Re: Maemo Mapper: GPS for the Nokia 770
 

Actually, I just found (and fixed) another possible cause of trailing gibberish, so even if the problem was recent, try again and see if it is now fixed.

Re: Maemo Mapper: GPS for the Nokia 770
 

Dear All,
I am a complete and total NOOB...I have not even received shipment of my Nokia 770 yet. So, please cut me some slack.

I am interested in using the 770 as a GPS device in my car. I have read lots of info online about Maemo Mapper and Bluetooth GPS receivers. Yet, I have not found the answer to a simple question: Does one have to be connected to the internet in order for the the 770 to function like an off the shelf GPS device (like a Garmin or Tom Tom)? It seems to me that this would be a ridiculous limitation if it is so! Is it so?

Thank you in advance for your replies,
Neil:confused:

Re: Maemo Mapper: GPS for the Nokia 770
 

nspeer,
No, you don't need to be connected. You just need to download the maps for the area you'll be driving in, in the zoom levels you're interested in.

Re: Maemo Mapper: GPS for the Nokia 770
 

Pre-download that is...

Re: Maemo Mapper: GPS for the Nokia 770
 

To clarify the previous answers a little bit, you can think of Maemo Mapper as able to run in two different modes: with Auto-Download enabled or disabled.

With Auto-Download disabled, then before you embark on a trip, you must download all maps that you anticipate needing for that trip. There are two ways to do this: with an external program like winmapper, and with the "Manage Maps..." menu item in Maemo Mapper itself.

In the case of the latter, you have two options. You can download maps "by area," in which case you provide the latitude/longitude of the corners of a rectangular area, and Maemo Mapper will download all of the maps in that rectangle. Or, you can download maps "Along Route", which means that, if you have a route loaded (i.e. directions to a location), then you can download all of the maps that you would need along that route.

With a large enough memory card, you can conceivably store entire countries at a decent resolution. To maximize the effectiveness of your memory card, though, I recommend downloading maps around your home at a high resolution, and downloading maps further away from you at a lower resolution.

With smaller memory cards, it probably makes more sense to just plan each trip in advance and use the "Download by Route" feature. This will minimize the amount of memory card space needed at one time, but it reduces flexibility because you won't have map data for areas outside of your route. When you are done with your route, you can delete all your maps to save space and/or prepare for the next trip.

With Auto-Download enabled, Maemo Mapper will download maps on-the-fly as needed. This eliminates the need to pre-download large areas of maps, but it requires an active internet connection at all times. If you're using Maemo Mapper in the car, that usually means connection to a cellular service with a data plan. Note that Maemo Mapper will still cache the downloaded maps for you, to minimize internet access, so if you want to keep your memory card free of excess maps, you may want to clean out your Map Cache every once in a while.

I'm sorry it's not more intuitive. This app is in serious need of documentation! But I hope this helps.

Re: Maemo Mapper: GPS for the Nokia 770
 

Gnuite,
Thank you so very much for taking the time to elaborate on the Maemo Mapper app. I really appreciate it! Please permit me to ask further:

Approximately how much memory will be required for a reasonably detailed map of the Denver, CO area (for example)? I don't need the whole state, just Denver and it's surrounding area. Will I need to purchase an addtional RS-MMC for that?

Will the 770 with Maemo Mapper function like an off the shelf GPS device (like a TomTom or Garmin)? That is, will it display directional arrows indicating when and where to make a turn? Will it give voice directed turn-by-turn directions? Will it show on the map an icon pinpointing my current location (car)?

Thanks,
Neil

Re: Maemo Mapper: GPS for the Nokia 770
 

When I was trying to do Denver and the outlying areas (up to ft collins, down to castle rock), it looked like it would take around 550mb to do zoom levels 2-10. It would be around 2gb if I included level 1. Unfortunately I haven't successfully downloaded all the maps with my n800.

Re: Maemo Mapper: GPS for the Nokia 770
 

Do you need the full range of zoom levels? I find 1 & 2 is good enough for me when I'm close to my destination, but outside that 4 & 5 is good enough for me. I don't normally download the other levels. Downloading all maps between 2-10 seems like you are downloading more maps then you may use, but to each there own as the saying goes.

Re: Maemo Mapper: GPS for the Nokia 770
 

This is a great point of reference. However (and this is purely personal preference), if you want to save space, you can skip the odd zoom levels and only use the even ones. You don't lose a lot of detail, and Maemo Mapper will still work at the odd zoom levels - it will just do a manual zoom of the next-higher level.

