Notices

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.

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

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.

Pre-download that is...

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.

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

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.

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.

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!

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!