hope to someday develop a host controller that'll work with some
of
> the other units, but it's going to be a major development project and I'm
> not sure it's even possible with many of the models.
>
> Scott
> N1VG
>
> > -----Original Message-----
> > From: gerheim at cox.net [mailto:gerheim at cox.net]
> > Sent: Monday, July 09, 2007 8:16 AM
> > To: TAPR APRS Mailing List
> > Cc: 'Scott Miller'
> > Subject: RE: [aprssig] Garmin eTrex Legend Question
> >
> > How do you connect the USB GPSRX to a serial device like a
> > D7?  I have some Serial/USB adapters, but they go "the wrong
> > way" - from a PC to a serial device, not from a USB "device"
> > to anything else.
> >
> >
> > ---- 'Scott Miller' <scott at opentrac.org> wrote:
> > > Same thing happened to mine.  Whacking it with the palm of
> > my hand would fix
> > > the display, usually.  As for it being watertight, the fact
> > that I opened
> > > mine up to try fixing the display issue may have
> > contributed to the lack of
> > > a good seal.  After several miles of riding underwater in
> > my cargo pocket as
> > > I hiked the Zion Narrows, my Legend finally died.  I
> > actually resurrected
> > > it, but the data input line never worked again, and in
> > trying to fix that I
> > > seem to have killed the rest of it.
> > >
> > > All of the ICs by Maxim on the board had corrosion around
> > the pads.  I think
> > > they were a different composition than the other parts -
> > you could see
> > > copper showing through.  In any case, I had a heck of a
> > time trying to make
> > > connections when the board had eroded right out from
> > underneath the parts.
> > > >From the looks of it, it had probably been corroding
> > already before the Zion
> > > trip.
> > >
> > > So yeah, it's probably time to upgrade.  My suggestion is
> > the GPSmap 60CSx.
> > > I've got the 60 CS and love it, and the CSx has the
> > improved SiRF receiver
> > > and external memory slot.
> > >
> > > Scott
> > > N1VG
> > >
> > > > -----Original Message-----
> > > > From: aprssig-bounces at lists.tapr.org
> > > > [mailto:aprssig-bounces at lists.tapr.org] On Behalf Of
> > gerheim at cox.net
> > > > Sent: Monday, July 09, 2007 5:28 AM
> > > > To: APRSSIG Mailing List
> > > > Subject: [aprssig] Garmin eTrex Legend Question
> > > >
> > > > Somewhat off topic, but I know some of you folks own the
> > > > device in question.
> > > >
> > > > I've owned it for several years.  The glue holding the rubber
> > > > bumper to the perimeter has weakened.  This may be a
> > > > coincidence, but the display is also going freaky from
> > time to time.
> > > >
> > > > 1) is it still watertight?
> > > > 2) is it time to upgrade?
> > > >
> > > > If it still pumps out NMEA output, I can still keep it as a
> > > > data source for GPS, but use another GPSRX for display and
> > > > navigation.
> > > >
> > > >
> > > > --
> > > > -Al Gerheim
> > > >
> > > > HP-49G+ Software Page:
> > > > http://members.cox.net/above
> > > >
> > > > _______________________________________________
> > > > aprssig mailing list
> > > > aprssig at lists.tapr.org
> > > > https://lists.tapr.org/cgi-bin/mailman/listinfo/aprssig
> > > >
> > > >
> > >
> > >
> > >
> > >
> > > _______________________________________________
> > > aprssig mailing list
> > > aprssig at lists.tapr.org
> > > https://lists.tapr.org/cgi-bin/mailman/listinfo/aprssig
> >
> > --
> > -Al Gerheim
> >
> > HP-49G+ Software Page:
> > http://members.cox.net/above
> >
> >
> >
>
>
>
>
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