GPS HOWTO posted

[thoughtfix]

Enjoy!
http://thoughtfix.blogspot.com/2006/02/howto-bluetooth-gps-and-gpsdrive-on.html

Lots of pictures.

Quick run to the conclusion:
GPSDrive would be fun for camping, off-roading, or long road trips but it's not meant for city navigation.

[gnuite]

I've been working with the iBlue receiver and the gpsdrive software myself. My conclusion is similar to thoughtfix's. The hardware works fine (though not as sensitive as prior reviews had indicated - I have an external antenna on order). The software, however, is in need of major work. With a boatload of modification, I got the gpsfetchmap.pl script to download my area's google maps images (street maps, not satellite), but there is still not sense of turn-by-turn directions, and according to some newsgroup posts, there is no plan for turn-by-turn directions, since there is no open-source data.

Still, it's a lot of fun to watch yourself drive along the road on the map. If nothing else, you'll at least know what roads are around you.

And yeah, what's up with that wasted white space? I'm gonna hack at the code and see if I can remove not only that extra space but the map/menu/status tabs, which waste 15 pixels of the top part of the screen - I'll try relocating them to the menu.

And the +/- buttons on the Nokia 770 should be involved in some zooming (maybe map scale switching, I'll take a look...).

[thoughtfix]

It would be nice for someone like my boss who does a lot of offroading though. His handheld GPS does route tracking but it doesn't show topographical maps.

I didn't try topo maps yet - no need in this city!

[mccake]

I suppose the maps need to be downloaded onto the 770 before the start of your trip. Where will the maps be stored? on the MMC? cuz I think the maps will take quite a lot of memory.

[Chainsaw76]

If you change the rfcomm channel number in the startuo scrip you can download maps as you need them.

The location of the maps is editable in gpsdrive. I have mine stored in a subdirectory on the MMC card.

-Jason

[gnuite]

I suppose the maps need to be downloaded onto the 770 before the start of your trip. Where will the maps be stored? on the MMC? cuz I think the maps will take quite a lot of memory.

The maps are stored in whatever format the nokia supports (.gif, .png, .jpeg, etc.). In my case (google street maps in PNG-8 format), each 1280x1024 map is between 273 bytes (all one color, like water or empty fields) and 200k (dense inner city). So, average map size depends on the street density of the area you want to cover.

As a real example, I currently have 195 maps on my device right now (on the included MMC), and they take up 28 megabytes. The 195 maps are sufficient to cover a rectangle on the order of magnitude of 10000 square kilometers of dense suburbia in google's 3rd-most-detailed scale (very readable, includes most street names, see google maps for an example). I'm currently waiting for my 1GB expansion card to arrive so that I can install the entire Washington/Baltimore area (including suburbs) in the same scale, which I downloaded yesterday, 2850 maps, about 250 MB. Then I'm going to be retrieving the rest of the U.S. in a higher (less detailed) scale. I don't plan on using the card for anything big (like music or movies), so I'll be dedicating it mostly to maps.

Topographical maps will probably use more space, since they compress less. The cvs version of gpsdrive includes a gpsfetchmap.pl program to fetch all of the google satellite images in a specified area. I personally prefer the street maps, for both space and readability reasons (I like knowing which road I'm on). If I could get the hybrid maps on gpsdrive, that would be awesome, but I think it would require some overlaying of the street maps on top of the sat maps, perhaps with some alpha blending (like Google Maps/Earth does).

[thoughtfix]

If you change the rfcomm channel number in the startuo scrip you can download maps as you need them.

The location of the maps is editable in gpsdrive. I have mine stored in a subdirectory on the MMC card.

-Jason

I got the channel changing to work on your advice, Chainsaw76, but didn't include that in this HOWTO. I figured it was running long enough :)

[thoughtfix]

Even without street-level navigation, I still can't wait for the next, more polished version of GPSDrive on maemo. :)

[gnuite]

Even without street-level navigation, I still can't wait for the next, more polished version of GPSDrive on maemo. :)

In the meantime, you can use waypoints to simulate street-level navigation. I wrote a script to convert Google Maps Driving Directions to a gpsdrive-compatible waypoints file (http://www.gnuite.com/cgi-bin/way.txt). Just give the script your source and destination, and it returns a text/plain that you can save as way.txt for gps-drive. The script is even named way.txt to avoid having to tap a name on your Nokia 770.

Use case is relatively simple: go to http://www.gnuite.com/cgi-bin/way.txt on your Nokia 770, tap in your source and destination (or select prior locations, if you have cookies enabled), then submit. A bunch of text numbers will appear. If they look sensical (e.g. lats and lons of magnitude less than 360), use "Save as..." and save to your desired location. To make this part easier, I save in the Documents directory and create a link from $HOME/.gpsdrive/way.txt to $HOME/MyDocs/.documents/way.txt, or you can just tell gpsdrive to look in your Documents directory. In any case, the next step is to start up gpsdrive and use the "Find..." button to create a Route from all the waypoints in way.txt.

Voila, instant super-accurate driving directions. Just follow the blue dotted line, it's even easier than printed Google Maps directions. Yes, there are a lot of generated waypoints, at the way, but at least the dotted line is smooth and accurate.

[mccake]

I'm really interested to get a gps device as I travel a lot around europe. However, before I get the iBlue device, is it possible for me to gpsdrive as a map reader? Seems that it's possible. However, I did try it out but I'm kinda lost by the setup as the application is not so smooth for now.

[penguinbait]

What type of hardware are you using? I am assuming BT? I already have a nice garmin, with a serial cable. Does anyone know of any serial to miniusb cable that does not require power. I don't think power should be needed, as the GPS is already putting out NMEA data. And from my understanding the miniusb is already setup as serial right? any cable masters out here?

