[ltp] Re: hdapsd during Intercity Express ride

[Jan Girlich]

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Am Freitag, den 16.10.2009, 23:35 +0200 schrieb Micha Feigin:
> On Fri, 16 Oct 2009 01:14:34 +0200
> Jan Girlich <vollkorn@cryptobitch.de> wrote:
>=20
> > 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 s=
ent=20
> > > >> later, cause no internet access in the moment - and found a cumber=
some=20
> > > >> problem: There have been extreme lags during most common operation=
s.
> > > >
> > > > I had the same problem during a bus ride. The system is rendered us=
eless
> > > > because of vibrations like from car engines.
> > >=20
> > > From a mathematical point of view, I have serious doubts that the log=
ic
> > > 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 su=
ch a=20
> > > >> 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=
 kind
> > > > of 'overreacts'.
> > >=20
> > > What thresholds exactly? Have you tried the -s option yet? If you wor=
k
> > > on bus / train frequently, it might be worthwhile fiddling with this
> > > option and reporting your results to this list.
> >=20
> > 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 sam=
e
> > bus ride which rendered my system useless tomorrow and report here.
> >=20
> > When I said 'thresholds' I meant the sensitivity level.
> >
>=20
> Personally I had to play with the thresholds to get to the point where it=
 reacted to turning over (simulated fall) and large bumps but with the defa=
ults the train ride rendered the machine useless otherwise, even with the -=
a option

I activated the -a option today and pressed shift whenever I had the
feeling the laptop hard drive was stalling. Which was very often. But it
worked fine then and was still reacting to very strong movement like big
bumps or drops.

Now I'd like to know which threshold was set and used at this moment
because I would like to use it as a default. Any way I can get that
information from hdapsd when it changed the threshold because of -a?

Thanks
Jan
--=20
http://vollkorn.cryptobitch.de/
+49(0)40 85 40 69 76
+49(0)176 49 00 72 80
Jabber ID: vollkorn@jabber.ccc.de

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