[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <46278CDD.2000007@gmail.com>
Date: Thu, 19 Apr 2007 17:38:05 +0200
From: Jiri Slaby <jirislaby@...il.com>
To: Dmitry Torokhov <dtor@...ightbb.com>
Cc: johann deneux <johann.deneux@...il.com>,
linux-kernel@...r.kernel.org, stenyak@...il.com,
linux-input@...ey.karlin.mff.cuni.cz
Subject: Re: [RFC 1/2] Input: ff, add FF_RAW effect
Dmitry Torokhov napsal(a):
> I have been thinking about this and I don't think that exporting motor
> data is a good idea, at least not in case of Phantom driver. The fact
> that there are 3 motors is a hardware implementation detail and it
> is not interesting for general application.
Ok, so what about torques (despite it's still something like FF_RAW or motor
descriptor)? It seems not to be so bad called effect name -- not only
phantom uses torques on motors as an unit of force, for example I get this
by quick googling:
http://www.caip.rutgers.edu/~bouzit/lrp/glove.html
They use there some motors with 14 torque values too, so the phantom isn't
the only device which uses this approach.
> My understanding that the end result of controlling these 3 motors
Actually there is also a version with 6 motors :).
> is a force vector (I don't know if there is such english term, this
> is a literal translation from russian) applied to user's hand.
Better say torques vector. You must compute a torque for each place from the
3d (or bigger) vector of forces in different way for each device that exists
-- this means forces are not independent unit, torques are in the meaning of
layer which doesn't care about what is connected above and below it.
> If we are interested in using FF API we need to come up with a way
> to express this effect without exposing implementation details of
> one particular device.
Still, torques are better named raw/motor values, which goes to the device
and I'm sceptic about inventing something class-better than this.
regards,
--
http://www.fi.muni.cz/~xslaby/ Jiri Slaby
faculty of informatics, masaryk university, brno, cz
e-mail: jirislaby gmail com, gpg pubkey fingerprint:
B674 9967 0407 CE62 ACC8 22A0 32CC 55C3 39D4 7A7E
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists