Thread: Maemo Mapper: GPS for the Nokia 770
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2006-05-22 , 14:26
Posts: 1,245 | Thanked: 421 times | Joined on Dec 2005
#155
Originally Posted by bradb
Actually, I've been using maemo mapper with a cell phone and bluetooth gps and my experience has been about the same: It seems to lock up after running fine for 10-20 minutes... I've managed to give it a "kick-start" by pressing the on-off button (is this the same as closing the lid?)

A few other comments:

- Downloading via cell is a problem, at least when speeds are slower than EDGE. The user interface seems to freeze while the map is loading, and at 30 miles per hour (or more) I don't think maemo mapper will ever keep up (since more and more maps need to be loaded).
At 30 mph or more, you probably don't need to be at the most detailed zoom level; the further you zoom out, the fewer maps you will need to download, which should help alleviate bandwidth issues.

Originally Posted by bradb
This could be a problem because I'm in-between cell towers or maybe the 770 just doesn't have enough oompf to run multiple threads efficiently.

And a EDGE speeds, the display can get a little jerky when downloading (though I have no idea of the network conditions when the problem occurs) but it's still usable.

So in my limited testing, I don't think it's practical to download maps are you travel - yet. But when it works it's very cool.
I don't think it's a thread inefficiency problem. I've tested auto-downloading on my Nokia 770 over my high-speed WAN (panning around a lot to stress the system) without any maleffect on the UI, so it's more likely a bandwidth problem, although that shouldn't affect the UI itself.

Originally Posted by bradb
- Twice I've lost my gps fix for about 40 seconds (the west hills tunnels). As I was driving, my girlfriend was watching the 770. She told me that the track suddenly jumped "way off" but after we exited the tunnel, tracking resumed as expected. Certainly a minor glitch, but I wonder if sanity checking of the gps positions returned (vs. the current speed/position) isn't warranted?
There is a built-in sanity check in the NMEA protocol, so unless your GPS is ignoring that part of the protocol, it shouldn't plot a point unless it is considered "valid" by the GPS receiver. This is, of course, receiver-dependent.

[QUOTE=bradb]- flite works great, but the volume is so low I don't think this is really useful without earphones. And by great I mean it has a terrible voice but is a real cool hack :-)

Originally Posted by bradb
- I think the latest firmware 5.2006.13-7 has improved system stability when more than one bluetooth device is connected at the same time (or so it seems). And it seems that using wifi and bluetooth at the same time is also improved. But maemo mapper seems to kill any active connections when it starts, so I've gotten used to making sure I don't connect to T-Mobile until _after_ the application is started.
I've noticed this sometimes with my WAN connection, but only when that WAN connection is not currently in use. If I'm listening to internet radio while I start Maemo Mapper, for example, I have no problems. It's bizarre, but I'm not sure there's anything I can do about it without moving all of the bluetooth connection code outside of Maemo Mapper.

Originally Posted by bradb
I'll report more as I keep testing.

And good news about gpsd integration for the next version - I'm getting ready to put a soekris box in my trunk (ala stompbox) and I was hoping to use the 770 as the front-end.
GPSD support (which will hopefully also assuage some of the nastier connection-related problems with Maemo Mapper) is coming with Maemo Mapper v0.2, which will be released for the 2006 OS.

I'll be releasing a v0.1.1 later this week to address some of the reliability issues.