Adjacent Key Suppression (AKS)

In designs where the sensors are close together or set for high sensitivity, multiple sensors might report detect simultaneously if touch is near them.  To allow applications to determine the intended single touch, the touch library provides the user the ability to configure a certain number of sensors in an AKS group.

When a group of sensors are in the same AKS group, then only the first strongest sensor will report detection. The sensor reporting detection will continue to report detection even if another sensor’s delta becomes stronger. The sensor stays in detect until its delta falls below its detection threshold, and then if any more sensors in the AKS group are still in detect then the strongest will report detection. So at any given time only one sensor from each AKS group will be reported to be in detect.

The library provides the ability to configure any sensor to be included in any one of the Adjacent Key Suppression Groups (AKS Group).

Setting

Variable name

Data Type

Unit

Min

Max

Typical

AKS Group

aks_group

uint8_t (3 bits)

Enum

0 (off)

7

0 (off)