Method and apparatus to measure self-capacitance using a single pin
First Claim
1. A non-transitory computer-readable medium comprising instructions winch, when implemented by one or more machines, cause the one or more machines to;
- control a first switch to charge a reference capacitor to a first voltage level by applying a first voltage to a conductor of the reference capacitor, the reference capacitor coupled to an input of an Analog to Digital Converter (ADC), the first voltage level being a difference between the applied first voltage and a reference voltage;
receive a first analog signal from a touch sensor electrode at the input of the ADC;
convert the first analog signal to a first digital value provided at an output of the ADC;
control a second switch to charge the reference capacitor to a second voltage level by applying a second voltage to the conductor of the reference capacitor, the second voltage opposite in polarity to the first voltage, the second voltage level being a difference between the applied second voltage and the reference voltage;
receive a second analog signal from the touch sensor electrode at the input to the ADC;
convert the second analog signal to a second digital value at the output of the ADC; and
detect a touch to the touch sensor device based on the first digital value.
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Accused Products
Abstract
A method may include controlling a first switch to charge a reference capacitor to a first voltage level by applying a first voltage. The method may also include receiving a first analog signal from a touch sensor electrode at an input of an Analog to Digital Converter (ADC) and converting the first analog signal to a first digital value provided at an output of the ADC. In certain embodiments, the method may additionally include controlling a second switch to charge the reference capacitor to a second voltage level by applying a second voltage, receiving a second analog signal from the touch sensor electrode at the input to the ADC, and converting the second analog signal to a second digital value at the output of the ADC. The method may further include detecting a touch to the touch sensor device based on the first digital value.
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Citations
20 Claims
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1. A non-transitory computer-readable medium comprising instructions winch, when implemented by one or more machines, cause the one or more machines to;
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control a first switch to charge a reference capacitor to a first voltage level by applying a first voltage to a conductor of the reference capacitor, the reference capacitor coupled to an input of an Analog to Digital Converter (ADC), the first voltage level being a difference between the applied first voltage and a reference voltage; receive a first analog signal from a touch sensor electrode at the input of the ADC; convert the first analog signal to a first digital value provided at an output of the ADC; control a second switch to charge the reference capacitor to a second voltage level by applying a second voltage to the conductor of the reference capacitor, the second voltage opposite in polarity to the first voltage, the second voltage level being a difference between the applied second voltage and the reference voltage; receive a second analog signal from the touch sensor electrode at the input to the ADC; convert the second analog signal to a second digital value at the output of the ADC; and detect a touch to the touch sensor device based on the first digital value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method, comprising:
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controlling a first switch to charge a reference capacitor to a first voltage level by applying a first voltage to a conductor of the reference capacitor, the reference capacitor coupled to an input of an Analog to Digital Converter (ADC), the first voltage level being a difference between the applied first voltage and a reference voltage; receiving a first analog signal from a touch sensor electrode at the input of the ADC; converting the first analog signal to a first digital value provided at an output of the ADC; controlling a second switch to charge the reference capacitor to a second voltage level by applying a second voltage to the conductor of the reference capacitor, the second voltage opposite in polarity to the first voltage, the second voltage level being a difference between the applied second voltage and the reference voltage; receiving a second analog signal from the touch sensor electrode at the input to the ADC; converting the second analog signal to a second digital value at the output of the ADC; and detecting a touch to the touch sensor device based on the first digital value. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. An apparatus, comprising:
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one or more processors; and one or more memory units coupled to the one or more processors, the one or more memory units collectively storing logic configured to, when executed by the one or more processors, cause the one or more processors to perform operations comprising; controlling a first switch to charge a reference capacitor to a first voltage level by applying a first voltage to a conductor of the reference capacitor, the reference capacitor coupled to an input of an Analog to Digital Converter (ADC), the first voltage level being a difference between the applied first voltage and a reference voltage; receiving a first analog signal from a touch sensor electrode at the input of the ADC; converting the first analog signal to a first digital value provided at an output of the ADC; controlling a second switch to charge the reference capacitor to a second voltage level by applying a second voltage to the conductor of the reference capacitor, the second voltage opposite in polarity to the first voltage, the second voltage level being a difference between the applied second voltage and the reference voltage; receiving a second analog signal from the touch sensor electrode at the input to the ADC; converting the second analog signal to a second digital value at the output of the ADC; and detecting a touch to the touch sensor device based on the first digital value. - View Dependent Claims (18, 19, 20)
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Specification