Position on Map - GPS

[Bruce Fox]

Hey guys,

I have successfully interfaced to my GPS, and extracting Lat/Long etc.

My next phase is to introduce a scanned .bmp Map into the app.

I'm seeking anyones advice who may have done this or has any
words of wisdom.

I'm anticipating palcing the .bmp into a picture control. The size
of which is determined by the scan size of the .bmp.
This area (of the .bmp) will consist of (screen) co-ordinates like,
(0,0) for top Left, (0, ?) for top Right, (?,0) for bottom Left, and
(?,?) for bottom right.

Then I can 'set (calibrate)' the position of say (0,0) to a known
Lat/Long position (read from the Map), and do the same with at
least 2 other co-ordinates.


Cheers,
Bruce.

[crpietschmann]

I think that you would have to have point on the map that are actual coordinates and then do some math to figure where on the map the coordinates from the GPS are.
That would probably work better.

[Bruce Fox]

Originally posted by crpietschmann
I think that you would have to have point on the map that are actual coordinates and then do some math to figure where on the map the coordinates from the GPS are.
That would probably work better.

yep, thems what I'm thinking

[ae_jester]

Is this for a wireless handheld device? Cuz I'm going to be creating something very similar over the coming months.

[Bruce Fox]

Originally posted by ae_jester
Is this for a wireless handheld device? Cuz I'm going to be creating something very similar over the coming months.

Possibly.

I'm just putting something together for my laptop, then
get into Windows CE (iPAQ) embedded Visual Basic.
I'ts comming together well, the inteface to the Magellan was
simple.... Once I placed the bloody thing in the right NMEA mode

It outputs contiuous streams of NMEA Sentances. No need for
handsaking


There are Comercial apps out there for iPAQ etc an PC's. However, I dont need all the overhead etc that comes with those
apps.

[ongtw]

sorry but i will not offer any help as i dunno what you guys are talking about. but bruce, your program sounds interesting.. any pointers for me on the project you're working on?? how do you interface with GPS? i haven't got the slightest clue

[Bruce Fox]

Originally posted by ongtw
bruce, your program sounds interesting.. any pointers for me on the project you're working on?? how do you interface with GPS? i haven't got the slightest clue

I am using the MSCOMM (that comes with VB6).

Connect ur GPS via RS-232 Serial cable to ur PC, open the apropriate
port (using MSCOMM), and wamo - ur done

With the GPS I have, u can send / receive Waypoint, Track data
etc. This is done with no NMEA mode (on the GPS) selected.
However, I'm using the GPS in a NMEA Mode that provides a
continuos stream of (serial) data. I'll split up that data stream
into Lat/Long (and UTC) components, and display a cursor
on a map at that location

[Bruce Fox]

Ok, making progress, however before I get to far with the math
calcs, what (if any) settings should I use. ie

a. Twips v pixels, (maybe pixels for future API use?)
b. Scale Modes

Anything like that.

Cheers,
Bruce.

[lerouxc1]

I have all this code written already...I don't have it now, but will post later today. Or contact me view email [email protected]

I have a program which plots data on a bmp. It uses an error correcting algorithm which I designed to correct for coordinate systems that aren't exactly square. (Like on satellite imagery)
Works very well. I have used this program to plot data in real time while I was driving. I have also used this program to plot previously recorded data.

I also have created an OCX control which connects to GPS units through comm port. Simply drop onto your form! The sentenceArrival event is raised when new data has arrived. You can read the sentence as it arrived, or access individual fields such as lat, long, speed, heading, etc.

Still somewhat under construction, but it could save you lots of time. It is functional, but support for some NMEA and Garmin sentences is not yet implemented, such as satellites in view, and waypoint stuff.

Sorry I can't post the code now...I'm at work.

[plenderj]

Pixels pixels pixels all the way

[lerouxc1]

This software is functional, but by no means finished.
It should give you all the stuff you need. I'm going to start a new version soon. (I didn't finish this one because I decided to change the architecture)

Code is attached. Also, the executable should run with the attached image, data file, and configuration file. Unzip to a folder and run the executable, then select Plot Trip from Tools menu, select the .gps file and watch!

