cancel
Showing results for 
Search instead for 
Did you mean: 

Another Satnav question - USB disc emulation

alanb
Grafter
Posts: 459
Registered: 24-05-2007

Another Satnav question - USB disc emulation

For the Garmin and Navman owners who posted on madjbright's earlier thread ...
Can anyone can tell me if their Garmin or Navman models emulate a USB disc drive when plugged into a computer? I'm looking for a replacement for my old Tomtom, which does do it and is one of the main reasons I purchased a Tomtom.
Disc emulation is important for me because I use Linux computers which means that the Windows/Apple drivers that are normally supplied with most satnavs are no use to me. With disc emulation I can at least back-up the contents of the Tomtom memory and install POI files. (I'm not interested in installing map updates, speed camera info, and so on.)
18 REPLIES
pierre_pierre
Grafter
Posts: 19,757
Registered: 30-07-2007

Re: Another Satnav question - USB disc emulation

I think I know what you mean, I have a Navman N20, If I connect that to my PC without the Navman program, the below is the structure, sometimes the POI delete function doesnt work correctly so I have to manually delete them
You problem will be that the interface program merges and reformats the base information before writing to the Navman, which has a win OS
Community Veteran
Posts: 7,149
Thanks: 51
Fixes: 2
Registered: 30-08-2007

Re: Another Satnav question - USB disc emulation

@alanb, I have a Navman S503D, that does show as a separate drive when used with the Navdesk software. However I have just been having an email exchange with Navman on this very subject, when I was trying to transfer POI's on to the apparently 250Mb+ space available or onto the SD card. The upshot was that I am not able to use the SD card for the purpose as the device doesn't read the card, its only used for map upgrades.
When asked what the spare space on the device was for then, I got a deathly silence.
Moral, get hold of one of the earlier models N series if you can (still available through Amazon) Which another correspondent of this forum tells me is rather better in this respect. The S series is fine if you use as is from the box, if you're interested in playing with it think again, although I did successfully install 3rd party safety camera details, but am in danger of exceeding its 12000 limit if I include mobile cameras. If you then try to uninstall the Navman safety cameras in the hope of creating more room, what you actually do is remove the icons and thats all.
Experience; is something you gain, just after you needed it most.

When faced with two choices, simply toss a coin. It works not because it settles the question for you. But because in that brief moment while the coin is in the air. You suddenly know what you are hoping for.
pierre_pierre
Grafter
Posts: 19,757
Registered: 30-07-2007

Re: Another Satnav question - USB disc emulation

alanb
Grafter
Posts: 459
Registered: 24-05-2007

Re: Another Satnav question - USB disc emulation

Thanks to both of you for your thoughts.  Smiley
It looks like it might be worth my while to search for more detailed technical information on the Navman models that you've mentioned. (There is a possibility that the Navman installer added a proprietary device driver to your Windows configuration when you installed your Navdesk software, in which case they'd be no good for me. But if they are compatible with the the standard USB mass storage device driver, which is the driver that detects and supports external USB disc drives, then I may be able to use them.)
This need not necessarily be a deal breaker for me pierre_pierre ...
Quote from: pierre_pierre
You problem will be that the interface program merges and reformats the base information before writing to the Navman, which has a win OS

If the structure of the Navman POI files has been documented somewhere on the Web, and if they're not horrendously complex, I'd write some software to massage POI data into the correct file format. I've done this already for my Tomtom. The early Navman devices used re-badged Tomtom software, so there is a slight possibility that Tomtom and Navman POI files have some shared common data structure, which would make this job easier.

Sadly, Tomtom seem to be heading down this route with some of their newest models Petlew, which may make them unsuitable for what I want to do ...
Quote from: Petlew
@alanb, I have a Navman S503D, that does show as a separate drive when used with the Navdesk software. However I have just been having an email exchange with Navman on this very subject, when I was trying to transfer POI's on to the apparently 250Mb+ space available or onto the SD card. The upshot was that I am not able to use the SD card for the purpose as the device doesn't read the card, its only used for map upgrades.

It would be disappointing because the software for Tomtom's entire range of self-contained satnavs is built on embedded Linux, but they appear to be uninterested in providing any supported options for interfacing to a Linux computer, let alone a Linux version of their 'Tomtom Home' software.
pierre_pierre
Grafter
Posts: 19,757
Registered: 30-07-2007

Re: Another Satnav question - USB disc emulation

Quote
The early Navman devices used re-badged Tomtom software, so there is a slight possibility that Tomtom and Navman POI files have some shared common data structure, which would make this job easier.

