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View Full Version : GPS Compass?


geneven
2007-02-27, 06:16
I wonder if one could create a GPS Compass? It would imitate the face of a compass and point to true north from your tablet computer. Maybe such a thing already exists?

aflegg
2007-02-27, 09:18
Maemo Mapper has a mini-compass when connected to a GPS and "GPS > Show info" is enabled.

gnuite
2007-02-27, 20:43
Maemo Mapper has a mini-compass when connected to a GPS and "GPS > Show info" is enabled.
That compass only shows what your heading is (or, rather, the
heading of your GPS receiver). Rotating your Nokia device will not, for example, change the appearance of the compass (relative to the device).

Do do what geneven asks, you would need a gyro, I think, and it would have to be either built into the Nokia device or firmly attached to it.

mwiktowy
2007-02-27, 23:20
A GPS only gives you a x,y (and maybe z) point. In order to get a direction to compare to North (the definition of a compass) you would need two GPS points. You can either do that by using two points given by a single GPS at different times while you are in motion (giving you a track direction ... something maemo mapper does rather well) or use two or more GPSs with a known relation to you. I don't know of any maemo app that will read two GPSs simultaneously and present the results usefully. I think some survey tools do this and I know that some satellites are using this for rough attitude determination.

A gyroscope will give you your relative orientation. You still need to define a baseline orientation periodically using some external measure. Even the best gyros will drift.

There are electronic compasses that use a magnetic sensor to detect the local geomagnetic field direction rather than the old floating magnetic needle. I don't know of any bluetooth-enabled ones.

TA-t3
2007-02-28, 13:04
And GPS compasses also only work when you're moving..

bac522
2007-02-28, 15:01
http://images.ems.com/media/images/products/001/00168/0016867/001686799/001686799_green_200.jpg
+
http://www.hardwarestore.com/media/product/149682_front200.jpg
+
http://www.nokia.fi/puhelimet/puhelinmallit/770/img/index_770_primary.jpg

Bonus Thermometer thrown in :D

RussNelson
2007-09-22, 01:29
I have a WinTec WBT-100. It has a compass, whose direction it reports on a proprietary NMEA sentence.

bac522
2007-09-22, 03:11
http://images.ems.com/media/images/products/001/00168/0016867/001686799/001686799_green_200.jpg
+
http://www.hardwarestore.com/media/product/149682_front200.jpg
+
http://www.nokia.fi/puhelimet/puhelinmallit/770/img/index_770_primary.jpg

Bonus Thermometer thrown in :D

Elmer's glue probably won't hold it well though.

dan67sf
2007-09-22, 03:38
Elmer's glue probably won't hold it well though.

I prefer Velcro over Elmer's for stuff like that, although Elmer's may have more nutritional value.

dan67sf
2007-09-22, 18:54
Just an idealeo,

I know there are digital compass's that show the direction you are going and the Nokia N800 and the 770 both have magnets on them. Just have a to figure out how to make these usable, some way to sense and send the data, to the devices.

barry99705
2007-09-22, 21:37
Just an idealeo,

I know there are digital compass's that show the direction you are going and the Nokia N800 and the 770 both have magnets on them. Just have a to figure out how to make these usable, some way to sense and send the data, to the devices.

They're just linear Hall Effect sensors. I don't see how they are supposed to tell direction. Would be easier to just use a gps that has a real electronic compass.

bunanson
2007-10-01, 03:45
I think Gnuite + Andrew already answered the question, or maybe I am missing something, all OP needs to do, is to hold the GPS with the tablet together in one piece, turn on GPS>GPS info, and walked a few feet, that will give you the direction. That is what I have been doing when I want to find out. Anyway, its nice to see so many brains to attack a task of such a calibre, and BAC522 solution is the cutest of all;)


bun