TrackPad Filters Overview

To create a custom user touch and feel experience, several filters are available to control the response of the trackpad sensor.
TrackPad Filter Type

Dynamic (default) automatically adjusts the filter beta based on the speed of the finger, where as a static filter is a fixed beta independent of the speed of the finger. The advantage of dynamic filtering is when moving slowly, filtering is increased to improve accuracy and reduce jitter. When moving rapidly, the filtering is decreased to allow the sensor to be more responsive.

Range of Valid Threshold Parameters
Dynamic or Static

Affected Software Parameters
The TrackPad Filter Type parameter corresponds to the bTrackPadFilterType
member of the
tTrackPadSensorParams
type in the CapTIvate Touch Library.
TrackPad Filter Beta

This parameter sets the trackpad beta when static filtering is enabled.

Range of Valid Threshold Parameters
The TrackPad Filter Beta may be set from 0 to 255, where 0 is the strongest beta and 255 is the weakest.

Affected Software Parameters
The TrackPad Filter Beta parameter corresponds to the ui8TrackPadFilterBeta
member of the
tTrackPadSensorParams
type in the CapTIvate Touch Library.
TrackPad Filter Enable

This parameter enables trackpad filtering and is recommended for all touch applications.

Range of Valid Threshold Parameters
Enable or Disable

Affected Software Parameters
The TrackPad Filter Enable parameter corresponds to the bTrackPadFilterEnable
member of the
tTrackPadSensorParams
type in the CapTIvate Touch Library.
Dynamic Beta Top Speed

Dynamic Filter Top Speed and Bottom Speed parameters control the active range of speeds where automatic filtering beta is applied. Outside this range the beta assumes a fixed value. This parameter sets the top speed up to which the dynamic beta is allowed to automtically adjust. Speeds above this parameter cause the beta to lock at the last updated beta. Speed is calculated as the amount of change in the X or Y position axis from sample to sample and should be set appropriately for the resolution of the trackpad sensor.

Range of Valid Threshold Parameters
The Dynamic Beta Top Speed may be set from 0 to 65535 and should be set higher than the Beta Bottom Speed.

Affected Software Parameters
The TrackPad Beta Top Speed parameter corresponds to the ui16TopSpeed
member of the
tTrackPadSensorParams
type in the CapTIvate Touch Library.
Dynamic Beta Bottom Speed

Dynamic Filter Top Speed and Bottom Speed parameters control the active range of speeds where automatic filtering beta is applied. Outside this range the beta assumes a fixed value. This parameter sets the bottom speed down to which the dynamic beta is allowed to automtically adjust. Speeds below this parameter set the beta = Dynamic Filter Lower Beta. Speed is calculated as the amount of change in the X or Y position axis from sample to sample and should be set appropriately for the resolution of the trackpad sensor.

Range of Valid Threshold Parameters
The Dynamic Beta Bottom Speed may be set from 0 to 65535 and should be set lower than the Beta Top Speed.

Affected Software Parameters
The Dynamic Beta Bottom Speed parameter corresponds to the ui16BottomSpeed
member of the
tTrackPadSensorParams
type in the CapTIvate Touch Library.
Dynamic Filter Lower Beta

When using dynamic filtering, this parameter sets the filter beta when the finger movement is less than the Dynamic Beta Bottom Speed parameter.

Range of Valid Threshold Parameters
The Dynamic Filter Lower Beta may be set from 0 to 255, where 0 is the strongest beta and 255 is the weakest.

Affected Software Parameters
The Swipe Duration Threshold parameter corresponds to the ui8Lower Beta
member of the
tTrackPadSensorParams
type in the CapTIvate Touch Library.