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(REQ) COMPASS for Blackstone

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tsalta

Senior Member
Dec 25, 2008
2,461
721
London
Hello guy`s i was searching in internet for such a application like this but i don`t find anything cool also i think that everyone need to have COMPASS in the device and will be usefull.
So if anybody have idea or someone from the dev.. can make COMPASS to run in full screen on our Blackstones its posible to use GPS data or to use the G-senzor will be AWSOME!
Thanks in advance
 

Pandemoniumone

Senior Member
Apr 5, 2008
3,414
157
Sacramento
I was looking for an app like this as well recently but came up with nothing. I've seen the one for the iphone, it's pretty nice and simple.

I would be very interested in having something like this on my HD.
 

moshbeard

Senior Member
Nov 16, 2008
100
2
I don't understand how you could really put a compass in without the device actually containing a compass? I suppose using GPS it would be possible, but you'd have to physically move a few metres in a particular direction for it to know which way you're facing in order to tell you where north is in relation to yourself.
 

Pandemoniumone

Senior Member
Apr 5, 2008
3,414
157
Sacramento
I don't understand how you could really put a compass in without the device actually containing a compass? I suppose using GPS it would be possible, but you'd have to physically move a few metres in a particular direction for it to know which way you're facing in order to tell you where north is in relation to yourself.

Is that to say the iphone has a built in compass in addition to it's gps software?
 

mrmckeb

Senior Member
Apr 28, 2009
108
0
Sydney
One must have a compass in the device to have it in the software. All Windows Mobile 7 phones will have compasses in them... current WM phones do not...
 

Scrtcwlvl

Senior Member
Aug 4, 2008
260
21
The iPhone has no built in compass sensor as far as I know and I am still at a loss of how exactly this compass app actually works.

As far as I know, GPS programs generate your bearing (direction) based on your previous location compared to your current location. That is all fine and dandy provided I continue in that same direction. However, if I were to rotate my body (and the phone) 90 degrees to the left or right, my bearing wouldn't change until I began to walk in either direction.

What I am saying is, GPS based compasses would work and do work in navigation applications such as Tom Tom or Garmin... however for something like a hand held compass it would simply not work very well as an actual compass.



Did a bit of research on Compass Go - the iPhone compass application seen in the "Itchy" Commercial
Apptism -Compass Go Application said:
Find your way back in the easiest way!

Use Compass Go whenever you find it easier to follow an arrow than to read a map.
1. Tap 'Set Target', 'Use current location' and you are done!
2. To find your way back, watch the target arrow and distance change.
3. As you get closer, the background changes from blue to orange to green.

Perfect for finding your parked car, a place on a beach, a place in the forest or any situation where a map doesn't work well.

Application features:
* Simple GPS compass
* Accurate sun compass
* Target finding device
* Geocache search tool (set your target coordinates manually)
* Multi purpose navigation helper utility
* Magnetic declination indicator
* View positions in the map application with driving directions.

When using the live compass, make sure you walk in a straight line to get as accurate compass readings as possible.
You may also use this application together with an ordinary compass to achieve a very exact target finding device. Most useful in forests and other situations where the map doesn't work well. The application also has a built in magnetic declination indicator (red/white arrow) which compensates for the local declination.

If you don't have a GPS iPhone, your direction may be very wrong at times. Use the sun compass to confirm your direction. Generally it works quite well when there is good cell-phone coverage. You have to move more than the (±) accuracy limit to get a new reading.

So from what I understand this application works on GPS bearing... along with a few other features. However, just like the application listed below, in low signal areas it recommends you use the sun compass.

An application that just utilizes the sun and current time in order to create a compass heading is shown below.
Something like this could be easily made for the HD.
141compass21217720059.png
 
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purec0de

Senior Member
Nov 12, 2007
138
5
London
compass

As far as I know, GPS programs generate your bearing (direction) based on your previous location compared to your current location. That is all fine and dandy provided I continue in that same direction. However, if I were to rotate my body (and the phone) 90 degrees to the left or right, my bearing wouldn't change until I began to walk in either direction.

this is quite true..but what if you combine data from the G-Sensor?

i.e you would have to move a short distance to obtain a GPS bearing hence initialise the compass then (assuming the HD was facing forwards at the time) use rotational data from the G-Sensor to maintain the compass until the next GPS update. Of course this would still only work if the HD was always held by the user in the same orientation????


i am not sure how accurate the G-sensor is or what sort of data it returns?
but the combination of the to could theoretically produce a pseudo-compass

if i get time i may have a play with this theory..i am sure somewhere i have a G-sensor SDK...just need to figure out how to access the GPS,

Can anyone confirm whether the g sensor supports rotational data i.e. when held flat and you turn around?
struggling to find spec on the sensor (only done a quick search)
 
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Scrtcwlvl

Senior Member
Aug 4, 2008
260
21
There should be a way to use GPS to determine direction. I think that's how the compass in tomtom works.

Yes, this has been spoken of in nearly all of the previous posts. Your current GPS location is compared to your previous GPS location, a line is drawn between the two and that is your bearing. (direction)

this is quite true..but what if you combine data from the G-Sensor?
i.e you would have to move a short distance to obtain a GPS bearing hence initialise the compass then (assuming the HD was facing forwards at the time) use rotational data from the G-Sensor to maintain the compass until the next GPS update. Of course this would still only work if the HD was always held by the user in the same orientation????
i am not sure how accurate the G-sensor is or what sort of data it returns?
but the combination of the to could theoretically produce a pseudo-compass
if i get time i may have a play with this theory..i am sure somewhere i have a G-sensor SDK...just need to figure out how to access the GPS,
Can anyone confirm whether the g sensor supports rotational data i.e. when held flat and you turn around?
struggling to find spec on the sensor (only done a quick search)

The G-Sensor is just that, it senses the force of gravity or acceleration in 2 directions, an accelerometer. (AFAIK it is only a 2 axis unit, although it could be a 3 axis but that would seem unneeded) When the phone is laid flat, this is seen as tilt both forward and back along with side to side. When the phone is held upright one directional is maxed out where the other will detect tilt rotation of the phone left and right. (Or swinging of the phone left and right, this part is key to perhaps getting this to work)

The most predominate force, gravity is always down and because of this it is what one would usually use for screen rotation and games.

What you are thinking of is a gyroscopic sensor, a sensor capable of reporting rotational information, which would be very nice however is not included on our device.

However all hope is not lost, our sensor is capable of telling us acceleration in the left or right direction. So if you are holding the phone upright and rotate your body left and right, the acceleration would be recorded by the sensor. One thing you can try, is based on the acceleration and time (start and stop time of the acceleration) use this to try interpret how far the user has rotated themselves. Through some basic physics equations one could ROUGHLY give an idea of how far one has rotated from the predetermined north direction.
Several problems persist through this method, as simply how far the phone is held out from your body can greatly effect the arc length of the rotation resulting in an over / under estimation of the movement based on the acceleration data captured by the G-Sensor.
 
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purec0de

Senior Member
Nov 12, 2007
138
5
London
What you are thinking of is a gyroscopic sensor, a sensor capable of reporting rotational information, which would be very nice however is not included on our device.

thanks for confirming my suspicions, after playing a little with the G-sens SDK i realised this.

dam, if only it was gyroscopic!....

but then i suppose i could say dam if only it had a compass!! lol

anyways, nice to see some discussion at a technical level rather than just a simple "not possible"

cheers