Magellan GPS - Mapping POI's to Autocad?

Author

Mapping POI's to Autocad?

circleb

2005-12-07, 5:49 pm

I use Autocad to map out well locations for our groundwater sampling
business and would like to use the Explorist 400 I received as a gift to
expedite the mapping. While onsite, it will replace the need for surveying
the locations but I'm not sure how to bring the location information (which
I saved as POI's) to Autocad. Any info on this is very appreciated, thanks.

Jack Erbes

2005-12-07, 5:49 pm

circleb wrote:

> I use Autocad to map out well locations for our groundwater sampling
> business and would like to use the Explorist 400 I received as a gift to
> expedite the mapping. While onsite, it will replace the need for surveying
> the locations but I'm not sure how to bring the location information (which
> I saved as POI's) to Autocad. Any info on this is very appreciated, thanks.

If you keep tracks and create waypoints (is that called a POI in the
eXplorist?) you can do some approximate or rough mapping of boundaries
and mark points. Those can be saved to the SD card and read on a PC
with Notepad or downloaded from the GPS with a utility like g7towin
(freeware)or GPS Utility (shareware, but a good program).

That will give you the data as ascii text data if you can import or
manipulate that. GPS Utility will also download and save waypoints and
tracks to a number of formats including *.dxf, Autocad should be able to
read *.dxf I think.

GPSU can also be used to display and edit the GPS data.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

circleb

2005-12-07, 5:49 pm

Yep, POI's are waypoints, apparently that term is new to the 400? Jack,
this looks like just what we need. It doesn't say it's known to work with
the Explorist 400, but hopefully it will, can't see why it wouldn't. Also,
gpsu's website, http://www.gpsu.co.uk/gpsrecs.html, says they also support
Google Earth, which we've been using at times as well, so it's possible
you've helped in 2 ways today. :-) Anyway, thanks a bunch for your fast
answer, you rock.

"Jack Erbes" <jackerbes@adelphia.net> wrote in message
news:s8ednRAzbtiLlAr
enZ2dnUVZ_v-dnZ2d@adelphia.com...
> circleb wrote:
>
>
> If you keep tracks and create waypoints (is that called a POI in the
> eXplorist?) you can do some approximate or rough mapping of boundaries and
> mark points. Those can be saved to the SD card and read on a PC with
> Notepad or downloaded from the GPS with a utility like g7towin
> (freeware)or GPS Utility (shareware, but a good program).
>
> That will give you the data as ascii text data if you can import or
> manipulate that. GPS Utility will also download and save waypoints and
> tracks to a number of formats including *.dxf, Autocad should be able to
> read *.dxf I think.
>
> GPSU can also be used to display and edit the GPS data.
>
> Jack
>
> --
> Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
> (also receiving email at jacker at midmaine.com)

Jack Erbes

2005-12-07, 5:49 pm

circleb wrote:

> Yep, POI's are waypoints, apparently that term is new to the 400? Jack,
> this looks like just what we need. It doesn't say it's known to work with
> the Explorist 400, but hopefully it will, can't see why it wouldn't. Also,
> gpsu's website, http://www.gpsu.co.uk/gpsrecs.html, says they also support
> Google Earth, which we've been using at times as well, so it's possible
> you've helped in 2 ways today. :-) Anyway, thanks a bunch for your fast
> answer, you rock.

You're welcome. But, post facto, I better tell you that I have not used
an eXplorist and may have made some bad assumptions.

I just read the online manual for the 400 and see that the memory in
that unit and the SD card in it are seen as a removable drive or files
and folders under Windows. That sounds good and easy enough to deal
with but it raises some questions about using GPSU.

I use GPSU with the Meridian series and older units that have RS-232
serial ports. GPSU finds the COM port and the GPS there. On the newer
computers without hardware serial ports I use a serial to USB adapter,
that creates a virtual COM port, and GPSU uses that.

But the eXplorist 400 will not have a COM port so you probably won't be
able to interface directly to the eXplorist 400.

But you can still use the trial version of GPSU to see if it is going to
work for you. GPSU should be able to see and read the waypoint, route,
and track files on the 400 (they are ascii text files).

If you download file from the 400 and can't convert it to a *.dxf file
with the trial version, email it to me and I'll convert it and send it
back to you so you can test one.

Let me know how that works out and my apologies if I mislead you any.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

seanb@susqtech.com

2005-12-11, 5:48 pm

I have the Explorist 400. I see a lot of talk about manipulating the
ASCII text file and how easy it is. My problem is - once I open the
ASCII text file (say a POI file) I don't know what each 'column'
(if you will) in the entry represents. I can identify the long/lat
just fine. Here's a sample entry out of my POI file:

$PMGNWPL,3908.628,N,07809. 055,W,0000213,M,Work
,,a*2A

There appears to be 10 items delimited by commas. I know what items
1-5 are, and also item 8 is clearly the name I gave this POI. What are
the remaining items? Is item 6 elevation? What's the 'M' in
item position 7? What's the 'a*2A' in item 10 position?