The Tom Tom files use an OV2 structure, the Navman a plain CSV  three items, Lat, Long, Description
Not sure what the TT OV2 is but it is not plain listable
alanb
Grafter
Posts: 459
Registered: 24-05-2007

Re: Another Satnav question - USB disc emulation

That's interesting. OV2 files contain the same three data elements, with some additional records that contain the co-ordinates of the smallest square on the map that can surround the POIs in the file. They are in a binary file format, which is why you can't list their contents easily, but the structure is fairly simple all the same.
CSV files could be a doddle to use, no special software required, just import and export with a spreadsheet program! Have you by any chance ever tried using Windows Explorer to drag Navman POI files onto your satnav, and did it recognise them correctly? (Don't try it if you haven't already done it, I wouldn't want you to risk messing up your navigator. No doubt I'll be able to find an answer on the web somewhere.)
Community Veteran
Posts: 1,886
Registered: 05-04-2007

Re: Another Satnav question - USB disc emulation

Just to add my 2p worth
My Garmin Nuvi 205T does indeed emulate a USB drive when it is plugged in and you can explore pretty much the whole device.
I used to have a Navman F20, but found the accuracy and the mapping shockingly bad, plus Navman didn't give me any free map upgrades like Garmin did - Garmin upgraded my UKIE maps with full European ones (mostly major roads, but definitely street level in France) not long after I registered my device.
It's certainly worth looking at. it does exactly what it says on the tin, and IMO is far better than the Navman..
pierre_pierre
Grafter
Posts: 19,757
Registered: 30-07-2007

Re: Another Satnav question - USB disc emulation

sorry no luck the files produced on the navman have the following suffixes  .bm  and .map, I tried altering the .bm to .bmp but none of my vieweres wanted to know, like wise .map is a binary file, the one I tried original CSV was 136 kb and reduced to 25kb
alanb
Grafter
Posts: 459
Registered: 24-05-2007

Re: Another Satnav question - USB disc emulation

Ahaa! I thought it sounded a bit too simple. I thought that you meant that the contents of the files on the navigator were in CSV layout.
The Navman MAP and BM files sound like they might have a similar purpose to Tomtom OV2 and BMP files. For the Tomtom, one contains a compressed binary list of POIs, and the other is a small image that is used to display a POI on the navigator screen. Many years ago Tomtom distributed a couple of little utility programs that convert a CSV file to an OV2 and vice-versa. But it sounds like Navman POI files undergo a similar process. My own version of these utilities for Linux does the same, and allows me to create and edit my own Tomtom OV2 files on a PC. I wouldn't expect it to be too difficult to do it for Navman files too, unless they do something a lot more complex than Tomtom when creating the MAP and BM files or the file layouts are secret.
Thanks for the feedback pierre_pierre. It gives me some confidence that it is worth taking a detailed look at navigators other than Tomtom. Now I just have to work out which ones are compatible with the USB mass storage driver, otherwise I've wasted everybody's time.
By the way, if you're in the the mood for tinkering for the sake of tinkering, you might find that the file you thought was a BMP is a GIF. I'm pretty sure that was the case for early Tomtom products (even though they label them as BMP). But ICO (for icon) is a possibility too.
alanb
Grafter
Posts: 459
Registered: 24-05-2007

Re: Another Satnav question - USB disc emulation

Thanks Chemical Brother. That's another model to add to my list for the Google treatment.
madjbright
Grafter
Posts: 184
Registered: 09-06-2007

Re: Another Satnav question - USB disc emulation

Quote from: alanb
Now I just have to work out which ones are compatible with the USB mass storage driver, otherwise I've wasted everybody's time.

If I plug my Navman S70 3D into the USB port with no Navman software running it id recognised as a Removable Disk and I can view the contents with Windows explorer just like any other disk drive or memory stick if that is what yu are asking.
Community Veteran
Posts: 7,149
Thanks: 51
Fixes: 2
Registered: 30-08-2007

Re: Another Satnav question - USB disc emulation

Quote from: madjbright
If I plug my Navman S70 3D into the USB port with no Navman software running it id recognised as a Removable Disk and I can view the contents with Windows explorer just like any other disk drive or memory stick if that is what yu are asking.

Indeed it does madjbright, never thought of looking without Navdesk, but rather a lot of new file extensions are needed to show anything worthwhile.
Experience; is something you gain, just after you needed it most.

When faced with two choices, simply toss a coin. It works not because it settles the question for you. But because in that brief moment while the coin is in the air. You suddenly know what you are hoping for.
alanb
Grafter
Posts: 459
Registered: 24-05-2007

Re: Another Satnav question - USB disc emulation

Quote from: madjbright
If I plug my Navman S70 3D into the USB port with no Navman software running it id recognised as a Removable Disk and I can view the contents with Windows explorer just like any other disk drive or memory stick if that is what yu are asking.

Thanks madjbright. Every little bit of information helps.
What I need to go and investigate though is whether a Navman (or a Garmin) relies on a custom Windows device driver to makes it appear as a removable disc. This may not be Navdesk, it could be a separate piece of software that is installed along with the Navdesk software.
I've been doing some searching on the web but have not found a reliable answer so far. Perhaps I should throw a 'satnav party' and invite friends and neighbours to come along and plug their navigators into one of my Linux boxes to see if they'll play together.  Grin
alanb
Grafter
Posts: 459
Registered: 24-05-2007

Re: Another Satnav question - USB disc emulation

I've also been Gurgling for information on the contents of the Navman POI files, as they exist in the navigator. That looks even less promising. There is almost nothing of any significance on the web. Which would suggest that they're not in the public domain and nobody's managed to work out what they contain, or they're too complex.