On Mon, Jan 26, 2015 at 1:07 AM, Jonathan Cameron <jic23@xxxxxxxxxx> wrote: > On 11/01/15 19:10, Irina Tirdea wrote: >> The pedometer needs to filter out false steps that might be generated by >> tapping the foot, sitting, etc. To do that it computes the number of >> steps that occur in a given time and decides the user is moving only >> if this value is over a threshold. E.g.: the user starts moving only >> if he takes 4 steps in 3 seconds. This filter is applied only when >> the user starts moving. >> >> A device that has such pedometer functionality is Freescale's MMA9553L: >> http://www.freescale.com/files/sensors/doc/ref_manual/MMA9553LSWRM.pdf. >> >> To export this feature, this patch introduces >> IIO_CHAN_INFO_FILTER_OUTLIERS_THRESH and IIO_CHAN_INFO_FILTER_OUTLIERS_PERIOD. >> For the pedometer, in_steps_filter_outlier_thresh will specify the number of >> steps that need to occur in in_steps_filter_outlier_period seconds so that >> the pedometer decides the user is moving. >> >> Signed-off-by: Irina Tirdea <irina.tirdea@xxxxxxxxx> > I wonder if the naming here is infact too generic. They aren't what > people would normally think of as outliers. That would be removing > missidentified steps mid way through grabbing data (to my mind). > > These are almost a 'debounce' of the transition from stationary to > walking... Maybe there is another better term. All suggestions welcome! What about: in_steps_debounce_count instead of in_steps_filter_outlier_thresh and in_steps_debounce_delay instead of in_steps_filter_outlier_period. Also in_steps_debounce_time could work for in_steps_filter_outlier_period. > >> --- >> Documentation/ABI/testing/sysfs-bus-iio | 21 +++++++++++++++++++++ >> drivers/iio/industrialio-core.c | 2 ++ >> include/linux/iio/iio.h | 2 ++ >> 3 files changed, 25 insertions(+) >> >> diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio >> index c03a140..e009f49 100644 >> --- a/Documentation/ABI/testing/sysfs-bus-iio >> +++ b/Documentation/ABI/testing/sysfs-bus-iio >> @@ -1193,3 +1193,24 @@ Description: >> This attribute is used to read the current speed value of the >> user (which is the norm or magnitude of the velocity vector). >> Units after application of scale are m/s. >> + >> +What: /sys/.../iio:deviceX/in_steps_filter_outliers_period >> +KernelVersion: 3.20 >> +Contact: linux-iio@xxxxxxxxxxxxxxx >> +Description: >> + Specifies the number of seconds in which we compute the >> + values so we can decide if they are outlier values and >> + need to be filter out. These computed values are then >> + compared with in_steps_filter_outliers_thresh. E.g. for steps: >> + specifies number of seconds in which we compute the steps >> + that occur in order to decide if the consumer is making steps. >> + >> +What: /sys/.../iio:deviceX/in_steps_filter_outliers_thresh >> +KernelVersion: 3.20 >> +Contact: linux-iio@xxxxxxxxxxxxxxx >> +Description: >> + Specifies a threshold for filtering outlier values: if value >> + measured in in_steps_filter_outliers_period seconds is below >> + threshold, we filter it out. E.g. for steps: specifies number >> + of steps that must occur within in_steps_filter_outliers_period >> + for the pedometer to decide the consumer is making steps. >> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c >> index 4ee6fdf..81678b3 100644 >> --- a/drivers/iio/industrialio-core.c >> +++ b/drivers/iio/industrialio-core.c >> @@ -126,6 +126,8 @@ static const char * const iio_chan_info_postfix[] = { >> [IIO_CHAN_INFO_ENABLE] = "en", >> [IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight", >> [IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight", >> + [IIO_CHAN_INFO_FILTER_OUTLIERS_THRESH] = "filter_outliers_thresh", >> + [IIO_CHAN_INFO_FILTER_OUTLIERS_PERIOD] = "filter_outliers_period", >> }; >> >> /** >> diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h >> index 752a929..b6b12ac 100644 >> --- a/include/linux/iio/iio.h >> +++ b/include/linux/iio/iio.h >> @@ -41,6 +41,8 @@ enum iio_chan_info_enum { >> IIO_CHAN_INFO_ENABLE, >> IIO_CHAN_INFO_CALIBHEIGHT, >> IIO_CHAN_INFO_CALIBWEIGHT, >> + IIO_CHAN_INFO_FILTER_OUTLIERS_THRESH, >> + IIO_CHAN_INFO_FILTER_OUTLIERS_PERIOD, >> }; >> >> enum iio_shared_by { >> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-iio" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
