From: "AnilKumar, Chimata" <anilkumar@ti.com>
To: Chinmay V S <cvs268@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>,
"gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
"eric.piel@tremplin-utc.net" <eric.piel@tremplin-utc.net>,
"jic23@cam.ac.uk" <jic23@cam.ac.uk>,
"greg@kroah.com" <greg@kroah.com>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"broonie@opensource.wolfsonmicro.com"
<broonie@opensource.wolfsonmicro.com>,
"dmitry.torokhov@gmail.com" <dmitry.torokhov@gmail.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v2] lis3lv02d: Add STMicroelectronics lis331dlh digital accelerometer
Date: Wed, 22 Aug 2012 15:40:25 +0000 [thread overview]
Message-ID: <331ABD5ECB02734CA317220B2BBEABC13EA1BDA9@DBDE01.ent.ti.com> (raw)
In-Reply-To: <CAK-9PRBDpxtrxZWL_x9Uz--GMWDN5anyB_fuKtLrvZcLoRR+FQ@mail.gmail.com>
On Wed, Aug 22, 2012 at 16:09:22, Chinmay V S wrote:
> Hmmm. Interesting. As i understand LIS331DLH provides 16bit data
> irrespective of the full-scale/sensitivity configuration. Hence we
> could effectively map +/-2G to +/-32768(signed 16bit 2's complement).
> According to the current-patch right-shifting the register values by
> 4(i.e. reducing 16bit --> 12bit) will mean that we lose accuracy by
> ~1mG.
>
> Clearly this will NOT affect use-case like display-orientation in
> smart-phones, but surely medical and industrial applications WILL
> benefit from the additional accuracy by utilising the entire 16-bit
> resolution provided by LIS331DLH hardware.
>
> I went through the LIS331DLH datasheet/application-note from
> http://www.st.com/internet/analog/product/218132.jsp and i'm a bit
> confused from your statement about +/-2G being 12bit data. Nowhere is
> it mentioned that LIS331DLH provides +/-2G|+/-4G|+/-8G as 12|13|14 bit
> data respectively. Then again i might be wrong...
>
Look at this application note which talks about the outdata values
for 2G range (page 12/31) http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/APPLICATION_NOTE/CD00215823.pdf
Corresponding to the 4G and 8G I got the details form older
patches (SHIFT_ADJ_4G and SHIFT_ADJ_8G).
http://driverdev.linuxdriverproject.org/pipermail/devel/2010-November/009685.html
We can easily interpret number of bits for 4G and 8G from 2G
information.
Thanks
AnilKumar
next prev parent reply other threads:[~2012-08-22 15:40 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-22 6:30 [PATCH v2] lis3lv02d: Add STMicroelectronics lis331dlh digital accelerometer AnilKumar Ch
2012-08-22 7:48 ` Arnd Bergmann
2012-08-22 8:44 ` Chinmay V S
2012-08-22 9:00 ` AnilKumar, Chimata
2012-08-22 10:39 ` Chinmay V S
2012-08-22 15:40 ` AnilKumar, Chimata [this message]
2012-08-22 16:54 ` Chinmay V S
2012-08-23 10:00 ` AnilKumar, Chimata
2012-08-23 10:23 ` Chinmay V S
2012-08-23 11:15 ` AnilKumar, Chimata
2012-08-23 11:33 ` Chinmay V S
2012-08-28 5:45 ` AnilKumar, Chimata
2012-09-23 21:38 ` Éric Piel
2012-09-24 5:46 ` AnilKumar, Chimata
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