For example, the following sample setup for a city on the Eastern U.S. Seaboard should easily fit on a 1GB memory card (rough-order-of-magnitude square kilometers in parentheses):

Level 0: 10-km square around your house (100).
Level 2: Metro area of nearest city (1000).
Level 4: Metro + Suburbs of nearest city (10,000).
Level 6: Area surrounding the nearest few big cities (100,000).
Level 8: Eastern Seaboard, or maybe even everything east of the mississippi (1,000,000).
Level 10: Entire United States (10,000,000).
Level 12, 14, 16: Entire World (purely for showing off, e.g. "I can zoom out and see the whole world!) (500,000,000).

If you want to put more effort into it, you can download Level 6 detail for all major cities without too much trouble. This would be enough to drive through or around those cities using major highways. Rural areas, though, tend to have maps that compress better (more open space), so it's not a complete loss to keep maps of rural areas.

Zoom levels are roughly quadratically related to disk space. Each zoom level is exactly half the scale of the next-higher-resolution zoom level. 1 is half the scale of 0; 2 is half the scale of 1; etc. For a rectangular area, then, zoom level 1 takes up about 1/4 as much space as zoom level 0. Skipping every other zoom level saves you about 50%, as does removing your smallest-scale zoom level (assuming you have all the other zoom levels). Doing both doubles the savings! In other words:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16
2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16
2, 4, 6, 8, 10, 12, 14, 16
4, 6, 8, 10, 12, 14, 16

Each of those lines, except for the last line, takes up about half as much disk space as the previous line. The last line takes up about 1/4 as much disk space as the second-to-last line.

One last thing to consider: using Maemo Mapper with FAT16 will be very wasteful due to the internal fragmentation. Block sizes in FAT16 are 16 kB, so even the small maps (the smallest are about 100 bytes) will take up 16 kB. With FAT32, you can set the block size to as low as 512 bytes, which is fine for typically sized memory cards (it only becomes a problem for large hard drives) and will save you a lot of space.

Maybe someday I'll consider replacing the file-system back end with a sqlite database, but something tells me that will be very CPU-inefficient. Plus it would completely break everyone's map caches! :)

Re: Maemo Mapper: GPS for the Nokia 770
 

Your current location (assuming you have a GPS receiver) is plotted on the map. If you enable "Auto-Center", then the map will be panned automatically to follow your position. Or, you can use the stylus to point to a location on the map on which you would like to center the display. As you move, a red "track" is left behind you, telling you where you have been. You can clear this track at any time, or you can save it to a file, or load a track from a file.

Akin to tracks are "routes", which are green lines that usually describe where you want to go. You can download routes from anywhere to anywhere else, using latitude/longitude or standard addresses (e.g. "123 Main Street, 51122" or "5th Street and Broad Street, New York City, NY"), but you have to be connected to the internet. These routes, however, can be saved as GPX files and opened later. Many routes can be opened or downloaded, one after the other, and Maemo Mapper will lead you through all of them, consecutively.

The routes are downloaded from GPX Driving Directions Web Service, which is a regular web page, so alternatively you can use the Nokia 770/n800's web browser and save files from that page, or you can use a PC and save route files that you can then transfer to your Nokia device.

Once you have downloaded a route, Maemo Mapper will plot the route on the map, and if your route data has waypoints with descriptions in them (as do the routes from the above web service), then as you approach a waypoint, Maemo Mapper will pop up a message telling you what to do next (e.g. "Turn left at Freemont Avenue."). If you install flite and enable it in Maemo Mapper, then it will also speak the directions to you, just like an expensive in-car navigation system.

If you have a cell phone with data service, you can download a route from your current location to your destinatation in such a way that, if you get off track, it automatically re-downloads a new, re-calculated route, just like in-car navigation systems.

So many features and quirks... I really need to write them all down in some sort of documentation page. Lazy me!

Re: Maemo Mapper: GPS for the Nokia 770
 

How about something less ambitious, like aggregating the 256x256 map tiles into (for example) 1024x1024 units for storage and retrieval? Sure, there would still be some wastage for featureless regions (ocean, ice cap, etc.) but wherever detail exists, the larger tiles will better match the cluster granularity. Converting an existing map cache would be a fairly simple programming exercise, no? Maybe the "supertile" size becomes user configurable, once the code is in place.

Consider that even with FAT32, 2GB is the largest partition that will accept 512 byte clusters. The minimum becomes 1024 bytes at 4GB, 2048 at 8 GB, and so on. At the 32GB upper bound for SDHC, we're back to 8KB. So higher densities will take away nearly as much as they give, in this case.

