4.3 Capacitive Proximity Sensing

4.3.1 Wake on Proximity

The wake on capacitive proximity detection engine monitors for the presence of a conductive object such as a hand to move within

detectable range of the sensor. When the engine detects an object, the device wakes from sleep and can begin qualifying touch events

on all sensors enabled for active mode sensing.

4.3.2 Proximity Configuration

The proximity sensing feature uses a single sensor input for proximity qualification. The configuration profile stores the pin chosen by

the user. The sensor used for proximity qualification should also have a drive strength setting that is as high as possible without saturat-

ing the input when no conductive object is in proximity to the proximity sensor. The accumulation setting of the input is also configura-

ble.

The proximity threshold controls the sensitivity of the input. A lower threshold setting increases sensitivity and increases the range of

the sensor.

A proximity sensing input cannot be used for touch qualification, and so the active and inactive thresholds are not used for proximity

sensors. Additionally, the proximity input has no effect on other components of the device such as mutually exclusive button groups,

buzzer output, touch time out timers, and sliders.

4.4 Slider

The device supports creation of a single slider that is composed of two or more capacitive sensing input pins. The pins chosen as slider

inputs are assigned to the slider feature through the configuration profile.

The configuration profile also stores a value designated as the highest positional value that can be derived by the slider engine. That

highest value is used to derive the values of all intermediate positions on the slider array.

CPT112S Data Sheet

Functional Description

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