[Supergeek]

If that would work, I could try to make my own cable. I just assumed it would have to be powered.

I've got a Garmin eTrex with serial cable.

[thoughtfix]

Hmm ... I ASSUME the USB host mode will support USB->Serial adapters but the set-up would be messy. It'd go:

Nokia tablet -> USB Cable -> USB power injector box -> USB to Serial adapter -> Serial cable -> GPS

[thoughtfix]

What type of hardware are you using? I am assuming BT?

Yes- it was all Bluetooth.

[chrwei]

I got the gpsfetchmap.pl script to download my area's google maps images (street maps, not satellite)

are your changes published somewhere?

[penguinbait]

I wouldn't think it would need power, as it is already powered and putting out the data on the serial line. But I am not sure, I am clueless, it just seems like it would work???

[gnuite]

are your changes published somewhere?

Not yet... I basically hacked the old script so much that it no longer works with the original expedia source. (Sounds hard to believe, but I wanted to set up the maps so that they overlapped by exactly one google tile horizontally and vertically, so I replaced the whole "get maps from the following lat/lons" idea to "get all tiles between these two lat/lons and tile them together so that they overlap by 1 tile".)

I guess I can clean it up and maybe publish it if anyone is interested (sounds like at one person is), but by that point it will support only Google Maps' street maps (no topo), so I'll probably rename it to gpsfetchgmap.pl or something.

[gnuite]

Voila, instant super-accurate driving directions. Just follow the blue dotted line, it's even easier than printed Google Maps directions. Yes, there are a lot of generated waypoints, at the way, but at least the dotted line is smooth and accurate.

The sheer number of waypoints that my script was generating (almost 40,000 waypoints to go from San Francisco to New York???) prompted me to add some Douglas-Peucker simplification code. You can now specify the desired tolerance on the form. 0.00005 cuts the number of waypoints by 60-80%, but still looks pretty good and is very useful for local applications. Specify a higher tolerance to cut down the number of waypoints even more.

Here are some sample tolerances and results for the San Fran -> New York case:
0.00000 36812 waypoints
0.00001 18337 waypoints
0.00002 12747 waypoints
0.00005 7865 waypoints
0.00010 5569 waypoints
0.00025 3494 waypoints

[RogerS]

In the meantime, you can use waypoints to simulate street-level navigation. I wrote a script to convert Google Maps Driving Directions to a gpsdrive-compatible waypoints file. ...

Voila, instant super-accurate driving directions. Just follow the blue dotted line, it's even easier than printed Google Maps directions. Yes, there are a lot of generated waypoints, at the way, but at least the dotted line is smooth and accurate.Can you post a screen capture to show us what this looks like?

Sounds, well, awesome. But I will not be getting GPS for a while yet, so I'll have to make do with what you describe and what you show.

[ercanmetin]

I got iblue gps last week, and just because maps had to be downloaded via cellular connection was a little annoying since we still don't have HSPDA and NokiaN95 around :)

Anyway, I saw your post Gnuite, I want to do the exact same thing, I have a network drive at home, which I connect my N770 thru ftp, so I'm not using any space on my 1gb MMC! I want to dedicate maybe 300 - 400 megs just for maps, I want to download them and never worry about downloading them again...

But I have questions, when I download a map, I believe it's in specific zoom so I have to download same area with different zoom levels?
Just because I might need to zoom them one day ?
and where do I save these maps exactly, I believe they have to be folderized with their zoom levels, and stuff?

And one last thing where do I download them? (exact link here pls)
I download them using pc? and dump them to MMC?
or I download them VIA Maemo mapper ? But I believe when you download them via mapper they are in cache for a while and then gone?

I would really apriciate if you step thru this process...

Thanks in advance...






The maps are stored in whatever format the nokia supports (.gif, .png, .jpeg, etc.). In my case (google street maps in PNG-8 format), each 1280x1024 map is between 273 bytes (all one color, like water or empty fields) and 200k (dense inner city). So, average map size depends on the street density of the area you want to cover.

As a real example, I currently have 195 maps on my device right now (on the included MMC), and they take up 28 megabytes. The 195 maps are sufficient to cover a rectangle on the order of magnitude of 10000 square kilometers of dense suburbia in google's 3rd-most-detailed scale (very readable, includes most street names, see google maps for an example). I'm currently waiting for my 1GB expansion card to arrive so that I can install the entire Washington/Baltimore area (including suburbs) in the same scale, which I downloaded yesterday, 2850 maps, about 250 MB. Then I'm going to be retrieving the rest of the U.S. in a higher (less detailed) scale. I don't plan on using the card for anything big (like music or movies), so I'll be dedicating it mostly to maps.

Topographical maps will probably use more space, since they compress less. The cvs version of gpsdrive includes a gpsfetchmap.pl program to fetch all of the google satellite images in a specified area. I personally prefer the street maps, for both space and readability reasons (I like knowing which road I'm on). If I could get the hybrid maps on gpsdrive, that would be awesome, but I think it would require some overlaying of the street maps on top of the sat maps, perhaps with some alpha blending (like Google Maps/Earth does).

[aleksandyr]

Maemo mapper does not delete maps, IIRC. They're saved to whatever cache directory you specify. Use Download Area, Download Along Route, and Auto-Download to load them.

Yes, you need separate maps for separate zoom levels, although maemo mapper will interpolate/resize.

It should just handle map downloading automatically with the proper options. Limitations of non-vector maps aside, it's a VERY slick program.