3.3.3.2 KEY_x_PARAMS

Defines the sensor's detect threshold. When a finger touches the sensor, the touch delta increases. The sensor will be reported as touched only if the sensor's touch delta value is more than the Sensor Threshold. It is recommended to configure the Sensor Threshold as 50~70% of touch delta. It is good to start with the default value and adjust after monitoring the touch delta value.

Under noisy conditions, the delta value goes up and down over the sensor threshold. During these conditions, the sensor dithers in and out of touch. To avoid this, once a sensor goes into the detect state, the threshold for the sensor is reduced by the hysteresis value. Hysteresis values are derived from the "Sensor Threshold" value.

It is not enough for the delta to go below the threshold for the sensor to report no touch. It has to go below the hysteresis level to declare no touch. Refer to the following image.

There are four different hysteresis levels available to choose from.

AKS can be used when touching multiple sensors is NOT allowed in a system. When sensors are physically close to each other, there is a possibility that touching one sensor will result in increasing touch delta value on other adjacent sensors. At times the delta rise in other sensors may cross the threshold and could report false detection. When such sensors are configured in the same AKS group, only the first sensor (which goes in to detect) will be reported as touched. All other sensors' states will be suppressed, even if their delta crosses the Sensor Threshold.