Anyone know?

Thanks,
-sean

Jack Erbes wrote:
> circleb wrote:
>
>
> If you keep tracks and create waypoints (is that called a POI in the
> eXplorist?) you can do some approximate or rough mapping of boundaries
> and mark points. Those can be saved to the SD card and read on a PC
> with Notepad or downloaded from the GPS with a utility like g7towin
> (freeware)or GPS Utility (shareware, but a good program).
>
> That will give you the data as ascii text data if you can import or
> manipulate that. GPS Utility will also download and save waypoints and
> tracks to a number of formats including *.dxf, Autocad should be able to
> read *.dxf I think.
>
> GPSU can also be used to display and edit the GPS data.
>
> Jack
>
> --
> Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
> (also receiving email at jacker at midmaine.com)

Jack Erbes

2005-12-11, 5:49 pm

seanb@susqtech.com wrote:

> I have the Explorist 400. I see a lot of talk about manipulating the
> ASCII text file and how easy it is. My problem is - once I open the
> ASCII text file (say a POI file) I don't know what each 'column'
> (if you will) in the entry represents. I can identify the long/lat
> just fine. Here's a sample entry out of my POI file:
>
> $PMGNWPL,3908.628,N,07809. 055,W,0000213,M,Work
,,a*2A
>
> There appears to be 10 items delimited by commas. I know what items
> 1-5 are, and also item 8 is clearly the name I gave this POI. What are
> the remaining items? Is item 6 elevation? What's the 'M' in
> item position 7? What's the 'a*2A' in item 10 position?
>
> Anyone know?

You bet! Here is a link to get you start on NMEA sentences:

http://www.gpsinformation.org/dale/nmea.htm

Welcome to the Learning Curve on what might turn out to be a mildly
addictive hobby!

Looking at the last three letters in the identifier for now (....WPL),
that is a waypoint data sentence, a standard NMEA WPL sentence breaks
down as per this example from the link above.

$GPWPL,4807.038,N,01131.000,E,WPTNME*5C

WPL Waypoint Location
4807.038,N Latitude
01131.000,E Longitude
WPTNME Waypoint Name
*5C The checksum data, always begins with *

As you've noted above, your sentence contains two additional bits of
info. That is because it is Magellan's proprietary version of the NMEA
standard WPL sentence and contains some additional info.

I think the info on decoding the Magellan sentences is in your manual,
if not it should be found at places like

http://www.gpsinformation.org/

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

Ralph

2005-12-12, 5:49 pm

Got this info from this URL:

http://www.gpsinformation.org/mag-proto-2-11.doc

PMGNWPL

This message is used to transmit waypoint information. It is based
upon the NMEA 0183 WPL message with the addition of altitude, message
and icon information fields. An example of this message is given
below:

$PMGNWPL,llll.lll,N,lllll.lll,W,aaaa,F,c----c,c---c,c=E2=80"c,xx*hh<CR><LF>

The first field consists of two digits representing the degrees of
Latitude, with a leading zero if necessary, followed by two digits
representing the minutes of Latitude, with a leading zero if necessary,
followed by fractional minutes. For example, a latitude of 38=C2=B0
15=E2=80=99 30=E2=80=9D would be encoded as 3815.5. The next field
consists of either the letter =E2=80=9CN=E2=80=9D or =E2=80=9CS=E2=80=9D to
indicate North or South Latitude. The next field consists of the
Longitude formatted like the Latitude, but with 3 digits to represent
the degrees of Longitude. For example, a Longitude of 118=C2=B0
5=E2=80=99 15=E2=80=9D would be encoded as 11805.25. This field is
followed by an =E2=80=9CE=E2=80=9D or =E2=80=9CW=E2=80=9D to indicate East =
or
West Longitude. The next field is the Altitude, followed by its units
(=E2=80=9CF=E2=80=9D
for feet, =E2=80=9CM=E2=80=9D for meters). Three text
fields follow the position, the first is the name of the waypoint, the
next is a message or comment for this way point, and the last is an
Icon identifier. Some GPS receivers do not support messages or icons.
In this case these fields are not sent by the unit and ignored if
received by the unit. Currently, a blank icon field indicates a
default icon. Magellan Products use lower case to indicate which icon
is associated with the waypoint. See the icon appendix for details.
The final data field is a waypoint type indicator (a numerical value
particular to a given model of GPS units) which is used in some GPS
units. Trailing fields need not be transmitted if they are empty.

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