Water Robustness and Detection On Capacitive Buttons

At least one non-transitory computer-readable medium containing instructions, the instructions, when loaded and executed by a processor, cause the processor to:

• identify a first high-pass filtered sequence from a plurality of sensor measurements;
• accumulate a plurality of samples from the first high-pass filtered sequence into a first accumulated value;
• compare the first accumulated value against a first threshold of accumulated values;
• based upon a determination whether the first accumulated value is greater than the first threshold of accumulated values, identify whether the sensor has been approached;
• reset the first accumulated value when:
• the first high-pass filtered sequence changes its sign;
• or
• a result of low-pass filtering the high-pass filtered sequence changes its sign;
• count a number of resets of the first accumulated value, wherein a given reset occurred after the first accumulated value exceeded an accumulation threshold during a defined time interval;
• and
• determine, through comparing the number of resets of the accumulated value within the defined time interval to a counting threshold, whether the identification of whether the sensor has been approached is false.

An apparatus, comprising:

• a processor;
• and
• at least one non-transitory computer-readable medium containing instructions, the instructions, when loaded and executed by a processor, cause the processor to:
• identify a first high-pass filtered sequence from a plurality of sensor measurements;
• accumulate a plurality of samples from the first high-pass filtered sequence into a first accumulated value;
• compare the first accumulated value against a first threshold of accumulated values;
• based upon a determination whether the first accumulated value is greater than the first threshold of accumulated values, identify whether the sensor has been approached;
• reset the first accumulated value when:
• the first high-pass filtered sequence changes its sign;
• or
• a result of low-pass filtering the high-pass filtered sequence changes its sign;
• count a number of resets of the first accumulated value, wherein a given reset occurred after the first accumulated value exceeded an accumulation threshold during a defined time interval;
• and
• determine, through comparing the number of resets of the accumulated value within the defined time interval to a counting threshold, whether the identification of whether the sensor has been approached is false.

A method, comprising:

• identifying a first high-pass filtered sequence from a plurality of sensor measurements;
• accumulating a plurality of samples from the first high-pass filtered sequence into a first accumulated value;
• comparing the first accumulated value against a first threshold of accumulated values;
• based upon a determination whether the first accumulated value is greater than the first threshold of accumulated values, identifying whether the sensor has been approached;
• resetting the first accumulated value when:
• the first high-pass filtered sequence changes its sign;
• or
• a result of low-pass filtering the high-pass filtered sequence changes its sign;
• counting a number of resets of the first accumulated value, wherein a given reset occurred after the first accumulated value exceeded an accumulation threshold during a defined time interval;
• and
• determining, through comparing the number of resets of the accumulated value within the defined time interval to a counting threshold, whether the identification of whether the sensor has been approached is false.