[ltp] Re: hdapsd during Intercity Express ride

[Jan Girlich]

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Am Donnerstag, den 15.10.2009, 15:00 +0200 schrieb Elias Oltmanns:
> Jan Girlich <vollkorn@cryptobitch.de> wrote:
> > Am Montag, den 12.10.2009, 20:48 +0200 schrieb Martin Steigerwald:
> >> I am currently traveling with a Intercity Express - mail will be sent=20
> >> later, cause no internet access in the moment - and found a cumbersome=
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> >> problem: There have been extreme lags during most common operations.
> >
> > I had the same problem during a bus ride. The system is rendered useles=
s
> > because of vibrations like from car engines.
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> From a mathematical point of view, I have serious doubts that the logic
> implemented in hdapsd is the right thing(TM). The problem is, as far as
> I'm aware, that we don't know exactly what the data returned by the
> accelerometer is supposed to represent, i.e. whether any kind of
> mathematical preprocessing is performed. I seem to remember that Shem
> performed some experiments when (s)he made changes to hdapsd. Whether
> real rides by bus or train had been among those tests, I don't recall.
>=20
> >> On Windows there is an option to ignore continued vibrations from such=
 a=20
> >> situation - we checked with a laptop from a co-worker. Is there such a=
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> >> knob for hdapsd? I thought about
> >
> > I don't know about any options, but I haven't looked into it, yet.
> >
> > But I also think the thresholds are set way too sensitive and hdaps kin=
d
> > of 'overreacts'.
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> What thresholds exactly? Have you tried the -s option yet? If you work
> on bus / train frequently, it might be worthwhile fiddling with this
> option and reporting your results to this list.

I did not have a look into hdapsd options at the time of writing the
former email. I just did so and will try using the -a option on the same
bus ride which rendered my system useless tomorrow and report here.

When I said 'thresholds' I meant the sensitivity level.

Cheers
Jan
--=20
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