The feature qualifies a touch release by adding the configured touch delta value for that sensor to the sensor's current baseline value.

By doing this, the raw data-to-baseline delta created by the touch will be removed, and the touch qualification engine will see this as a

touch release event.

When the user removes a finger from a sensor that had been qualified active but has been qualified released through touch timeout, the

resulting raw-to-baseline negative delta will be aggressively tracked downward by the baseline, resulting in a sensor that remains sensi-

tive to successive touches.

The touch timeout duration is configured globally, so all inputs are monitored for the same touch duration.

If both the touch timeout feature and the mutually exclusive button group feature are enabled, the timeout timer will only run on the

touch that is externally reported as being active.

4.6 Buzzer Output

4.6.1 Introduction

The buzzer output engine produces a square wave of a configurable duration and frequency when a capacitive sensing input goes from

inactive to active. The feature can be enabled and disabled through the configuration profile. The configuration profile also includes the

settings for active duration and frequency.

No Touch, Buzzer Inactive

Device Execution

Optimized

Active

sample

sample

Active

process

additional

processing

process

additional

processing

Sleep

sleep

sleep

Figure 4.7. Effects of the Buzzer on Current Draw — Active Mode, No Touch, Buzzer Inactive

Touch Detected, Buzzer Active

Device Execution

Optimized

Active

Active

additional

processing

Sleep

sleep

(stall)

sample

process

additional

processing

sleep

(stall)

sample

process

Figure 4.8. Effects of the Buzzer on Current Draw — Active Mode, Touch Detected, Buzzer Active

CPT112S Data Sheet

Functional Description

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