RE: Comments on DeviceOrientation Event Specification, Editor's Draft 24 August 2010

See my comments inline below.

Claes

> -----Original Message-----
> From: Steve Block [mailto:steveblock@google.com]
> Sent: den 3 september 2010 12:44
> To: Dean Jackson
> Cc: Nilsson, Claes1; public-geolocation@w3.org
> Subject: Re: Comments on DeviceOrientation Event Specification,
> Editor's Draft 24 August 2010
> 
> > On both interfaces?
> Yes, I think so

I think that it is enough to have the "calibrated" attribute on the DeviceOrientation event only. It is needed for calibration of the compass algorithm to achieve a proper "circle" for compass heading. I can't see any "calibration" needs for raw accelerometer and gyro data
> 
> > I wonder if a simple "calibrated" property is better? Using "needs"
> in the name implies that the user
> > might have to do something (which they probably do, but the property
> is exposing the status of
> > calibration).
> Good point, I agree. Would isMagnetometerCalibrated or
> isCompassCalibrated be more clear, or do we want to leave it open to
> the possibility of other sensors also needing calibration?

I suggest "isCompassCalibrated" for the DeviceOrientation event.
> 
> > Regarding the example "A device in free-fall, with the screen
> horizontal and upmost, has an
> > accelerationIncludingGravity of zero and the following value for
> acceleration:"
> >
> > I believe an accelerometer will not be able to tell the direction of
> gravity in this situation.
> Right, but a device with a gyroscope too, which is required to
> eliminate the effects of gravity from the accelerometer measurements,
> will be able to, I think - at least in the short-term while
> integration errors are small.
> 
> --
> Google UK Limited
> Registered Office: Belgrave House, 76 Buckingham Palace Road, London
> SW1W 9TQ
> Registered in England Number: 3977902

Received on Friday, 3 September 2010 14:07:22 UTC