Re: Maemo Mapper: GPS for the Nokia 770
 

Ahhh, I see now. So, if I read right, if one needs driving directions from Point A to Point B, one must have already downloaded this route and saved it on the Nokia 770 (assuming no internet connection once in the car). If not, entering point B's address into Maemo Mapper will not produce driving directions. Correct? So (if not connected to the net once in the car) one cannot just jump into the car and enter a destination and then receive driving directions to the destination. Is that correct?

thanks,
Neil

Re: Maemo Mapper: GPS for the Nokia 770
 

Yes, that is correct. Because Maemo Mapper doesn't actually have Navtec-like street data (due to license costs and space constraints), Maemo Mapper cannot itself calculate directions between two points. It outsources that processing to machines much larger than a Nokia 770/n800.

Re: Maemo Mapper: GPS for the Nokia 770
 

You mean like GPSDrive? Yeah, I thought about keeping GPSDrive's original 1024x1024 (or was it 1280x1024?) tile size, but downloading maps 256x256 at a time and storing them 1024x1024 at a time introduces complexities that increase both the CPU and memory requirements:

1. 1024x1024 tile size means that, although fewer tiles are loaded in order to draw the full 800x480 screen (up to 4 tiles instead of up to 12), each of those tiles is 16 times larger. The net difference is that I'd have to read 4.2 million pixels instead of 0.8 million. The amount of memory required to keep those pixels in memory also means a larger memory footprint (unless you want me to re-parse those mostly-same 6.3 million pixels every time the map is panned even a slight bit).

2. There would be two possible paths for retrieving an image: either directly from disk (1024x1024) or instead from HTTP. Two separate paths introduces additional complexity and thus increased CPU usage (and bugs). This isn't that big of a deal, until you consider the HTTP path on its own, which leads to #3.

3. In the case of HTTP, currently, Maemo Mapper uses libcurl to directly transfer the files from remote location to memory card. In order to store 1024x1024 tiles, Maemo Mapper would instead have to read and interpret the 256x256 PNG (or JPEG) data in-memory, then stitch the 256x256 tiles together, then write the data to memory card. This process is not only CPU and memory intensive, it reduces the quality of the original images because they are re-compressed using a lossy compression algorithm.

No, if I'm going to conglomerate multiple 256x256 tiles into a larger file, I might as well go the whole 9 yards and put them all into the same file.

That said, jpj, I appreciate your line of thinking. Your suggestion was good in theory, good enough for me to have considered it long and hard myself, but it doesn't work well with the way Maemo Mapper is implemented). And now, you'll have to excuse me as I go off on one of my typical little tangents (some would call them rants). The following comments are rather unrelated to your suggestion, so please don't consider it any form of disrespect toward you. (And while we're at it, don't consider any of my preceding rebuttal as disrespect, either. :))

The whole reason I started writing Maemo Mapper was because GPSDrive was extremely inefficient with CPU and memory, especially on the Nokia 770's limited hardware. Let's face it, GPSDrive was designed for the desktop, and on that platform, it is very versatile. On Maemo, however, you could not even start GPS Drive if you had any other applications open.

I have tried pretty hard to make Maemo Mapper as CPU- and memory-efficient as possible, to the point where some of my optimizations would not work as well for a different screen resolutions or for different behaviors (e.g. smooth tap-and-drag panning). Yeah, it's the classic "optimize before you even know you need it" blunder, but after seeing GPSDrive struggle so hard, I thought I'd address the performance issues first and foremost.

And as an even further tangent, while I'm on the subject of performance... Regarding the n800: The added memory and CPU power of the n800 is not an excuse for an application to be more liberal with memory and CPU. Maemo Mapper was written for the 770, and it will stay usable on the 770, no matter what. In fact, my personal opinion is that, in general, the added CPU and memory capabilities of the n800 should be used not to support hungrier applications but to better support existing applications (*ahem* Opera) and to better support running multiple applications at a time. 90 MB of available memory (when no other apps are running) is not justification to use all of that memory - other applications need memory, too.

Sure, if the demand is there, then maybe (in the distant future) a "higher end" version of Maemo Mapper could be released with the n800 in mind, but I will make sure that it also runs on the 770 (albeit more slowly), and I will strive to make it just as efficient on the n800 as it is now on the 770. Who knows, maybe in the future, there will be two versions (or runtime-configurable modes of operation) of Maemo Mapper: one for lean, mean, efficiency; and one with a slightly larger memory footprint. The latter will be aimed both for 770/n800 users that don't mind allocating more memory and sacrificing some responsiveness.

