Unconventional compass
 

I've got a proposition for a compass that isn't mentionned in the wiki.

I've looked at the light sensor of the n900.
It is very complex!!!
It is even able to distinquish different colors. (The lux are integrated over a spectrum).

If there was an expert for hardware he could even write an application for color recognition with this sensor.

It would be possible to construct a compass with that.

You take a little ball compass (1cm diameter). You color the different parts of the compass: for example: North is red, less north is less red. West is blue, less west is less blue. Yellow is up, no yellow is down.
This colored ball compass you put on the light sensor. It makes a color analysis and gives the direction!

Wouldn't that be wunderful?

Re: Unconventional compass
 

that sounds very creative!
try it! im curious if it will work
maybe if someone takes care of the hardware part the sftware will come up also!
burt... very creative!!

Re: Unconventional compass
 

Unfortunately in a real world objects don't have color. If you light it with white lite object would have one color, at sunset light would be much more red and object's color would become warmer. At lite of night outdoor sodium lamps everything is yellow, all other colors turn to black.
But can you please describe how to read channels from light sensor?

Re: digital compass on n900
 

Yeah - the lack of a compass does make the GPS very unpredictable. A strange miss, and one that makes the N900 even more of a half-baked handset than it is.

Quite apart from star gazing apps, digital compasses also make augmented reality apps possible - Although GoSkyWatch is awesome, especially on the iPad.

Re: digital compass on n900
 

@KiberGUS

Did you also think about fluorescent/ luminescent paint ?

Re: digital compass on n900
 

http://www.stellarium.org/

I'm looking for star gazing apps for the N900 - i see the one you mentioned supports linux - does that mean it can run on the n900

if so... what do i have to do?

thanks! :)

Re: digital compass on n900
 

i'm not sure but a hardware is required (which the n900 is lacking)

Re: digital compass on n900
 

It's a real shame, would make it possible to write some cool augmented reality apps if it were present (i.e. something like camera view with overlaid locations of landmarks, wikipedia entries, etc.)

Re: digital compass on n900
 

I have an idea which I think will work for "emulating" compass functionality on the N900. Here is how it would work:

Using the date, time, and GPS coordinates, the app should be able to know where the sun or moon is located in the sky and their direction on a compass.

With GPS turned on and the date and time set correctly, the user can point to the sun during the day, or the north pole star (or moon) during the night.

The app should now be able to know which direction on the compass the user is holding the phone to. Consider this the user calibrating or setting/resetting the "compass" app.

From that point on, the app uses information from the phone's hardware (GPS and accelerometer) to update the "compass" information as the user moves the phone around.

If the accelerometer works the way I understand it works from this page (http://wiki.forum.nokia.com/index.ph..._N900_using_Qt), then this should work pretty well, shouldn't it?

EDIT: After playing with the AccDisplay app, I don't think the accelerometer will help keep track of the orientation. The accelerometer can detect all movements and orientation except for rotations around the z-axis because that's the same access gravity pulls at! Unfortunately, that's exactly the kind of rotation you'd need in a compass application :( I guess the only remaining solution is the information from the GPS hardware, which relies on phone movement, but that only tells you the direction the phone is moving in, not necessarily where it's oriented. Big bummer :(

Hamzeh

Re: digital compass on n900
 

And how would it work if you can't see the sun (cloudy day, or even night time)?
I have a better idea for you, and it doesn't require any device what-so-ever - if you're outside, you may sometimes notice that the sun rises from the east and sets in the west, so if its not exactly the middle of the day (12:00), you should be able to know roughly which direction is the east or west respectively, thus finding the north :)
There is another way of finding out, which is a bit more accurate which I was taught during my military service, but I'm afraid its not that easy to explain in words ;)