GPS

wrote:

On Tue, 31 Aug 2004 18:22:12 -0500, Ron Hunter
wrote:


Prometheus wrote:


In article ,
writes


On Mon, 30 Aug 2004 06:16:02 +0100, Prometheus
wrote:


* Strictly speaking "RS-232" only reefers to the 25 way sub-miniature
connector and not the electrical connexions to the pins which are other
standards.


Are you sure? I believe I heard years ago that it defined only
signal levels (and maximum supported distance criteria for copper) for
25 lines and was otherwise connector-agnostic.

I may well be wrong -- it happened once. A long time ago.


I think you could be right, it was along time ago for me also. I just
did a bit of research, it seems it was originally a nine wire system.


Yes, in a 25 pin connector. Wonder why... The 9-pin connector came later.


Because of the remaining signals not normally required for
simple communications. Nine (or fewer) pins are probably adequate for
95% of what's done with serial comms.

Probably 95% require only THREE wires, so most of the time there are 6
pins in even the smaller 9-pin D connector that are wasted, along with
the space on the device. That's who some companies don't put serial
connectors on laptops unless specifically requested.

Prometheus wrote:

In article ,
writes

On Tue, 31 Aug 2004 18:18:49 -0500, Ron Hunter
wrote:

Prometheus wrote:

-----------Cut-----------

It would cost the manufacture money to redesign the integrated circuit
to provide USB in addition to NEMA, the customer would have to pay for
that through increased price.


Fine, up the price $20 I will pay!


The adapter to do the job is only a few bucks. Get shopping!


Or he could buy a GPS Rx with USB.

where? How much? Models?
I checked throughly about this time last year and found ONLY a model
intended for connection to a particular model of pocket computer, and
the interface wasn't USB.

Prometheus wrote:

In article ,
writes

On Tue, 31 Aug 2004 18:18:49 -0500, Ron Hunter
wrote:

Prometheus wrote:

-----------Cut-----------

It would cost the manufacture money to redesign the integrated circuit
to provide USB in addition to NEMA, the customer would have to pay for
that through increased price.


Fine, up the price $20 I will pay!


The adapter to do the job is only a few bucks. Get shopping!


Or he could buy a GPS Rx with USB.

where? How much? Models?
I checked throughly about this time last year and found ONLY a model
intended for connection to a particular model of pocket computer, and
the interface wasn't USB.

wrote:

On Tue, 31 Aug 2004 22:32:43 +0100, Prometheus
wrote:


In article ,
writes

On Mon, 30 Aug 2004 19:17:05 +0100, Prometheus
wrote:

-Cut------------

We are talking about a digital compass using old fashioned magnetism,
not GPS. The GPS compass only gives a bearing when you are moving, which
is of no use when standing still taking photographs.

Some more recent ones will tell you the direction they're
pointed even when standing still. I believe they use a fluxgate
compass rather than doppler shift as the others do while in motion.

They do use a fluxgate; I thought the GPS signal derived compass used
change in position, otherwise it would not work if you walked too
slowly.


OK, now Ive forgotten. Those without a fluxgate use doppler
shift (not successively computed positions) to calculate speed, but
I'm not sure which they use for direction. They do generally cut out
below a couple or so mph.

Dave M probably knows the correct answer off the top of his
head.
My GPS will give good heading data at normal (2-3mph) walking speed.

wrote:

On Tue, 31 Aug 2004 18:25:58 -0500, Ron Hunter
wrote:


wrote:


On Mon, 30 Aug 2004 21:02:08 -0500, Ron Hunter
wrote:



Mxsmanic wrote:



Ron Hunter writes:




And a keyboard is the only thing you have on a USB interface?


I have two devices on USB, because that's all they support. One of them
requires that it not share the interface with anything else, which
pretty much blows one of the major advantages touted for USB.

That's out of three computers, too. I have three devices on serial
ports. I have four devices connected via SCSI. I have two devices
connected via PS/2 interfaces.

The keyboard is not among the devices connected via USB, because I like
to keep things simple, and I prefer a keyboard that works no matter what
state the system is in.




It would take dozens of serial ports to equal the data
handling capacity of one USB 2.0 port.


I don't need the data-handling capacity of a USB 2.0 port for the
devices I have connected via serial ports.


No, but in order to transfer megabytes to a GPS, a faster port than
serial (RS232) is highly desirable. Since I no longer get paid to deal
with RS232 ports, and a GPS is a recreational device, I don't intend to
mess with the confusion, and grief of dealing with a serial configuration.



Your call.

Don't bother to take up surfing, either.

If you mean standing up on a stick in heavy waves, I can think of less
painful ways of offing myself.


But gee -- it just might be appropriate technology for those
of us who don't walk on water.

Are you implying that you use a surfboard for transportation?
Interesting concept. You must have a limited list of places to go.
I prefer a boat.

wrote:

On Tue, 31 Aug 2004 18:25:58 -0500, Ron Hunter
wrote:


wrote:


On Mon, 30 Aug 2004 21:02:08 -0500, Ron Hunter
wrote:



Mxsmanic wrote:



Ron Hunter writes:




And a keyboard is the only thing you have on a USB interface?


I have two devices on USB, because that's all they support. One of them
requires that it not share the interface with anything else, which
pretty much blows one of the major advantages touted for USB.

That's out of three computers, too. I have three devices on serial
ports. I have four devices connected via SCSI. I have two devices
connected via PS/2 interfaces.