Download here

[lerouxc1]

Here's the OCX control that I created.
As I said before, support for some NMEA and Garmin sentences has not yet been implemented.

This thing is cool, cuz you can just add it to your project, and all the sentence parsing etc. is already done!!

download here


I've seen something similar to this going for $150 on the net!!!!

Please give feedback!
Enjoy

[Bruce Fox]

crpietschmann, Jamie and lerouxc1,
Thanks for you comments.

lerouxc1 I'll definitly have a good look at those examples/codes.
Thanks for that

I have just about finished, I'm implimenting Lat/Long conversion
to get all values to one type (ie decimal nautical miles), to enable
positioning data etc.

Thanks again lerouxc1 - I'll post feedback


Cheers,
Bruce.

[plenderj]

Originally posted by Bruce Fox
crpietschmann, Jamie and lerouxc1,
Thanks for you comments.

lerouxc1 I'll definitly have a good look at those examples/codes.
Thanks for that

I have just about finished, I'm implimenting Lat/Long conversion
to get all values to one type (ie decimal nautical miles), to enable
positioning data etc.

Thanks again lerouxc1 - I'll post feedback


Cheers,
Bruce.

]

This sounds pretty damn cool man!

[wossname]

I was doing this recently but I went for the whole handshaking protocol. The handshaking for a Garmin GPS device is a complete nightmare. Talk about overkill.

Anyway I might just try the one-way text output like bruce did. First thing I'll do is create an onscreen realtime compass on my laptop, fullscreen!! I'll be doing it in VB.Net though.

[DaveBo]

I would think scale mode would make life much easier.
Couldn't you set the scale to approximate lat/lon coords?

Just might have to convert degrees,minutes,seconds into a real number,
e.g. 50 30 00 = 50.5

Sounds like fun, DaveBo (I have both Garmin & Magellan handhelds)

[Bruce Fox]

Wow, this is old...

Annyways, It has been extreamly successful. I scan a chart, calibrate it (3 points) and store the calibration data at the head of the scanned image jpg and save that as a custom file type. Later, when the chart is selected for loading I strip off the calibration data and then I am left with the jpg image data which gets loaded into a picturebox. As the mouse moves over the chart, the Lat/Long values are displayed in a statusbar.

Parsing the NMEA was simple enough, then it was just a matter of converting that data.

My GPS data then provides point track info to move a symbol (aircraft) over the charrt as required.




Bruce.

[Bruce Fox]

Anyway I might just try the one-way text output like bruce did.

Yeh, for this type of application it makes sense. On the other hand, if your developing a desktop 'waypoint'/'route planner' you would need to go both ways.




Bruce.

[kaddour]

!!Urgent...Urgent...Urgent...Urgent...Urgent...Urgent...

Hi Guys,
The software downloads posted by lerouxc1 above are not working (his email as well)...
Can someone send them to me please. I need help in building my GPS tracking application...

Many thanks....
Kaddour

[Bruce Fox]

What parts do you need?

I don't have his ocx anymore, but what I wrote at the time I have tucked away somewhere.

[kaddour]

Thanks Bruce Fox for your reply.
I need the mapping bit, please - thanks - Kad

[h_1985]

Hello,"Bruce Fox" please upload the files of "lerouxc1" again
i need them plz

[Bruce Fox]

Hello,"Bruce Fox" please upload the files of "lerouxc1" again
i need them plz

Like I said, I don't have them anymore.

I had completly written my app from scratch and it worked quite well.
It was a long time ago.....

I had described how I did it at the time, and it functioned as expected.
Once I loaded the scanned Map, I then calibrated it at three points.
The calibration data was stored in the first 100 bytes of a file that also contained the bitmap Map (this is the Calibrated Map).
When loaded, the first 100 bytes were read and held as calibration data, the remaining bytes were the bitmap which was extracted to a temp file prior to loading
into the PictureBox.


Bruce.