Can the iPhone determine if you're facing north, south, east or west?

Question

Can the iPhone determine if you\'re facing north, south, east or west?

Answer 1

This maybe a bit of a hack but what I was doing was keeping tracking of the lat/long and then determining by that the direction.

Within my code that returns the GPS information I created a delegate that would return back the latitude and longitude

[[self delegate] currentDirectionLat:newLocation.coordinate.latitude Long:newLocation.coordinate.longitude];

The code that was consuming the delegate would then have a method like so to get the coordinates and then set a label on the screen to the direction.

-(void)currentDirectionLat:(float)latitude Long:(float)longitude
{
    prevLongitude = currentLongitude;
    prevLatitude  = currentLatitude;

    currentLongitude = longitude;
    currentLatitude = latitude;

    NSString *latDirection = @"";
    if (currentLatitude > prevLatitude)
        latDirection = @"N";
    else if (currentLatitude < prevLatitude)
        latDirection = @"S";

    NSString *longDirection = @"";
    if (currentLongitude > prevLongitude)
        longDirection = @"E";
    else if (currentLongitude < prevLongitude)
        longDirection = @"W";

    if ([longDirection length] > 0)
        [lblDirection setText:[NSString stringWithFormat:@"%@%@",latDirection,longDirection]];  
}

I've not 100% tested this out but seems to have worked on my one application I was writing. If you want more information please let me know and I can forward you my code that I've done on it.

You will also not get a good reading until the iPhone is moving to get the lat and long change. However, this does not take much to get it to change!