Conflict when several apps use the accelerometers?
yorickmoko at gmail.com
Wed Jan 28 14:53:39 CET 2009
maybe this can be of help:
it interfaces with the car
On Tue, Jan 27, 2009 at 10:53 PM, Hendrik Siedelmann
<hendrik.siedelmann at googlemail.com> wrote:
> 2009/1/27, Helge Hafting <helge.hafting at hist.no>:
>> Gunnar Aastrand Grimnes wrote:
>>> This page does: http://wiki.openmoko.org/wiki/Accelerometer_Fundamentals
>>> Noise is around 3cm/s^2, i.e:
>>> It can fill in _short_ - 3-5s gaps in GPS coverage, if the orientation
>>> of the phone is known.
>> Not enough for a 4km tunnel then, which is 3 min when going 80km/h.
>> 5s is enough for a 111m tunnel, but 5s signal loss is usually not a
>> problem anyway.
>> Of course, the car speedometer readout can take care of speed and
>> braking/acceleration, the accelerometer would only be needed to notice
>> turning. Could be interesting to see where it thinks I am after 3 min,
>> if 5s is all I can expect. I guess those 3-5s is the interval where
>> precision matces the gps. But it will be useful for longer than that, as
>> long as estimate is more accurate than "stopped at the tunnel entrance."
>> The error increase with time, but so do the real distance from the entrance.
>> Helge Hafting
> Yes, I too think it would be useful for a longer period. In a time of
> 3-5 seconds one could propably get away with simply projecting the
> route at signal loss with constant speed. And I think navit snaps to
> streets anyway, so it wouldn't matter if its off by a bit.
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