But until then, I'm ruling out "enhancements" that will inordinately increase memory or CPU requirements.

Re: Maemo Mapper: GPS for the Nokia 770
 

jpj:

Excuse my ignorance (so far I don't own a 770/N800 but hope to soon, and my experience with flash memory cards extends only to picture taking) but a question: with a 4 GB SD card, can the user format it such it consists of two equal size partitions (ie 2GB each) and therefore benefit from the more desireable 512 byte cluster granularity ?

gnuite:

Please keep up the outstanding development work on Maemo Mapper --- I'm looking forward to using it often when I purchase my Nokia IT. Thanks. !

Re: Maemo Mapper: GPS for the Nokia 770
 

Thank you, gnuite, for your thoughtful and well reasoned response. I'm personally unfamiliar with GPSDrive, but I trust your analysis. We're kindred spirits in terms of programming philosophy. Much of my best work has been on resource constrained platforms, and I've also enjoyed keeping those old legacy systems in play, even while pushing new code out on the latest and greatest. People might disagree on whether it's the right thing to do, but you won't get hear any arguments from me. Bottom line: You've clearly delineated the principles that define the product, and that must be the foundation of any future roadmap. Stay true to your own vision, and we'll all benefit. [/SOAPBOX]

Re: Maemo Mapper: GPS for the Nokia 770
 

No need to apologize - it's a good question, which I've been wondering about myself. If memory serves me, some 770 users have partitioned their MMC cards using Linux tools, yielding (for example) a dedicated swap partition and multiple ext2/ext3 partitions. There is a compatibility downside, since Windows won't mount those filesystems (as USB mass storage) without third party help. But I believe solutions are available.

I don't know whether the same can be accomplished with FAT32, but it would be worth finding out. One option I considered would be partitioning a 4GB card with street maps on one volume and topo maps on the other. You could then toggle freely between them in Maemo Mapper, much as you can in Google Maps (minus the hybrid overlay).

If nobody else chimes in with a definitive answer, I'll try some experiments.

Re: Maemo Mapper: GPS for the Nokia 770
 

Yes, it is certainly possible to format a single memory card with two separate file systems. They don't even have to both be the same type. In fact, that's the premise of the "extended root file system" hack that was popular on the 770.

The problem, as jpj stated, is that the Nokia 770 (out of the box) won't automatically mount both of the file systems. It will only mount the first one, and only if it is a FAT file system. It is possible (with some as-root hacking) to set up the 770 so that it automatically mounts the second file system; it just won't show up in any of the UI's, which is fine for Maemo Mapper's use (you can still use that second partition to store a Map Cache).

One strategy that you can use is to dedicate that second partition just for maps, sized exactly to the amount of map storage that you want. Then, you can write a maemo mapper startup script that will first mount the maps partition, then start maemo-mapper, and afterward unmount the partition.

Has anyone considered using jffs2 (the format that the 770/n800 uses for the root file system) for a map partition? I'm not entirely sure, so I can't confirm this, but I think jffs2 would not suffer at all from the large-block problem, since its blocks (or "nodes") are variable size.

It's not as convenience as FAT32 (not accessible or even formattable without MTD), but maybe it's worth investigating, if someone has the time and mkfs.jffs2 handy. If you do investigate, I would advise against using compression, since the PNG and JPEG images are already highly compressed.

Re: Maemo Mapper: GPS for the Nokia 770
 

Gnuite,

Would it be possible (in the next version of maemo mapper) to have an option to manually configure the GPX server?
I mean, a place in the config, where we set the GPX server url.
(similar to the URI)

thanks, ;)
lmf

Re: Maemo Mapper: GPS for the Nokia 770
 

Yeah, lmf, I think I can manage to fit that somewhere. Planning on writing your own GPX server? :)

(If yes, then, in the meantime, you can always write an entry in /etc/hosts (on your Nokia device) that maps www.gnuite.com to your server's IP address. Then just put your CGI script in the path "/cgi-bin/gpx.cgi" and you're good to go.)

Re: Maemo Mapper: GPS for the Nokia 770
 

thanks.
acttually.. I'm thinking of a way to do some simple gpx calculations while offline.. but that's another story... :)

but for now, what I really want is to be able to send the gpx requests to a socks proxy, (set up localy), so that I can bypass a firewall...
:rolleyes:

ps: thanks for the tip. I didn't think of that! :)

Re: Maemo Mapper: GPS for the Nokia 770
 

Hi, I just got a 770 from a friend in Nokia for free with a bluetooth gps rx'er :) ,as its old hat now that the new 800 is around.

