For an overview of QTouch method based capacitive touch acquisition, refer Section 5.2.1 QTouch Acquistion method.
The QTouch Library for ATtiny40 device allows for Sensor configuration and Sensor Acquisition parameter setting. Based on the input Sensor configuration, the QTouch Library takes care of the capacitive touch acquisition data capture operations on the external capacitive touch sensors. The captured Touch Data and Touch Button ON/OFF Status information is then available for user application.
The diagram below indicates a Typical Sensor arrangement using the Tiny40 device. For one channel configuration, two ADC pins are used for acquisition. For number of touch buttons greater than one, no extra ADC pins are used. Port pins PA0 to PA7 and PB0 to PB3 can be used to support upto 12 Touch Buttons. The Touch Buttons may be connected anywhere on the said port pins.
The Sensor numbering is always in the increasing order of Port pin.
