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From: Martin Fuzzey <mfuzzey@parkeon.com>
To: linux-iio@vger.kernel.org
Subject: Acceleration units and mma8452 driver
Date: Fri, 11 Jul 2014 12:16:03 +0200	[thread overview]
Message-ID: <53BFB963.7070407@parkeon.com> (raw)

Hi all,

I'm new to iio and have a question on acceleration units.

Documentation/ABI/testing/sysfs-bus-iio states "after application of 
scale and offset are m/s^2"

However the mma8452 driver, when in 2G full scale mode provides a scale 
factor of 0.000977

/sys/bus/iio/devices/iio:device0# cat in_accel_scale
0.000977

Full scale positive raw value (12 bits) is 2047 so that gives 2G 
(0.000977 * 2047)

So this driver seems to be using G as units rather than m/s^2.

Am I misunderstanding or is this a driver or doc bug?

Regards,

Martin



             reply	other threads:[~2014-07-11 10:16 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-07-11 10:16 Martin Fuzzey [this message]
2014-07-11 11:31 ` Acceleration units and mma8452 driver Jonathan Cameron

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