This is a great program, so thanks to all those that have developed it, and I have it working fine in the uk with Virtual earth Hybrid/sts/imagery; also google sts, but can't get google imagery working - one issue.

Another thing I would like to do is load topo maps for walking eg 1:50k and 1:25k. Is it possible to load your own maps with say an ESRI world file:
Line 1: A, pixel size in the x direction in map units (ususally deg long per pixel)
Line 2: D: rotation about y axis (ususally 0)
Line 3: B: rotation about x axis (ususally 0)
Line 4: E: pixel size in the y direction in map units (ususally deg long per pixel)
Line 5: C: x coordinate of the center of the upper left pixel (51.45256)
Line 6: F: y coordinate of the center of the upper left pixel (-1.27247)

or possibly a geoTIFF, which has the geo coding within the tif header?
Hence one could scan, or download a piece of map, coordinate it using either method the load into a separate directory fo use? I can supply examples of both world file with tile and geoTIFF>

The only other way would be to cut up the map into the exact pieces that Maemomapper file directory expect, could be v labour intensive, especially the file creation/naming.

Cheers.

Re: Maemo Mapper: GPS for the Nokia 770
 

No, this is not possible with Maemo Mapper. And I hate to say it, but it probably will never be supported directly within Maemo Mapper. This is (I think) how GpsDrive works, and that's how Maemo Mapper started out, but it's just too cumbersome to work with on an scale larger than just a few dozens of maps.

It is possible to write a script or program to convert a GpsDrive-style image/metadata into Maemo Mapper's expected file hierarchy, but like you said, it would be a bit of work.

Topographic maps are available in the form of WMS maps. See this page for example URI formats.

http://hoohol.ath.cx/public/index.ph...eMM-Extensions

Note that you must install "proj" in order to use these maps. You don't however, need the patch mentioned on that website, as it has since been integrated directly in Maemo Mapper since version 1.3.

Re: Maemo Mapper: GPS for the Nokia 770
 

Thanks Gnunite, any idea where the repositories for GpsDrive and "proj" are; I shall experiment more....

Oh and do you know the url for google sat imagery in the uk, I have been looking at the html code but am new to this I think the answer is in this bit

{GLoadApi(["http://mt0.google.com/mt?n=404&v=w2.39&","http://mt1.google.com/mt?

n=404&v=w2.39&","http://mt2.google.com/mt?n=404&v=w2.39&","http://mt3.google.com/mt?n=404&v=w2.39&"],

["http://kh0.google.co.uk/kh?n=404&v=14&","http://kh1.google.co.uk/kh?

n=404&v=14&","http://kh2.google.co.uk/kh?n=404&v=14&","http://kh3.google.co.uk/kh?n=404&v=14&"],

["http://mt0.google.com/mt?n=404&v=w2t.40&","http://mt1.google.com/mt?

n=404&v=w2t.40&","http://mt2.google.com/mt?n=404&v=w2t.40&","http://mt3.google.com/mt?

n=404&v=w2t.40&"]);if (window.GJsLoaderInit) {GJsLoaderInit

("http://maps.google.com/mapfiles/maps2.73.js"

Thanks
kempja

Re: Maemo Mapper: GPS for the Nokia 770
 

GpsDrive is a separate application, not a repository. It's used primarily on laptops, but there used to be a Maemo port of it. I'm not sure if that still works. :rolleyes:

proj is available in any of the Maemo Extras repositories now (mistral, scirocco, or bora). You can install it from the Application Manager. Or you can download and install it from here (that package should work on both the 770 and the N800, despite it being in the bora repo).

http://kh.google.com/kh?n=404&v=99&t=%s

Re: Maemo Mapper: GPS for the Nokia 770
 

Looking for some help. I'm living currently in South Korea
trying to get maps to display in maemo mapper.
I downloaded maps views using win-mapper
but don't understand how to open the maps
with maemo-mapper without getting the gpx parsing error.
can anyone help me?

Re: Maemo Mapper: GPS for the Nokia 770
 

What version of maemo mapper are you using, on which tablet OS ?
Have you also tried getting the maps from mmapper itself on the table ?

Maybe I missed something, but I was under the impression that winmapper had not been updated in sync with mmapper, and the two were now incompatible ?

Re: Maemo Mapper: GPS for the Nokia 770
 

hey. I'm using maemo mapper with nokia 700 os2007, but when I open settings the first two fields (bluetooth and file path) are gray, can't select them. help? :)