To read nmea sentences you don't need to have your gps unit to get fix first.
So just run any gps utility, VisualGPS or another
and record nmea sentences to see if your gps unit can send anything.

GPS diagnostics is what can help you to see what's wrong with your gps navigation.

Darius

How can you usu maemo Mapping with N810, it seemingly requires external gps, cannot connect to the internal gps!?

Fire off map first and kickstart the gps app.
Search

Is there a diagnostics or debug utility for the N8x0? If things don't work I'd like to see why.

The built-in applications show four green bars when everything is fine and if not all bars are grey. I cannot really interpret this. The green bars probably stand for visible/used satellites, the height of the bars is probably signal strength. So what do the grey bars mean? (invisible and zero signal?)

I don't fully understand how GPS works, but everyone knows it requires a signal from minimum three satellites and some data (time, know position of satellites). This data can be received from the satellites themselves. Thus, a cold start is possible but will take time. However knowing what time it is and where you are (approx) should allow for a faster warm start. Most complains here are about this warm start failing.

Now it would be nice to see why the warm start fails. No signal at all? Not enough data? Stupid software? (Does it forget data?)

Any ideas?

For any GPS, the first fix after being moved hundreds of miles can take a long time, 5-15 minutes depending on conditions.

The N810 after first fix can take 2-3 minutes. Not moving and open sky is better. The GPS is fairly sensitive, but isn't the best because it has to be small and use little power, but I've gotten fixes near windows indoors. I'm surprised at how good it does that, and bluetooth, and wifi given the package size.

My BT GPS is much better.

http://www.buygpsnow.com/GlobalTop-G...-Off)_914.aspx

It gets fixes even indoors (including WAAS). Paired easily with the n810. Under a minute to a fix, usually WAAS well under 3 minutes. $50 with shipping. Well worth it. But if you've seen any external GPS, it usually has a just under one inch by one inch antenna. There's no way to put that into an n810, however there are GPS repeaters which might work too, but wouldn't be better than the above.

A thin version of the GPS is here:

http://www.buygpsnow.com/Product/Glo...unt)__925.aspx

Semsons.com has the first one, and there may be other choices, but I've gotten several.

And the N810 will work at 5Hz. I need to update a mapping program I did for the Zaurus that used US Census maps (Qt - sigh), but plotted everything and used small but fast compression. All roads, cities, lakes, parks, etc. would fit on the n810.

Hi,
you can read and save nmea sentences directly from gps chip to a file
from the very beginning (hot or cold start) so no-fix recording is possible.
Saved nmea sentences you can open in VisualGPS or another
off-line gps utility to see a number of satellites in view, signal strength
and more.
If I open terminal I can read nmea sentences on-the-fly and save to a file.

Darius