The keyboard is not among the devices connected via USB, because I like
to keep things simple, and I prefer a keyboard that works no matter what
state the system is in.




It would take dozens of serial ports to equal the data
handling capacity of one USB 2.0 port.


I don't need the data-handling capacity of a USB 2.0 port for the
devices I have connected via serial ports.


No, but in order to transfer megabytes to a GPS, a faster port than
serial (RS232) is highly desirable. Since I no longer get paid to deal
with RS232 ports, and a GPS is a recreational device, I don't intend to
mess with the confusion, and grief of dealing with a serial configuration.



Your call.

Don't bother to take up surfing, either.

If you mean standing up on a stick in heavy waves, I can think of less
painful ways of offing myself.


But gee -- it just might be appropriate technology for those
of us who don't walk on water.

Are you implying that you use a surfboard for transportation?
Interesting concept. You must have a limited list of places to go.
I prefer a boat.

In article , Ron Hunter
writes
Prometheus wrote:

In article , Ron Hunter
writes


Fine, up the price $20 I will pay!
A lot of people will not.

That's why companies make more than one model of a device.

Indeed, the standard model with the standard serial interface and the
restricted model with only USB.
--
Ian G8ILZ

In article , Ron Hunter
writes
Prometheus wrote:

In article , Ron Hunter
writes


Fine, up the price $20 I will pay!
A lot of people will not.

That's why companies make more than one model of a device.

Indeed, the standard model with the standard serial interface and the
restricted model with only USB.
--
Ian G8ILZ

wrote:

On Tue, 31 Aug 2004 18:28:22 -0500, Ron Hunter
wrote:


wrote:


On Mon, 30 Aug 2004 21:09:54 -0500, Ron Hunter
wrote:



Mxsmanic wrote:



Jeremy Nixon writes:




The normal consumer doesn't buy GPS units because they're too complicated
and have things like serial ports.


The normal consumer doesn't buy GPS units because he has no use for
them.




Basically every normal consumer I know, apart from my parents, wants a
GPS unit but hasn't bought one because there isn't one made for them.
Myself included.


They just want gadgets. In that case, anything will do.




That's because the only ones they're buying are the ones installed in their
cars.


They aren't much use in the home, since homes hardly ever move.



I use mine on trips. Very handy, and I am never lost with it is with me.




It's hard to find a laptop these days that has one.


Ah, laptops. I wouldn't know, as I've never found a use for a laptop.



I have use for one, but the ease with which one can be stolen, or
damaged has deterred me from buying one.




Desktop computers aren't nearly as relevant since they're not portable.


I can't imagine anyone dragging a laptop around in any situation that
would justify a GPS for navigation.



If you choose to purchase your GPSR at a place like Office
Depot or Staples, you can go just a few aisles away and purchase a
stock of paper and pencils. They are entirely adequate for recording
coordinates if a laptop is not desirable. For simple navigation, you
don't need a laptop.


On a recent cruise I was carefully plotting the daily observations on a
map and measuring to see how far we were from various locations, and how
fast we were going (average). Then I went on a tour of the ship and
found that the computer that did the ship's navigation had a display I
could look at and find all that data displayed on a moving map. Kinda
made me feel silly.


I, on the other hand, don't feel at all silly that I can
extract a square root with paper and pencil. You'd be aghast at what I
made my kids do before I'd let them buy calculators in junior high.

Well, few people go to that kind of trouble now, but, yes, I do remember
the method. But I NEVER intend to do it that way again. Never used
caculators when I was in school. grin.


And if you really cozied up to the navigator on board, you'd
likely find he had his own personal GPSR, sextant and HO tables
squirreled away somewhere.


Oh, I am SURE he had all that since the law requires that non-electronic
navigation aids be onboard, and they must be used for periodic checks as
well. However, in cruising the inside passage in Alaska, navigation is
quite possible using the old 'mark one eyeball' most of the time. Now
keeping an 880 foot ship in the center of the waterway is another matter.




Huh? How about a person who does research on his ancestry and visits
cemetaries, and other places, like old homes? Being able to pinpoint a
grave is a very useful feature, if one needs to return to it, or
reference it for others.


Tell that to a normal, non-geek person.


They find that out for themselves.




And the average consumer doesn't *care* about the technical potential to
interoperate with anything given enough work.


A lot of GPS buyers are not average consumers.


True, and will remain true until GPS receivers become easier to use, and
getting rid of a complex and bothersome (and SLOW) RS232 serial port
sure would HELP.


Is Jeremy sharing his popsicle sticks with you?

Ron Hunter writes:

Except that Ethernet/USB connectors are standard, no buying an adapter
to make it fit the connector on the equipment, and require no tools to
attach it.

It is a great deal more difficult to write a driver for the operating
system of your choice to make a USB device work usefully (and thus you
end up beholden to your GPS provider for updates to track your OS).

In comparison, you can connect any standard-serial-interface GPS
device to something that is expecting it, and software support for
something that doesn't is relatively trivial.


Your comment about the mapping data transfer is completely spurious
becuase if you want an all-signin and all-dancing GPS that talks USB
map transfers to your computer, bully for you. If that GPS doesn't
*also* have a serial port that can deliver data to a device that
doesn't need to talk the hugely complex USB protocols, then that GPS
has been crippled.

And the reason it has been crippled is to appeal to the sort of people
who can't understand why a standard and easy-to-interface
communication standard is a good idea.

B